Astronomy: Unit 1 Exam Review
Johannes Kepler contributions
-studied motion of planets = by 1606 saw mars orbit was ellipse, not uniform speeds, period of orbits related to orbits radius =Kepler's three laws of planetary motion
The Perseid meteor shower is named after a(n) _____.
Constellation
All around the world, ancient cultures celebrated heroes, gods, and mythical beasts by naming groups of stars called ___.
Constellations
_________ are also used to locate specific areas in the sky.
Constellations
The problem of the place of Earth was resolved by the ___.
Copernican Revolution
The problem of the place of Earth was resolved by the _____. Copernican Revolution Ptolemaic Revolution Aristotelian Revolution Newtonian Revolution
Copernican Revolution
The problem of the place of Earth was resolved by the...
Copernican Revolution
The moons of Jupiter supported the ____ of the universe over the ptolemaic model
Copernican model
The moons of Jupiter supported the _____ of the universe over the Ptolemaic
Copernican model
The moons of Jupiter supported the__________of the Universe over the Ptolemaic model.
Copernican model
__________is one of the small bodies that formed from the solar nebula and eventually grew into protoplanets
A planetesimal
_____ is a telescope that forms images by bending light with a lens.
A refracting telescope
__________is a graph of orbital velocity versus radius in the disk of a galaxy.
A rotation curve
____ is the event that occurs when the moon passes directly between Earth and the sun, blocking your view of the sun.
A solar eclipse
_____ is the event that occurs when the Moon passes directly between Earth and the Sun, blocking your view of the Sun. A solar eclipse The winter solstice A lunar eclipse The summer solstice
A solar eclipse
______ is the event that occurs when the Moon passes directly between Earth and the sun blocking your view of the sun
A solar eclipse
Total solar eclipse
A solar eclipse in which the moon completely covers the bright surface of the sun
Partial solar eclipse
A solar eclipse in which the moon does not completely cover the sun
annular eclipse
A solar eclipse in which the solar photosphere around the edge of the moon in a bright, ring, or annulus. The corona, chromosphere, and prominences cannot be seen
Which telescope has the largest light-gathering power among the following telescopes? A telescope of diameter 6 cm and focal length 100 cm A telescope of diameter 2 cm and focal length 100 cm A telescope of diameter 5 cm and focal length 50 cm A telescope of diameter 3 cm and focal length 75 cm
A telescope of diameter 6 cm and focal length 100 cm
2) Why do solar eclipses happen only at new moon? Why not every new moon?
Because the Earth, Sun and Moon have to be in a straight line, then the eclipse can occur and that happens only at the new moon.
Which of the following systems cannot be analyzed as a visual binary?
Binary stars orbiting so close to each other that they are not visible as separate stars
Which of the following statements is true of an electron?
Binding energy is large when a large amount of energy is needed to pull an electron away from an atom
The strong nuclear force is involved in:
Binding together atomic nuclei
___ is a mass that has collapsed to such a small volume that its gravity prevents the escape of all radiation.
Black hole
A small, dark cloud, only about 1 light-year in diameter, that contains 10 to 1000 solar masses of gas and dust.
Bok Globule
A very cool, low-luminosity star that doesn't have enough mass to ignite nuclear fusion.
Brown Dwarf
Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the ___ that slid around a larger circle called the deferent.
Epicycle
10. The average distance from Venus to the Sun is about 2 AU.
False
2. The nearest star to the Sun is Sirius
False
3. A supercluster is a cluster of supergiants
False
5. Spiral arms are concentrated at the center of our Galaxy.
False
6. The average distance between Earth and the Sun is called a light-year.
False
7. The Sun is a nonluminous ball of hot gas.
False
8. Venus is about the size of Earth's Moon.
False
9. The field of view of an image is limited to the half of the visible part of the image.
False
A big rip is inevitable in the near future.
False
A lunar eclipse always reaches totality.
False
A meteor that survives its passage through the atmosphere and strikes the ground is called a meteoroid.
False
A star can remain in the giant-star stage for about 90 percent of its total lifetime before it dies
False
A supercluster is a cluster of supergiants. TRUE OR FALSE
False
An expanding shell of gas ejected from a medium-mass star during the latter stages of its evolution is known as a black hole.
False
An object in a stable orbit continuously misses Earth because of its vertical velocity.
False
Ancient Astronomers called the brightest stars in a constellation sixth-magnitude stars
False
Ancient astronomers called the brightest stars in a constellation sixth magnitude stars. TRUE OR FALSE
False
Ancient astronomers called the brightest stars in a constellation sixth-magnitude stars (T or F)
False
Because Copernicus imposed uniform circular motion on his model, it was able to accurately predict the motions of the planets.
False
Convection is a mode of energy transport between materials that requires close contact between the atoms
False
Cool stars emit a great deal of ultraviolet radiation that you can't see, and hot stars emit plenty of infrared radiation
False
Earth is the smallest of the Terrestrial worlds, but it is big compared with the Jovian planets.
False
Electromagnetic waves with wavelengths shorter than gamma rays are called infrared radiation
False
If the distance from Earth to the Moon were doubled, the gravitational force between them would increase by a factor of 22, or 4.
False
In a Hertzsprung-Russell (H-R) diagram, points near the top of the diagram represent very low luminosity stars and points near the bottom represent very luminous stars
False
In the H-R diagram, points near the top of the diagram represents very low luminosity stars and points near the bottom represents very luminous stars
False
In the context of a redshift and a blueshift, red and blue refer to the actual cover of light.
False
In the context of granulation, convection occurs when hot fluid sins and cool fluid rises
False
In the copernican model, Venus moves around an epicycle centered on a line between Earth and the sun (T or F)
False
In the distance from Earth to the moon were doubled, the gravitational force between them would increase by a factor of 22, or 4 (T or F)
False
Isotropy is the observation that, in its general properties, the Universe looks different in every direction.
False
Jupiter is considered a near Earth object.
False
Jupiter, Saturn, Uranus and Neptune are only located at a distance of 1 AU or less from the Sun.
False
Kiloparsec is a unit of sound
False
O and B associations are poor spiral tracers.
False
Photos of Jupiter's rings show that they are very bright when they are scattering light backward.
False
Proper motion of a star is measured in meters.
False
Radial velocity is that component of an object's velocity that is directed perpendicular to an observer's line of sight
False
Scientists have located evidence that suggests that Earth has experienced at least seven different ice ages throughout its history.
False
Spiral Seyfert galaxies are very similar to the giant elliptical galaxies that have double radio lobes.
False
Spiral arms are concentrated at the center of our Galaxy (T or F)
False
Stellar parallax is the shift seen across a baseline of 2 AU rather than 1 AU.
False
Sunspots are hot spots on the Sun's surface caused by weak magnetic fields
False
TF- The planets did not form from the same disc as their star.
False
TF- in terms on keplers laws of motion, The travel time for each segment is different.
False
The Big Dipper is an officially recognized constellation
False
The Big Dipper is an officially recognized constellation.
False
The Oort cloud is filled with stony-iron meteorites.
False
The apparent visual magnitude takes into account the distance to stars.
False
The average distance from Venus to the sun is about 2 AU (T or F)
False
The celestial sphere actually does exist.
False
The centers of stars are many millions of degrees cooler than their surfaces
False
The centers of stars are many millions of degrees cooler than their surfaces.
False
The condensation hypothesis proposes that the Moon formed when an object estimated to have been at least as large as Mars smashed into the proto-Earth.
False
The dominant trigger of star formation in our Galaxy is supernova explosions.
False
The human eye can see both infrared and ultraviolet light.
False
The instability strip is the region of the H-R diagram in which stars are stable to pulsation
False
The light colored mountainous lunar highlands are called maria. T or F
False
The moon orbits eastward around Earth once a year (T or F)
False
The parallax of the stars is very big and can be easily seen with the unaided eye
False
The rings of uranus are easily visible from earth
False
The scientific method is a simple, mechanical way of grinding facts into understanding
False
The summer solstice occurs approximately December 21 and is considered the longest day of the year for the Northern Hemisphere.
False
The sun is a nonluminous ball of hot gas. TRUE OR FALSE
False
Uranus and neptune are referred to as the gas giants
False
Uranus is one of a group of dwarf planets and other small objects that have been discovered circling the Sun beyond Neptune.
False
Uranus rotates with its equator almost parallel to its orbit.
False
Venus is about the size of earth's moon. TRUE OR FALSE
False
When the summer solstice occurs in the Northern Hemisphere, the Southern Hemisphere is tilted toward the sun and receives the most direct sunlight.
False
Y dwarfs are substellar objects with temperature above 500 K
False
an object in a stable orbit continuously misses Earth because of its vertical velocity (T or F)
False
phobos is the smallest moon of jupiter
False
equation for gravitational force
Fgravity = GMm/d^2 G = universal constant of gravity M = mass of larger object m = mass of smaller object d = distance (squared) =proportional to product of masses, inversely proportional to distance squared =if one mass is doubled, force is doubled -net force increases as distance decreases = if 1/4 distance, 16x larger force
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from _____. geometric models careful observations first principles personal experience
First Principles
The ignition of helium in the core of a star changes the structure of the star. The star now makes energy in two locations by different processes
Helium fusion in the core and hydrogen fusion in the surrounding shell
Among the following electromagnetic waves, photons of which electromagnetic radiations carry the highest energy?
Gamma rays
In the context of the electromagnetic spectrum which of the following types of electromagnetic radiation has the smallest wavelength
Gamma rays
In the context of the electromagnetic spectrum, which of the following types of electromagnetic radiation has the smallest wavelength?
Gamma rays
What is the largest moon in the solar system?
Ganymede
___ is the largest moon in the Solar System.
Ganymede
In 1916, Einstein published his__________that described gravity as a curvature of space-time
General theory of relativity
Ptolemy's model of the universe was
Geocentric
A(n) ______ is a model of the Universe with the Sun at the center, such as the Copernican Universe
Heliocentric Universe
The study of the interior of the Sun by the analysis of its modes of vibration is called ___.
Helioseismology
Inside the core of the star, hydrogen fuses into what other element?
Helium
The sun in primarily composed of hydrogen and ____
Helium
The process in which atoms lose or gain electrons is referred to as
Ionization
Which of the following is true of the eccentricity of an ellipse?
It tells you the shape of an ellipse
__________is microscopic solid grains in the interstellar medium.
Interstellar dust
_____ is the process in which dust scatters blue light out of starlight and makes the stars look redder.
Interstellar reddening
Which of the following is the most geological active moon?
Io
___ is the conflict between theory and evidence regarding the darkness of the night sky.
Olber's Paradox
On the autumnal equinox, the sun is:
On the celestial equator and moving south with respect to the equator
Ninety percent of all normal stars in a Hertzsprung-Russell (H-R) diagram are:
On the main sequence
Kepler's third law of planetary motion states that:
Orbital period and semi-major axis was related
When the weight of a spinning top, which causes it to tip over, combines with the top's rapid rotation and makes its axis sweep out the shape of a cone, that motion is known as _____. precession revolution eccentricity conjunction
Precession
__________ is a change in the orientation of the rotational axis of a rotating body.
Precession
Which of the following is true of redshift?
Radiation that comes from great distance has tremendous redshift.
In the context of the electromagnetic spectrum, which of the following types of electromagnetic radiation has the longest wavelength?
Radio waves
_____ is the motion around an axis passing through the spinning body. Rotation Projection Revolution Precession
Rotation
is the motion around an axis passing through the spinning body
Rotation
What is the powerful radio source at the center of our galaxy?
Sagittarius A*
The early astronomers imagined that the entire Universe was enclosed inside the celestial sphere that lay just beyond the planet ___.
Saturn
The early astronomers imagined that the entire Universe was enclosed inside the celestial sphere that lay just beyond the planet _____. Saturn Mars Uranus Jupiter
Saturn
Which of the following is a planet that is visible to the naked eye from Earth?
Saturn
If you take a photograph of a nearby star and after 6 months take another photograph of the star from a lighty different location in space, you would observe that the
Star is not in exactly the same place in the two photographs
The__________is a theory that proposed to account for spiral arms as compressions of the interstellar medium in the disk of the galaxy.
Spiral density wave theory
Of all the galaxies, _____ are easiest to notice.
Spiral galaxies
The light gathering power of a telescope is directly proportional to the
Square of the diameter of the primary mirror or lense
A sphere of gas held together by gravity that generates its own energy.
Star
In the Ptolemaic model, Mercury and Venus had to be treated differently from the rest of the planets: Their epicycles had to remain centered on the Earth-Sun line. T/F
T
In the context of the Sun's surface glowing when hot, yellow-hot is hotter than red-hot but not as hot as white-hot. T/F
T
Radio astronomers face a problem of radio interference analogous to light pollution. T/F
T
Spiral arms help in star formation. T/F
T
The tip of the moon's umbra sweeps the path of totality for a solar eclipse out as the umbra moves over Earth.
T
The totally eclipsed moon glows coppery red because sunlight reaches the moon's surface after passing through Earth's atmosphere.
T
The umbra of the moon's shadow is the region from which no part of the photosphere is visible.
T
Two bodies revolve around their common center of mass, the balance point of the system. T/F
T
Which of the following is true of Copernicus's model of the Universe? Earth was considered to be at the center. Each planet was treated differently. The positions of the planets were predicted accurately. Each planet followed orbits that circled the Sun at the center.
Each planet followed orbits that circled the Sun at the center. Correct. In Copernicus's model, all of the planets were treated the same. They all followed orbits that circled the Sun at the center.
Which of the following is true of Copernicus's model of the Universe?
Each planet followed orbits that circled the sun at the center
Which of the following is true of the Copernicus's model of the universe
Each planet followed orbits that circled the sun at the center
The most astonishing consequence of the Copernican hypothesis was what it asserted about _______.
Earth
What is an example of a terrestrial planet?
Earth
___ is considered to be an active planet because it has a molten interior and heat flowing outward that powers volcanism, earthquakes, and an active crust.
Earth
___ are similar in size.
Earth and Venus
_____ are similar in size.
Earth and Venus
Perihelion
Earth at its closest point to the sun
The observation of the moons of Jupiter by Galileo Galilei suggested that:
Earth could move and keep its moon.
pull, center, straight, gravitation, third, pairs, attracts, mutual, universal, matter, gravity, no weight, matter
When Newton thought carefully about motion, he realized that some force must ____ the Moon toward Earth's ____. If there were no such force altering the Moon's motion, it would continue moving in a _______ line and leave Earth forever. It can circle Earth only if Earth attracts it. Newton's insight was to recognize that the force that holds the Moon in its orbit is the same as the force that makes apples fall from trees. Newtonian ________ is sometimes called universal mutual gravitation. Newton's ____ law points out that forces occur in ____. If one body _______ another, the second body must also attract the first. Thus, gravitation is _______. Furthermore, gravity is _________. That is, all objects with mass attract all other masses in the Universe. The mass of an object is a measure of the amount of _______ in the object, usually expressed in kilograms. Mass is not the same as weight. An object's weight is the force that Earth's ______ exerts on the object. Thus an object in space far from Earth might have ___ _________, but it would contain the same amount of ______ and would thus have the same mass that it has on Earth.
Which of the following statements is true of an eclipsing binary system?
When one star moves in front of the other, it blocks some of the light.
velocity, mass, center, circular velocity
When the captain of a spaceship says to the pilot, "Put us into a circular orbit," the ship's computers must quickly calculate the __________ needed to achieve a circular orbit. That circular velocity depends only on the _______ of the planet and the distance from the __________ of the planet. Once the engines fire and the ship reaches __________ __________, the engines can shut down. The ship is in orbit and will fall around the planet forever, as long as it is above the atmosphere's friction. No further effort is needed to maintain orbit, thanks to the laws Newton discovered (See Circular Velocity in the Math Reference Cards MR).
Observations and stellar evolution models indicate that the central star of a planetary nebula finally must contract and become a _____.
White Dwarf
________ is the hazy band of light that circles our sky, produced by the glow of our galaxy.
The milky way
Which if the following is true of the moon orbiting Earth
The moon orbits eastward around Earth once a month
Rotation
The turning of a body about an axis through its center. The ear rotates on its axis once a day.
Suppose you are observing a light bulb. In this context, which of the following is a difference between intrinsic brightness and apparent brightness?
The wattage of the light bulb tells you its intrinsic brightness, whereas the apparent brightness of the light bulb depends on its distance from you.
_____ is the location in the H-R diagram where stars first reach stability as hydrogen-burning stars
The zero-age main sequence
A scientifically accepted set of principles that explains a natural phenomena.
Theory
Which of the following is true of early astronomers?
They thought the entire Universe consisted of Earth, the Sun, the Moon, and five other planets.
Which of the following is true of early astronomers? They knew that the planets were made of rock and gas, much like Earth. They thought that stars were other objects like the Sun and that we lived inside a galaxy. They thought the entire Universe consisted of Earth, the Sun, the Moon, and five other planets. They knew that there were many other galaxies in the Universe.
They thought the entire Universe consisted of Earth, the Sun, the Moon, and five other planets.
Which of the following is true of P waves?
They travel like sound waves.
A lunar eclipse that occurs when the Moon moves completely into Earth's umbral shadow is called a _____. total lunar eclipse total solar eclipse penumbral lunar eclipse partial solar eclipse
Total Lunar Eclipse
If the orbit of the Moon carries it through the umbra of Earth's shadow, you see a__________. partial lunar eclipse partial solar eclipse total lunar eclipse total solar eclipse
Total lunar eclipse
__________refer to rare occasions when Venus can be seen as a tiny dot directly between Earth and the Sun. Solar phenomena of Venus Transits of Venus Meteors of Venus Light pillars of Venus
Transits of Venus
refers to rare occasions when venus can be seen as a tiny dot directly between Earth and the Sun
Transits of Venus
1. Light from Proxima Centauri takes 4.2 years to reach Earth
True
A scientific hypothesis must be testable.
True
According to the period-luminosity relation, the long-period Cepheids are more luminous than the short-period Cepheids.
True
All of the volcanoes on mars are shield volcanoes
True
An intrinsically very bright stars might appear faint if it is far away
True
Ancient astronomers believed that Earth did not move because they saw no parallax
True
Ancient astronomers believed that Earth did not move because they saw no parallax (T or F)
True
Apparent visual magnitude describes the way the stars look to the human eyes observing from Earth.
True
Apparent visual magnitudes describe how stars look to human eyes observing from Earth.
True
As the moon grows fatter from new to full it is said to wax TRUE OR FALSE
True
As the moon grows fatter from new to full, it is said to wax (T or F)
True
Both Jupiter and Saturn radiate more heat than they absorb from the Sun.
True
Modern astronomers know the stars are scattered through space at different distances.
True
New technology allows astronomers to accurately measure the brightness of the stars.
True
Once a protoplanet approached a mass of 15 Earth masses or so, it could begin to grow by gravitational collapse.
True
Ptolemy's theory weakened the principles of geocentrism and the arguments for uniform circular motion within the solar system.
True
TF- It has been hypothesized that there is a supermassive black hole at the center of the Milky Way Galaxy.
True
TF- The amount of the entire surface of the Moon illuminated by sunlight is the same at all positions.
True
TF: E = mc2 is the most famous equation in Physics.
True
The geocentric model assumed that the sun, moon, stars, and other planets circled Earth.
True
The moon must first pass through the penumbra before reaching the umbra.
True
The outer atmosphere of the sun is visible during a total solar eclipse.
True
The particles inside a hot object are less agitated than the particles in a cool object
True
The planets in our solar system produce no visible light of their own.
True
The same principles of proving a criminal case are vastly similar to proving a scientific hypothesis.
True
The seasons result from the tip of the Earth's equator and axis relative to its orbit
True
To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant
True
Two bodies revolve around their common center of mass, the balance point of the system
True
Uranus never grew massive enough to capture large amounts of gas from the solar nebula as Jupiter and Saturn did, so it has much less hydrogen and helium.
True
Venus is visible in the west after sunset or in the east before sunrise (T or F)
True
When the bright photosphere is covered, the corona, chromospheres, and prominences are visible.
True
Rotation
Turning of a body about its axis through its center
The ______ of an object is the angular distance from one edge to the other
angular diameter
A(n) ___________ eclipse occurs when the moon is at its greatest distance from Earth, and the moon is new.
annular
A(n)__________occurs when the Moon is at its greatest distance from Earth and the Moon is new.
annular solar eclipse
Absolute visual magnitude is the:
apparent magnitude of a star observed from a distance of 10 pc.
parallax
apparent motion of object because of motion of observer -too small to see with unaided eye
The Sun is on the celestial equator during the:
autumnal equinox and the vernal equinox.
The Sun is on the celestial equator during the: summer solstice and the winter solstice. autumnal equinox and the winter solstice. vernal equinox and the summer solstice. autumnal equinox and the vernal equinox.
autumnal equinox and the vernal equinox.
A lunar eclipse occurs when a. the sun passes between Earth and Earth's moon. b. Earth passes between the Earth's moon and the sun. c. the Earth's moon passes between Earth and the sun.
b
A solar eclipse occurs when a. the sun passes between Earth and Earth's moon. b. Earth passes between the Earth's moon and the sun. c. the Earth's moon passes between Earth and the sun.
c
A solar eclipse that occurs when the moon's umbra does not reach Earth's surface is called a. a total solar eclipse. b. a partial solar eclipse. c. an annular solar eclipse. d. a penumbral solar eclipse. e. an umbral solar eclipse.
c
A total lunar eclipse is a. visible only from the path of totality. b. visible only during a new moon. c. visible to all observers on the side of Earth from which the moon would be visible at that time. d. an opportunity to study the corona of the sun. e. none of the above
c
During a total lunar eclipse a. the moon must be new. b. the observer must be in the path of totality. c. the moon will glow a coppery red. d. the moon must be at its greatest distance from Earth. e. the date must be near the date of one of the equinoxes.
c
If the moon enters Earth's shadow but does not reach the umbra, the eclipse is termed a. partial. b. umbral. c. penumbral. d. total. e. annular.
c
The moon moves about _________ eastward in the sky each night. a. 1° b. 5° c. 13° d. 27.3° e. 29.5°
c
When will the full moon be highest above the southern horizon for an observer in the Northern Hemisphere? a. at midnight near the summer solstice b. at midnight near the vernal equinox c. at midnight near the winter solstice d. at midnight near the vernal equinox e The angle between the southern horizon and the full moon at midnight does not change with the seasons.
c
21. The average distance from Mars to the Sun is _____.
c. 1.5 AU
20. Which of the following numbers is the largest?
c. 4.35 × 1010
In the context of light curves, observations of an eclipsing binary system can directly tell astronomers not only the masses of its stars but also their ___.
diameters
The first stage of Earth's evolution is ___.
differentiation
___ is the separation of materials according to density.
differentiation
The halo in the Milky Way is a part of the ___ of the galaxy.
disk component
According to astronomers, the Milky Way is ___.
disk shaped
The major components of the Milky Way Galaxy include the ___.
disk, halo and central bulge
The process by which a rotating, convecting body of conducting matter, such as in Earth's core or in the Sun's convection zone, can generate a magnetic field is referred to as the ___.
dynamo effect
A marble has a diameter of 2 cm. At what distance would the marble have an angular diameter of 1 arc second? Here one radian is 57.3 degrees, and one arc second is 1/3600 of a degree. a. 4.1 cm b. 4.1 miles c. 4.1 m d. 4.1 ft e. 4.1 km
e
During an annular eclipse, the moon's umbral shadow is too a. bright to produce a total solar eclipse. b. faint to produce a total solar eclipse. c. wide to produce a total solar eclipse. d. long to produce a total solar eclipse. e. short to produce a total solar eclipse.
e
A binary star system in which the stars cross in front of each other as seen from Earth.
eclipsing binary
A(n) ___ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant.
ellipse
A(n) _____ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant.
ellipse
a ______ is a closed curve around 2 points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant
ellipse
The__________of a lens or mirror is the distance from that lens or mirror to the point where it focuses parallel rays of light. image distance radius of curvature focal length object distance
focal length
Scientists have found evidence that suggests Earth has experienced at least how many different ice ages throughout its history?
four different ice ages
A large system of stars, gas, and dust orbiting a common center of mass.
galaxy
Among the following electromagnetic waves, photons of which electromagnetic radiations carry the highest energy?
gamma rays
A(n) _____ is a model universe with Earth at the center, such as the Ptolemaic Universe. eccentric universe heliocentric universe concentric universe geocentric universe
geocentric universe Correct. A geocentric universe is a model universe with Earth at the center, such as the Ptolemaic Universe.
A(n) ____ is one in which an object orbiting Earth has an orbital period equal to the rotation period of Earth. heliocentric orbit epicyclical orbit open orbit geosynchronous orbit
geosynchronous orbit Correct. A geosynchronous orbit is one in which an object orbiting Earth has an orbital period equal to the rotation period of Earth.
The linear relation between the distance to galaxies and the apparent velocity of recession.
hubble law
Analysis of the solar spectrum shows that the Sun is mostly ___.
hydrogen
In stellar astronomy, ___ states that the weight of each layer of a star must be supported by the layer below.
hydrostatic equilibrium
A(n) _________ is an attempt to answer the questions before performing any experiments.
hypothesis
When following the scientific method, scientists will form an educated guess after making observations. This educated guess is also known as a _______.
hypothesis
Titan's surface is mainly composed of _____.
ices of water and methane
The main reason for connecting two or more telescopes in an interferometer is to:
improve resolving power.
The small cluster of a few dozen galaxies that contains the Milky Way Galaxy.
local group
mass
measure of amount of matter; doesn't change with gravity
heliocentric model
model universe with sun at center: Copernicus's model
The photons of blue light :
more energy than the photons of red light
The photons of blue light have:
more energy than the photons of red light.
In their attempt to gauge the true shape of our Galaxy, the Herschels concluded that:
our Galaxy has some noticeable holes lacking stars around its edges.
The creation of a planetary atmosphere from a planet's interior is called ___.
outgassing
_________are the large oval grooves found on Uranus's moon Miranda that indicate past geologic activity.
ovoids
One ___ equals the distance to an imaginary star that has a parallax of 1 arc second.
parsec
A(n) ________ solar eclipse occurs when the path of the moon is "off-center" and, therefore, only part of the sun is covered.
partial
During a solar eclipse, if you moved into the ______, You would be in partial shadow and would also see part of the sun peeking around the end of the moon.
penumbra
During a solar eclipse, if you moved into the__________, you would be in partial shadow and would also see part of the Sun peeking around the edge of the Moon.
penumbra
The relation between the period of pulsation and intrinsic brightness among Cepheid variable stars is called ___.
period luminosity relationship
Dark age
period of time after the glow of the big bang faded into the infrared, but before the birth of the first stars, in which the universe expanded into darkness
The solar nebula theory supposes that
planets form in rotating disks of gas and dust around young stars.
What is a "soup of unattached particles"?
plasma
Which of the following is a prototype of a new class of objects defined by the International Astronomical Union (IAU) as dwarf planets?
pluto
In a Hertzsprung-Russell (H-R) diagram, a star is represented by a ___ on the graph that tells you its luminosity and temperature.
point
In a Hertzsprung-Russell (H-R) diagram, a star is represented by a _____ on the graph that tells you its luminosity and temperature.
point
Earth's axis would remain pointed constantly toward a spot near the star Polaris except for the effect of _____.
precession
The twisting of the axis of rotation combined with the rotation of an object causes _____
precession
When the weight of a spinning top, which causes it to tip over, combines with the top's rapid rotation and makes its axis sweep out the shape of a cone, that motion is known as _____.
precession
When the weight of a spinning top, which causes it to tip over, combines with the top's rapid rotation and makes its axis sweep out the shape of a cone, that motion is known as _______
precession
A ___ is composed of ionized gas trapped in a magnetic arch rising up through the photosphere and the chromosphere into the lower corona
prominence
A ___ is composed of ionized gas trapped in a magnetic arch rising up through the photosphere and the chromosphere into the lower corona.
prominence
The rate at which a star moves across the sky, in arc seconds per year.
proper motion
A ___ is a collapsing cloud of gas and dust destined to become a star.
protostar
force
push or pull on object from interaction with another
Among the following electromagnetic waves, photons of which electromagnetic radiations carry the lowest energy?
radio waves
In the context of the electromagnetic spectrum which of the following types of electromagnetic radiation has the longest wavelength
radio waves
precession
rapid rotation makes its axis sweep in a conical motion
Stars less massive than about 0.4 solar masses are referred to as ___.
red dwarfs
The most luminous stars in elliptical galaxies are:
red giants
A ___ has a main mirror called the primary mirror.
reflecting telescope
Radio telescopes are _____.
reflecting telescopes
The statement "The albedo of the near side of the Moon is 0.12" implies that the Moon
reflects only 12 percent of the light that hits it.
___ is a telescope that forms images by bending light with a lens.
refracting telescope
Copernicus could explain the __________ motion of the planets without using the complicated epicycles described by the Ptolemaic model.
retrograde
The occasional backward motion of the planets against the background of fixed stars is called ___.
retrograde motion
the occasional backward motion of the planets against the background of fixed stars is called _____
retrograde motion
A telescope that suffers from chromatic aberration and has a low light-gathering power is most likely a:
small diameter refracting telescope.
During a(n) _______ eclipse, the moon passes in front of the sun.
solar
Earth goes through a cycle of seasons because of changes in the amount of ________ that Earth's Northern and Southern hemispheres receive at different times of the year.
solar energy
Earth does not seem to move from the perspective of an earthbound observer, which once gave rise to the assumption that the planet is ________.
solid, stable, and unmoving
The star Alpha Centauri cannot be seen from most of the United States due to its location in the ____________ sky.
southern
Asteroids are examples of ___.
space debris
A _____ is a device that separates light by wavelengths to produce a spectrum. lens mirror interferomoter spectrograph
spectrograph Correct. A spectrograph is a device that separates light by wavelengths to produce a spectrum. To analyze light in detail, you need to spread the light out according to wavelength into a spectrum.
speed, velocity, acceleration
speed = rate an object moves; distance/time velocity = speed and direction; distance/ time with direction acceleration = any change in velocity (speed or direction); distance/time^2
The central bulge in the Milky Way is a part of the ___ of the galaxy.
spherical component
Of all the galaxies, ___ are easiest to notice.
spiral
The ___ are long sweeping segments containing bright stars, star clusters, gas, and dust.
spiral arms
What type of galaxy is the Milky Way Galaxy?
spiral galaxy
Objects of known brightness that astronomers use to find distance.
standard candles
A(n) ________ is a luminous ball of hot gas that has the ability to generate its own energy.
star
A ___ is a group of stars that formed together and orbit a common center of mass.
star cluster
A _____ is a group of stars that formed together and orbit a common center of mass.
star cluster
A ___ is a galaxy undergoing a rapid burst of star formation.
starburst galaxy
The Hertzsprung-Russell (H-R) diagram can help you understand different kinds of ___.
stars
The Hertzsprung-Russell (H-R) diagram can help you understand different kinds of _____.
stars
As Earth continuously rotates on its axis, it revolves around the ________.
sun
The relatively dark spots on the sun that contains intense magnetic fields are called ___.
sunspots
A cluster of galaxy clusters.
superclusters
Clusters of galaxy clusters are known as ___.
superclusters
Exceptionally luminous star whose diameter is 100 to 1000 times that of the Sun.
supergiant star
In the context of general relativity, time slows down in curved space-time. This is referred to as ___
supernova
___ is the result of an explosion of a star.
supernova
In the context of the Jovian rings, moons:
supply the rings with particles.
The set of star types, called the spectral sequence, is important because it is a
temperature sequence
A scientific hypothesis must be _______.
testable
According to the inverse square relation, _____.
the flux you receive from a light source is inversely proportional to the square of the distance to the source
The magnifying power of a telescope equals:
the focal length of the primary mirror or lens divided by the focal length of the eyepiece.
weight
the force that gravity exerts on an object; changes with gravitational force
The heating of a planet or satellite because of friction caused by stretching due to the gravitational influence of a nearby body is referred to as ___.
tidal heating
The heating of a planet or satellite because of friction caused by stretching due to the gravitational influence of a nearby body is referred to as _____.
tidal heating
In the context of general relativity, time slows down in curved space-time. This is referred to as ___.
time dilation
If the orbit of the moon carries it through the umbra of Earth's shadow, you see a ____
total lunar eclipse
A lunar eclipse that occurs when the Moon moves completely into Earth's umbral shadow is called a ___.
total lunar elclipse
A period of total eclipse is known as ________.
totality
As the Moon grows fatter from new to full, it is said to wax.
true
Both reflecting and refracting telescopes may use a lens called the eyepiece.
true
In the Ptolemaic model Mercury and Venus had to be treated differently from the rest of the planets: their epicycles had to remain centered on the earth sun line. TRUE OR FALSE
true
Stars more massive than the Chandrasekhar limit can eventually end up as white dwarfs if they reduce their mass under the limit.
true
Venus is visible in the west after sunset or in the east before sunrise.
true
When an atom is in a magnetic field, the electron energy levels remain unaltered because the atom is limited to a single wavelength.
true
_____ is the event that occurs when the Moon passes directly between Earth and the Sun, blocking your view of the Sun.
A solar eclipse
Because of the scattering of light by dense clouds, the stars appear bluer than they should for their respective spectral types.
False
Brown dwarfs have high luminosities
False
Brown dwarfs have not been found in the halo of our Galaxy.
False
Claudius Ptolemy discovered that the orbit of Mars is an ellipse
False
Claudius Ptolemy discovered that the orbit of Mars is an ellipse.
False
Electrons in an atom are positively charged
False
Which of the following is true of johannes kepler?
He discovered that the orbit of Mars is an ellipse, not a circle
Which of the following is true of Johannes Kepler
He discovered that the orbit of mars is an eclipse, not a circle
In the context of Jupiter, which of the following statements is true of belt-zone circulation?
It results from Jupiter's rapid rotation
In the context of Jupiter, which of the following statements is true of belt-zone circulation?
It results from Jupiter's rapid rotation.
Which of the following is true of Uranus?
It rotates on its side with its equator almost perpendicular to its orbit.
If you see the crescent moon setting in the west what time of day is it?
Just after sunset
In astronomical usage, all atoms heavier than helium are referred to as__________.
Metals
A _____ is a meteor in space before it enters Earth's atmosphere.
Meteoroid
Neptune and Uranus appear a blue to blue-green color because of ___ in their atmospheres.
Methane
The photons of blue light have
More energy than the photons of red light
Revolution
Motion of a body around a point located outside a body
The twisting of the axis of rotation combined with the rotation of an object causes ___.
Precession
Small, powerful source of energy in the active core of a very distant galaxy.
Quasar
A _____ has a main mirror called the primary mirror
Reflecting telescope
In Keplers 3rd law the distance between the sun and a planet is equivalent to
The semi major axis of the planets orbit
Which of the following information is required to compute the mass of a galaxy using the rotation curve method?
The true sizes of the orbits of stars or gas clouds within the galaxy
In order to help answer important scientific questions, scientists will make observations and then ask questions about their observations.
True
In the Ptolemaic model, Mercury and Venus had to be treated differently from the rest of the planets. Their epicycles had to remain centered on the Earth-Sun line
True
In the Ptolemaic model, Mercury and Venus had to be treated differently from the rest of the planets: Their epicycles had to remain centered on the Earth-Sun line. (T or F)
True
Which of the following planets can be seen as a crescent from Earth? Saturn Jupiter Venus Mars
Venus
Which of the following planets is an example of a Terrestrial planet?
Venus
Which of the following planets' average density is closest to that of Earth?
Venus
_____ is an example of a planet. Rigel Venus Pluto Sirius
Venus
is an example of a planet
Venus
Galileo's observations of the complete set of the phases of Venus proved that:
Venus orbited the Sun
Galileo's observations of the complete set of the phases of Venus proved that: Earth orbited Venus. Venus orbited the Sun. the Moon orbited Venus. Venus orbited Earth.
Venus orbited the Sun.
The ___ marks the top of the sky above your head.
Zenith
semi-major axis, a
_____-_______ ______, __- Half of the longest diameter of an ellipse.
In the context of the evidence on evolution of stars, you can estimate the ___ of a star cluster by observing the distribution of the points that represent its stars in the Hertzsprung-Russell (H-R) diagram.
age
Kepler's Second Law
all planets move around earth in elliptical orbits
In its simplest form, the theory of Terrestrial protoplanet growth supposes that
all the planetesimals in each orbital zone had about the same chemical composition.
The Hubble time is:
an estimate of the age of the Universe based on the Hubble constant
apogee
an object in an elliptical orbit has its lowest velocity when it is farthest from Earth (___________) the point in an orbit most distant from the body being orbited; the highest point
Astronomers measure distances across the sky as
angles expressed in units of degrees and subdivisions of degrees
Astronomers measure distances across the sky as ____
angles expressed in units of degrees and subdivisions of degrees
Astronomers measure distances across the sky as _____. Correct Answer
angles expressed in units of degrees and subdivisions of degrees
At what critical temperature does the core of a star "light up"?
15 Million degrees Celsius
A full circle comprises ______ degrees.
360
Most recent studies suggest that the Sun is about ___ from the center of our Galaxy.
8.2 kiloparsecs
Most recent studies suggest that the Sun is about _____ from the center of our Galaxy.
8.2 kiloparsecs
The rotation of a body in which different parts of the body have different periods of rotation is called ___.
Differential rotation
Ancient philosophers and astronomers accepted without question—as first principles—that: heavenly objects must move in circular paths at varying speeds. the planets are made of rock and gas, much like Earth. the Earth is motionless at the center of the Universe. there are many galaxies in the Universe.
the Earth is motionless at the center of the Universe.
Absolute visual magnitude is the:
the apparent magnitude of a star observed from a distance of 10 pc.
Newton's third law
when one body exerts a force on a second body, the second body exerts an equal and opposite force back on the first
Observations and stellar evolution models indicate that the central star of a planetary nebula finally must contract and become a ___.
white dwarf
Active galaxy is a galaxy:
whose center emits large amounts of excess energy
The ___________ is the layer of the sun's atmosphere just above the photosphere.
chromosphere
One inaccuracy in the Copernican model was the belief that the planets move in uniform, ________ motions.
circular
the velocity needed to stay in a round orbit is called the ____
circular velocity
An interferometer consists of maximum of two telescopes connected to each other.
false
Because of the scattering of light by dense clouds, the stars appear bluer than they should for their respective spectral types.
false
Carbonaceous chondrites are a class of iron meteorites.
false
Earth is an example of a jovian planet
false
When a star has exhausted all of its hydrogen, it is said to have reached the zero-age main sequence (ZAMS).
false
Widmanstätten patterns are mostly seen in stony meteorites.
false
Y dwarfs are substellar objects with temperature above 500 K.
false
The brightest stars are categorized as the ___________ stars.
first-magnitude
Which of the following is a Kuiper Belt Object that is quite large and has about the same diameter as Pluto but is 27% more massive?
eris
One of the main causes of slow surface evolution is the:
erosion due to moving air and water.
By tradition, any planet in the sunset sky is called a(n)
evening star
By tradition, any planet in the sunset sky is called a(n) ___.
evening star
By tradition, any planet in the sunset sky is called a(n) _____.
evening star
In the context of Schwarzschild black holes, the ___ is the boundary between the isolated volume of space-time and the rest of the Universe.
event horizon
In the context of Schwarzschild black holes, the _____ is the boundary between the isolated volume of space-time and the rest of the Universe.
event horizon
What phase is the Moon during a Lunar Eclipse?
full moon
A(n) ___ is a model universe with Earth at the center, such as the Ptolemaic Universe.
geocentric
One observation that supported the __________ theory was that the stars, sun, and planets appear to "revolve" around Earth each day.
geocentric
What type of universe did Aristotle devise?
geocentric
A(n) ____ is a model universe with earth at the center such as the ptolemaic universe
geocentric universe
__________is an example of a Jovian planet.
jupiter
Mars's atmosphere has reduced because of the _____.
lack of an ozone layer in Mars
The total amount of energy a star radiates per second at all wavelengths.
luminosity
The least important power of a telescope is ___.
magnifying power
Astronomers measure the brightness of stars using the ________ scale.
magnitude
Scale used to describe the brightness of stars.
magnitude
The dark gray areas of the Moon visible from Earth are called ___.
maria
The ___ of an objects is a measure of the amount of matter in the object.
mass
The _____ of an object is a measure of the amount of matter in the object. velocity weight height mass
mass
The time a protostar takes to contract from a cool interstellar gas cloud to a main-sequence star depends on its ___.
mass
The time a protostar takes to contract from a cool interstellar gas cloud to a main-sequence star depends on its _____.
mass
The more massive a main-sequence star is, the more luminous it is.
mass-luminosity relationship
Which Terrestrial planet(s) do not have an atmosphere?
mercury
Which of the following planets has the highest uncompressed density?
mercury
Massive stars:
Die after only a few million years
Very massive stars
Die after only a few million years
The Local Group is a ___.
poor galaxy cluster
Evening Star
Any planet visible in the evening sky.
Morning Star
Any planet visible in the sky shorty before sunrise.
Absolute magnitude is...
Apparent magnitude of a star observed from a distance of 10pc
Which of the following is a similarity between the cloud layers on Saturn and the cloud layers on Jupiter?
Both form at the same temperature
Which of the following are hypotheses for the formation of the Milky Way Galaxy?
Bottom-up galaxy formation Monolithic collapse Top-down galaxy formation
According to the solar nebula theory, dust grains, whatever their composition, grew from microscopic size first by _____.
Condensation
___ say that certain things cannot be created out of nothing or vanish into nothing.
Conservation Laws
A grouping of stars in the night sky that is named after a mythical god, animal, or other object.
Constellation
If you move an electron from a lower energy level to a higher energy level, you can call the atom a(n) _____.
Excited Atom
propose, explanation, hypothesis, observation, experimentation, theory, description, applicable, evidence, natural law, fundamental principles, confidence,
HOW DO WE KNOW? HYPOTHESIS, THEORY, AND LAW Why is a theory much more than just a guess? Scientists study nature by devising and testing new hypotheses and then developing the successful ideas into theories and laws that describe how nature works. A good example is the connection between sour milk and the spread of disease. A scientist's first step in solving a natural mystery is to ________ a reasonable __________ based on what is known so far. This proposal, called a ________, is an assertion or statement that must be tested through _________ and ___________. From the time of Aristotle, philosophers believed that food spoils as a result of the spontaneous generation of life—for example, mold growing out of drying bread. French chemist Louis Pasteur (1822-1895) hypothesized that microorganisms were not spontaneously generated but were carried through the air. To test his hypothesis he sealed an uncontaminated nutrient broth in glass, completely protecting it from the microorganisms on dust particles in the air. No mold grew, effectively disproving spontaneous generation. Although others had argued against spontaneous generation before Pasteur, it was Pasteur's meticulous testing of his hypothesis by experiment that finally convinced the scientific community. A ________ generalizes the specific results of well-confirmed hypotheses to give a broader _________ of nature, which can be applied to a wide variety of circumstances. For instance, Pasteur's specific hypothesis about mold growing in broth contributed to a broader theory that disease is caused by microorganisms transmitted from sick people to well people. This theory, called the germ theory of disease, is a cornerstone of modern medicine. It is a common misconception that the word theory means a tentative idea, a guess. As you can see, scientists actually use the word theory to mean an idea that is widely _________ and confirmed by abundant __________. Sometimes, when a theory has been refined, tested, and confirmed so often that scientists have great confidence in it, it is called a __________ _______. Natural laws are the most __________ __________of scientific knowledge. Kepler's laws of planetary motion are good examples. Confidence is the key. In general, scientists have more __________ in a theory than in a hypothesis and the most confidence in a natural law. However, there is no precise distinction among hypotheses, theories, and laws, so use of these terms is sometimes a matter of tradition. For instance, some textbooks refer to the Copernican "theory" of heliocentrism, but it had not been well tested when Copernicus proposed it, and it is more rightly called the Copernican hypothesis. At the other extreme, Darwin's "theory" of evolution, containing many hypotheses that have been tested and confirmed over and over for nearly 150 years, might more correctly be called a natural law.
Emission nebulae are also called _____.
H II regions
Increasing the diameter of a telescope
Increases its light gathering power
In a binary system, the most massive star:
Is closer to the center of mass
A starburst galaxy is a galaxy that
Is undergoing a rapid surge of star formation
Which of the following statement is true of the solar wind?
It can be considered an extension of the corona
Who was Tycho Brahe's assistant?
Johannes Kepler
Which Jovian planet has the greatest magnetic field?
Jupiter
Which of the following is the largest of the Jovian planets?
Jupiter
One of the factors that escape velocity depends on is the:
Mass of the celestial body
Horoscope
Shows location of the sun, moon, and planets among zodiacal signs
Both reflecting and refracting telescopes may use a lens called the eyepiece
True
Copernicus proposed that Earth rotates on its axis daily as it revolves around the sun once a year.
True
Earth's motion around the sun in its orbit defines a year.
True
Earth's rotation produces day and night.
True
Emission nebulae are produced when a hot star excites the gas near it to produce an emission spectrum.
True
Herbig-Haro objects are extra solar planets.
True
In astronomy, the metric system is used to make measurements.
True
Which if the following planets can be seen as a crescent from Earth?
Venus
Only photons with wavelengths _____ can ionize hydrogen.
shorter than 91.2 nm
The __________ month is the period of revolution of the moon to around Earth with respect to the stars.
sidereal
An atmosphere containing enough greenhouse gases can trap heat and raise the temperature of a planet's surface
true
The Sun crosses the celestial equator going northward at the point called the _____.
vernal equinox
A binary star system in which the two stars are separately visible in the telescope.
visual binary
The Elysium region is a ___.
volcanic plain on mars
Spiral galaxies usually contain:
young stars
The band on the H-R diagram where stars begin their stable lives fusing hydrogen.
zero-age main sequence
___ The location in the H-R diagram where stars first reach stability as hydrogen-burning stars.
zero-age main sequence
The oldest Earth rocks so far discovered and dated are ___.
zircon crystals
The ___ is a band centered on the ecliptic and encircling the sky.
zodiac
Tycho Brahe contributions
-1572 new star appeared in sky = couldn't detect its parallax, said it must be further then the moon -tracked motion of planets without telescope using many instruments -model retained first principles = geocentric with sun and moon revolving around earth, other planets around sun, circular motion
describe motion of a body in orbit
-an object orbiting earth is actually falling (being accelerated) toward earth's center, horizontal velocity prevents collision -object in elliptical orbit has lowest velocity farthest from object (apogee) and highest closest (perigee)
retrograde motion
-backwards/westward motion
difference of action reaction pairs and net force
-blowing up a balloon example = expands because net force is not zero, forces still equal -action reaction pairs don't tell about motion
The difference of closed and open orbits
-closed = repeating cycles, ex: moon around earth -open = requires escape velocity, velocity needed to leave orbit, does not return to object orbited -with escape velocity = follows parabola -higher than escape velocity = follows hyperbola
relation of force, mass, and acceleration
-f = ma something massive and slow can have great force = planet something small and fast can have great force = bullet
How tides affect orbits and rotation
-friction gradually slowing earths rotation, tidal bulges on moon have slowed it and it now keeps same side facing earth -also affects orbits = rotation of earth drags tidal bulges slightly ahead of moon, gravitation of bulges of water pull moon forward = moons orbit grows by 4 cm a year
inertia
-in newton's first law -tendency of object to resist change -more mass = more inertia
What is your latitude if the north celestial pole appears on your horizon?
0°
How old are the stars in the Pleiades constellation?
100 Million years old
What is the ratio of the light gathering power of a telescope with the primary lens of diameter 10 m to a telescope with a primary lens of diameter 1 m
100 to 1
What is the ratio of the light-gathering power of a telescope with a primary lens of diameter 10 m to a telescope with a primary lens of diameter 1 m? 100 to 1 1 to 10 10 to 1 1 to 100
100 to 1
The seasons will alternate every _______ years between the Northern and Southern hemispheres.
13,000
The Andromeda Galaxy has a look-back time of:
2 million years
The precession of Earth's axis takes about ___ for one cycle.
26,000 years
The precession of Earth's axis takes about _____ for one cycle. 12,000 years 30,000 years 10,000 years 26,000 years
26,000 years
The precession of the earth's axis takes about ___ for one cycle.
26,000 years
Except Mercury's orbit, the rest of the planets' orbital planes are inclined by no more than _____.
3.4 degrees
planetary motion
3-3 TYCHO BRAHE, JOHANNES KEPLER, AND PLANETARY MOTION As astronomers struggled to understand the place of Earth, they also faced the problem of ___________ __________. How exactly do the planets move? That problem was solved by a nobleman who built a fabulous observatory and a poor commoner with a talent for mathematics.
tides, universal, differences, gravitational force, side, closer, pulls, deeper, two high, moon, sun, rotation, orbital motion
3-5c Tides: Gravity in Action Newton understood that gravity is mutual—Earth attracts the Moon, and the Moon attracts Earth—and that means the moon's gravity can explain the ocean ________. But Newton also realized that gravitation is ___________, and that means there is much more to tides than just Earth's oceans. Tides are caused by small ____________________ in ________________ ___________. As Earth and the Moon orbit around each other, they attract each other gravitationally. Because the ________ of Earth toward the Moon is a bit ___________, the Moon ___________ on it more strongly and that pulls up a bulge. Also, the Moon pulls on Earth a bit more than it pulls on Earth's far side and that produces a bulge on the far side (Figure 3-12). The oceans are ____________ in these bulges, and as Earth rotates and carries you into a bulge, you see the tide creeping up the beach. Because there are two bulges, there are _____ _____ tides each day, although the exact pattern of tides at any given locality depends on details such as ocean currents, the shape of the shore, and so forth. (Moon's gravity pulls moreon the near side thanthefar side (NPand SP)) (Tides are produced by small differences in the gravitational force exerted on different parts of an object. The side of Earth nearest the Moon feels a larger force than the side farthest away. Relative to Earth's center, small forces are left over, and they cause the tides. Both the _______ and the __________ produce tides on Earth. Tides can alter both an object's ______________ and __________ __________.)
A megaparsec (Mpc) is equal to ___.
3.3 million ly
A megaparsec (Mpc) is equal to _____.
3.3 million ly
The avg bright star in our sky is *** ly away
300
You can see **** stars with the naked eye
3000
Earth circles the Sun in
365.26 days
Earth circles the Sun in ___.
365.26 days
Earth circles the Sun in _____.
365.26 days
Earth circles the sun in ____
365.26 days
Mathematical Syntaxis, almagest, mercury, venus, Earth-Sun, telescope
3a Ptolemy's great book _______________ _____________ (about the year 140) contained the details of his model. Islamic astronomers preserved and studied the book through the Middle Ages, and they called it Al Majisti (The Greatest). When the book was found and translated from Arabic to Latin in the 12th century, it became known as _____________. 3b The Ptolemaic model of the Universe shown below was geocentric and based on uniform circular motion. Note that ___________ and ___________ were treated differently from the rest of the planets. The centers of the epicycles of Mercury and Venus had to remain on the ________-________ line as the Sun circled Earth through the year. Equants and smaller epicycles are not shown here. Some versions contained nearly 100 epicycles as generations of astronomers tried to fine-tune the model to better reproduce the motion of the planets. Notice that this modern illustration shows rings around Saturn and sunlight illuminating the globes of the planets, features that could not be known before the invention of the ______________.
Sagittarius A* has a mass of ___.
4 million solar masses
Sagittarius A* has a mass of _____.
4 million solar masses
when written in scientific notation 42,300,000,000 is equal to
4.23 x 1010
The radioactive age of the moon rocks show that the Moon's surface solidified about ___.
4.4 billion years ago
The Moon must be at least ___ years old.
4.48 billion
Our Sun and its planets were formed about
4.6 Billion years ago
The moon's diameter is _______ times smaller than the sun's.
400
The shortest wavelength of visible light is ___.
400 nanometers
The pointer stars are * degrees apart
5
The Kuiper Belt is located just beyond Neptune out to ___.
50 AU or more
The Kuiper Belt is located just beyond Neptune out to _____.
50 AU or more
There are how many arc minutes in 1 degree?
60
The Sun rotates with its equator inclined ___ to Earth's orbit.
7.2
The longest wavelength of visible light is ___.
700 nanometers
The longest wavelength of visible light is _____. 400 nanometers 900 nanometers 500 nanometers 700 nanometers
700 nanometers Correct. The longest wavelength of visible light is 700 nanometers (nm). The wavelength of visible light ranges between about 400 nm and 700 nm, or, equivalently, 4000 angstroms (Å) and 7000 angstroms (Å)
Approximately how long does it take light to reach the Earth from the Sun?
8 minutes
Light from the Sun reaches Earth in about_______
8 minutes
The look-back time to the Sun is ___.
8 minutes
The look-back time to the Sun is _____.
8 minutes
As per the turnoff point in the cluster H-R diagram, the oldest open clusters in the Milky Way have ages of about ___.
9-10 billion years
A star remains on the main sequence for a time span equal to _____ of its total existence as an energy-generating star.
90 percent
A star remains on the main sequence for a time span equal to _____ of it's total existence as an energy generating star
90%
A star remains on the main sequence for a time span equal to _____ of its total existence as an energy-generating star.
90%
Newton concluded that a force from the earth had to act on the moon because
A force is needed to change the direction of the moons motion
What is the elysium region?
A volcanic plain on mars.
The centers of active galaxies that are emitting large amounts of excess energy.
Active Galactic Nuclei
The centers of active galaxies that are emitting large amounts of excess energy are called ___.
Active galactic nucleus
Luminosity
Actual brightness of a star
In the context of the evidence on evolution of stars, you can estimate the _____ of a star cluster by observing the distribution of the points that represent its stars in the Hertzsprung-Russell (H-R) diagram
Age
saros cycle
An 18 year old 11 1/3 day period after which the pattern of lunar and solar eclipses repeats
The Hubble time is:
An estimate of the age of the Universe based on the Hubble constant.
To _____ is to make observations of reference objects, checks on instrument performance, and calculations of units conversations, needed to completely understand measurement of unknown quantities.
Calibrate
144, renaissance, Copernican Revolution, Isaac Newton
Chapter 3-5 ISAAC NEWTON, GRAVITY, AND ORBITS The birth of modern astronomy and of modern science dates from the _____ years between the publication of Copernicus's and Newton's chief works (in 1543 and 1687 respectively). The ____________ is commonly taken to be the period approximately between 1350 and 1600, so the 144 years of this story lie at the climax of the European reawakening of learning in all fields (Figure 3-11). >The five astronomers of this story lived at the culmination of the Renaissance: Coperinicus, Tycho Brahe (Tycho's nova- 1572), Galileo (Sidereal messenger- 1610 and Dialogues- 1632), Kepler (Law I and II- 1609 and Law III 1609), Newton (Prinicipia- 1687) telescope invented 1608 The problem of the place of Earth was resolved by the ________ _______, but the problem of planetary motion was only partly solved by Kepler's laws. For the last 10 years of his life, Galileo studied the nature of motion, especially the accelerated motion of falling bodies. Although he made some important progress, he was not able to relate his discoveries about motion to the heavens. That final step was taken by ______ __________.
A ______ is an electronic device consisting of a large array of light sensitive elements used to record very faint images
Charge-couples device
Which of the following is a relatively large moon of Pluto?
Charon
The magnitude scale dates all the way back to the time of __________ in 140 AD and earlier with Hipparchus in 190-120 BC.
Claudius Ptolemy
If there were lots of baryons present during the early moments of the big bang, they would have:
Collided with each other to form deuterium
___ are circular bulges on Venus up to 1600 mi in diameter bordered by fractures, volcanoes, and lava flows.
Coronae
A _____ is a telescope designed to capture images of faint objects such as the corona of the Sun that are near relatively bright objects
Coronagraph
identify a true statement about the sun. A. it is the smallest star in the universe B. it is at a distance of 2 A from earth C. it shines by reflecting light from the moon D. It generates its own energy
D. it generates its own energy
Diurnal motion
Daily rotation of the sky
_____ is the energy believed to fill empty spaces and drive the acceleration of the expanding Universe
Dark Energy
Most of the mass of a galaxy is contained in the
Dark matter of the galaxy
___ is mass per volume.
Density
The ___ is an apparent change in the wavelength of radiation caused by relative motion of a source and observer.
Doppler Effect
The change in wavelength of radiation due to relative radial motion of source and observer is called ___.
Doppler Effect
On the autumnal equinox the sun rises
Due east
The process by which a rotating, convecting body of conducting matter, such as in Earth's core or in the Sun's convection zone, can generate a magnetic field is referred to as the _____.
Dynamo Effect
Who gave us the general theory of relativity?
Einstein
The presence of _____ on the Moon implies that the craters on the Moon were formed by impacts
Ejecta
___ is pulverized rock scattered by meteorite impacts on a planetary surface.
Ejecta
_____ is pulverized rock scattered by meteorite impacts on a planetary surface
Ejecta
Johannes Kepler discovered that the orbits of the planets were not circular. What shape are they?
Ellipses
All planets circular motion
Farther from the sun=slower movement.
A lunar eclipse can only occur if the moon is
Full
A(n) ___ is one in which an object orbiting Earth has an orbital period equal to the rotation period of Earth.
Geosynchronous orbit
Uranometria
Give the greek letter followed by the possessive form of the constellation name.
__________is the gradual increase in the surface temperature of Earth caused by human modifications to Earth's atmosphere.
Global Warming
Which of the following is true of the star clusters in the Milky Way?
Globular clusters are much too far away to have measurable parallaxes
Celestial equator
Halfway between the celestial points
Europa's visible surface:
Has long cracks in its icy crust
Mercury is geologically inactive because it:
Has lost much of its internal heat
Which of the following is true of Galileo Galilei?
He applied his careful observations of the sky to determine the place of Earth.
WHich of the following is true of galileo galilei?
He applied his careful observations of the sky to determine the place of the earth.
In the context of a star's spectrum, which of the following statements is true of a giant star?
Hydrogen atoms in its atmosphere do not often collide with each other
In stellar astronomy, ___ states that the weight of each layer of a star must be supported by the layer below
Hydrostatic equilibrium
The main reason for connecting two or more telescopes in an interferometer is to
Improving resolving power
How do astronomers measure distance across the sky?
In angles expressed in units of degrees and subdivision of degrees
Spectra are often represented as graphs of
Intensity vs wavelength
Identify a true statement about the Sun. -It is the smallest star in the universe -It is at a distance of 2 AU from Earth. -It generates it own energy -It shines by reflecting light from the Moon.
It generates its own energy
Which of the following statements is true of Uranus?
It has a deep mantle of partly solid water.
Which of the following is true of Mars?
It has a heavily cratered crust marked by volcanoes.
Which of the following is true of Earth's interior?
It has a low-density crust.
Which of the following is true of a closed Universe?
It has a positive curvature
Which of the following statements is true of Nereid, Neptune's moon?
It takes about an earth year to circle neptune once.
A temperature scale using Celsius degrees and based on zero being equal to absolute zero.
Kelvin
The least important power of a telescope is _____.
Magnifying power
Zenith
Marks the top of the sky above your head
___ is an example of a Terrestrial planet.
Mars
What occurs when the Moon is in the first or third quarter of its lunar cycle?
Neap Tides
___ occur when the Moon is in the first or third quarter of its lunar cycle..
Neap tides
____ occur when the moon is first or third quarter of its lunar cycle
Neap tides
____ occur when the moon is the first or third quarter of its lunar cycle
Neap tides
___ is a relatively dense cloud of interstellar gas and dust.
Nebula
straight, acted upon, force, change, force, direction, equal, opposite
Newton's Three Laws of Motion 1) A body continues at rest or in uniform motion in a ________ line unless _____ ____ by some _____. (inertia) 2) A body's ______ of motion is proportional to the ______ acting on it, and is in the ________ of the force. 3) When one body exerts a force on a second body, the second body exerts an ______ and __________ force back on the first body.
Which of the following metals is a constituent of iron meteorites?
Nickel
Who is the father of modern astronomy?
Nicolaus Copernicus
___ was the first person to produce a detailed heliocentric model of the Universe with substantial justifying arguments.
Nicolaus Copernicus
____________ wrote an essay proposing a heliocentric model in which the sun was at the center of the universe.
Nicolaus Copernicus
Reactions that join the nuclei of atoms to form more massive nuclei
Nuclear Fusion
Which of the following statements is true of the evolution of massive stars?
Once the gas in the core of a massive star has been converted to iron, there are no further nuclear reactions that can release energy.
Constellation
One of the stellar patterns identified by name, usually of mythological gods, people, animals, or objects. Also, the region of the sky containing that star pattern.
Which of the following is true of the star clusters in the Milky Way
Open clusters are concentrated along the disk of the Milky Way.
Kepler's third law of planetary motion states that....
Orbital period and semi-major axis are related.
A _______ is a commonly accepted set of scientific ideas and assumptions
Paradigm
The true distance of a nearby object can be calculated from the size of the apparent shift in its position relative to the background as seen from two viewing positions. That shift is called ___.
Parallax
___ is the apparent motion of an object because of the motion of the observer.
Parallax
During a solar eclipse, if you moved into the _____ you would be in partial shadow wand would also see part of the sun peeking around the edge of the moon?
Penumbra
During a solar eclipse, if you moved into the__________, you would be in partial shadow and would also see part of the Sun peeking around the edge of the Moon. penumbra south point north point umbra
Penumbra
The _____ of a star is the time it takes the star to complete a cycle from bright to faint to bright again
Period of pulsation
The _____ of the sun is visible during an annular eclipse
Photosphere
Kuiper Belt Objects that are caught in a 3:2 orbital resonance with Neptune are referred to as ___.
Plutinos
Which of the following is a prototype of a new class of objects defined by the International Astronomical Union (IAU) as dwarf planets?
Pluto
In a Hertzsprung-Russell (H-R) diagram, a star is represented by a _____ on the graph that tells you its luminosity and temperature.
Point
__________is a possible form of dark energy that can change in strength as the Universe ages.
Quintessence
__________is that component of an object's velocity that is directed away from or toward an observer.
Radial velocity
The center of the Milky Way is in ___.
Sagittarius
The powerful radio source located at the core of the Milky Way Galaxy.
Sagittarius A*
A method for expressing very large or very small numbers by using powers of 10.
Scientific Notation
______ Is a method for expressing very large or very small numbers by using powers of 10
Scientific notation
The sharp outer edges of rings are confined by ___ that gravitationally usher straying particles back into the rings.
Shepard Satellites
Which of the following has been established through helioseismology observations?
The Sun's magnetic field is generated by the dynamo effect at the bottom of the convection zone deep under the photosphere.
Ecliptic
The apparent path of the sun in its yearly motion
Which of the following lies halfway between the celestial poles?
The celestial equator
More than 2000 years ago, Hipparchus compared the positions of some stars with their positions recorded nearly two centuries previously and realized that:
The celestial poles and equators were slowly moving across the sky
Which of the following was the most perfect region according to Aristotle's philosophy?
The heavens
Which of the following was the most perfect region according to Aristotle's philosophy? The center of the Sun Earth's center The heavens Earth's surface
The heavens
Precession
The slow change in the direction of Earth's axis of rotation; one cycle takes nearly 26,000 yrs.
Aphilon
The sun's most distant point from the sun
Which of the following statements is true of the analysis called helioseismology?
The vibrations in the Sun are used by solar astronomers to explore its depths
Which of the following statements is true of the analysis called helioseismology?
The vibrations in the Sun are used by solar astronomers to explore its depths.
Which of the following is a result of Earth revolving around the Sun?
The yearly cycle
What do all stars on the main sequence have in common?
They are all burning hydrogen into helium in their cores
Which of the following statements is true of brown dwarfs?
They are almost the same size as Jupiter.
Which of the following is true of the scientific names of constellations?
They are in Latin or Greek.
Which of the following is true of spring tides?
They occur at new moon and full moon
Which of the following is true of spring tides? They occur at dawn and dusk every day. They occur at noon and midnight every day. They occur at new moon and full moon. They occur at first- and third-quarter moons.
They occur at new moon and full moon.
Which of the following is true of rich galaxy clusters?
They often contain one or more giant elliptical galaxies at their centers
As the moon grows fatter from new to full, it is said to wax t or f
True
Astronomers think of pulsars not as pulsing objects but rather as objects emitting beams
True
___, the largest of Saturn's moons, has an atmosphere composed mostly of nitrogen with traces of argon and methane.
Titan
4. Spiral arms help in star formation
True
In the context of nuclear fusion in massive stars, hydrogen fusion can last 7 million years in a 25-solar-mass star, but that same star will fuse its oxygen in six months and its silicon in just one day.
True
Issac Newton guessed that gravity works by an inverse square relation because he had already discovered that light behaves this way
True
It is a common misconception that sunlight during an eclipse is extra dangerous.
True
LIght pollution makes it impossible to see faint objects
True
Light from Proxima Centauri takes 4.2 years to reach the earth. TRUE OR FALSE
True
Greenhouse gases are opaque to ___.
UNKNOWN
Reionization
Ultraviolet photons from the first stars ionized the gas of the universe
Which of the following is a difference between low-mass stars and medium-mass stars?
Unlike medium-mass stars, low-mass stars cannot become giant stars.
In the context of the discovery of Neptune, the existence and location of Neptune were calculated from irregularities in the motion of ___.
Uranus
In the context of the discovery of Neptune, the existence and location of Neptune were calculated from irregularities in the motion of _____.
Uranus
Contellations
Used across many cultures, defferent names some may be oldest surviving traces of human culture.
The Sun crosses the celestial equator going northward at the point called the
Vernal Equinox
The Sun crosses the celestial equator going northward at the point called the _____. summer solstice winter solstice autumnal equinox vernal equinox
Vernal equinox
Which of the following sequences of electromagnetic radiation is arranged in the order of increasing energy?
Visible light, ultraviolet radiation, X-rays, and gamma rays
The largest fully steerable radio telescope is in ___.
West Virginia
According to astronomers, the Milky Way is _____.
Wheel-shaped
epicycle
______________- The small circle followed by a planet in the Ptolemaic theory. The center of the epicycle follows a larger circle (the deferent) around Earth.
paradigm
________________- A commonly accepted set of scientific ideas and assumptions.
geosynchronous satellite
_________________ _______________- A satellite that orbits eastward around Earth with a period of 24 hours and remains above the same spot on Earth's surface.
Sometimes when a theory has been refined, tested, and confirmed so often that scientists have great confidence in it it is called ?
a natural law
Sometimes, when a theory has been refined, tested, and confirmed so often that scientists have great confidence in it is called _____
a natural law
Sometimes, when a theory has been refined, tested, and confirmed so often that scientists have great confidence in it, it is called_________
a natural law
This type of lunar eclipse occurs when the moon stays in the penumbra and never reaches the umbra.
a penumbral lunar eclipse
Kepler's second law of planetary motion states that:
a planet moves at its greatest speed when it is closest to the Sun.
22. Which of the following stars is a part of the Solar System?
a. The Sun
What is a rotating disk that forms as matter is drawn gravitationally toward a central body?
accretion disc
39. The average distance from Earth to the Sun is called the__________.
a. astronomical unit
Star brightnesses expressed in the magnitude system are known as _____, describing how the stars look to human eyes observing from Earth.
apparent visual magnitudes
Astronomers express angular measurements as all of the following except:
arc percentages
An ________ is a small unit of angular measurement represented as 1/3,600 of a degree.
arc second
Red dwarfs:
are cool and small with low luminosities.
The _____________ unit is used to measure the distance from Earth to the sun.
astronomical
The average distance from Earth to the sun is called the ________
astronomical unit
The average distance from earth to the sun is called the
astronomical unit
Jupiter's extensive magnetosphere is responsible for _____ around the magnetic poles.
aurorae
The eerie and pretty northern and southern lights that are produced when gases in Earth's upper atmosphere glow from energy delivered by the solar wind are referred to as _____.
aurorae
The Sun is on the celestial equator during the:
autumnal equinox and the vernal equinox
53. __________is a unit of distance equal to the distance light travels in 1 year.
b. The light-year
The ___ is the high-density, high-temperature state from which the expanding Universe of galaxies began.
big bang
The fate of the Universe if dark energy increases with time and everything is eventually torn apart, down to the atomic level, by the accelerating expansion of the Universe.
big rip
Which of the following is left behind when a star dies?
black hole
In the context of electromagnetic radiation, the radiation emitted by an opaque objects is called ___.
blackbody radiation
___ is the radiation emitted by an opaque object.
blackbody radiation
A galaxy is made of all of the following except:
bodies of water
49. __________is the hazy band of light that circles our sky, produced by the glow of our Galaxy.
c. The Milky Way
14. _____ is an example of a planet.
c. Venus
16. A light-year is a unit of _____.
c. distance
18. Nathan observes an image that shows a park about 100 meters across occupied by few children and trees. The area visible to Nathan is called _____.
c. the field of view
According to the solar nebula theory, dust grains, whatever their composition, grew from microscopic size first by ___.
condensation
The ___ is radiation from the hot matter of the Universe soon after the big bang.
cosmic microwave background
___ is a constant in Einstein's equations of space and time that represents a force of repulsion.
cosmological constant
The assumption that any observer in any galaxy sees the same general features of the Universe.
cosmological principle
The second stage of planetary evolution is ___.
cratering and giant basin formation
The average density of the Universe needed to make its curvature flat.
critical density
A totally eclipsed moon glows coppery red because a. the moon' surface is made of iron ore which is red in color. b. red light is cooler than blue light. c. during a lunar eclipse the sun is cooler than normal, and its light is more red. d. red light is better able to pass completely through Earth's atmosphere and reach the moon. e. The moon appears red during a total solar eclipse, not a total lunar eclipse.
d
The rotation of a body in which different parts of the body have different periods of rotation is referred to as ___.
differential rotation
The rotation of a body in which different parts of the body have different periods of rotation is referred to as _____.
differential rotation
For an observer at 30° N latitude, what is the maximum angle between the observer's southern horizon up to the moon? a. 30° b. 53.5° c. 58.5° d. 83.5° e. 88.5°
e
The synodic period of the moon is a complete cycle of lunar phases. Takes 29.5 days. a. is about 27.32 days long. b. is the period of time for the moon to orbit Earth once with respect to the stars. c. is the period of time between successive eclipses at a given location on Earth. d. is the period of time from when the moon rises until the moon rises again the next night. e. none of the above
e
The time for the moon to repeat its cycle of phases is equal to a. its sidereal period. b. one day. c. one hour. d. one year. e. its synodic period.
e
___ is an example of a Terrestrial planet.
earth
_he Sun fuses ___ hydrogen nuclei to makes one helium nucleus.
four
One of the reasons that gold is a rare element is that:
gold atoms are made only by short-lived nuclear reactions.
The fine structure of bright grains with dark edges covering the Sun's surface are called ___.
granulation
A galaxy is held together by _______.
gravity
Europa's visible surface:
has long cracks in its icy crust.
Neptune may have more atmospheric activity than Uranus because it:
has more heat flowing out of its interior.
Simple physics predicts that neutron stars should:
have strong magnetic fields
Energy contained in matter in the form of agitation of its particles.
heat
A(n) ___ is a model of the Universe with the Sun at the center, such as the Copernican universe.
heliocentric
In astronomical usage, metals are all atoms heavier than _________.
helium
The ignition of helium in the core of a star changes the structure of the star. The star now makes energy in two locations by two different processes, _____.
helium fusion in the core and hydrogen fusion in the surrounding shell
Which of the following is true of carbonaceous chondrites?
hey contain materials left over from the formation of the Solar System.
A tentative explanation.
hypothesis
If a hypothesis is _________, the question should not be thrown out.
incorrect
Increasing the diameter of a reflecting telescope: decreases its magnifying power. increases its chromatic aberration. increases its light-gathering power. decreases its resolving power.
increases its light-gathering power
Increasing the diameter of a reflecting telescope:
increases its light-gathering power.
Greenhouse gases are opaque to _____.
infrared radiation
___ is the region of the H-R diagram in which stars are unstable to pulsation.
instability strip
The process in which dust scatters blue light out of starlight, making the stars look redder
interstellar reddening
___ is the process in which dust scatters blue light out of starlight and makes the stars look redder
interstellar reddening
A measure of the amount of light a star produces is called ___.
intrinsic brightness
The process in which atoms lose or gain electrons is referred to as ___.
ionization
The energy of a photon:
is inversely proportional to the wavelength of the light
The energy of a photon:
is inversely proportional to the wavelength of the light.
The energy of a photon: is inversely proportional to the wavelength of the light. depends only on the speed of the light. is inversely proportional to the frequency of the light. depends only on the mass of the photon.
is inversely proportional to the wavelength of the light. Correct. The amount of energy a photon carries depends on its wavelength. Shorter-wavelength photons carry more energy, and longer-wavelength photons carry less energy.
The Milky Way:
is larger than most other galaxies
A starburst galaxy is a galaxy that:
is undergoing a rapid surge of star formation
A(n)__________is a form of an atom with the same number of protons but a different number of neutrons. meteor isotope ion molecule
isotope
The observation that, in its general properties, the Universe looks the same in every direction.
isotropy
Which of the following statements is true of the chromosphere?
it can be seen during a solar eclipse
Nanometer is a unit of ___.
length
A ___ is a meteor in space before it enters Earth's atmosphere.
meteoroid
The Roche limit is the:
minimum distance between a planet and a satellite that can hold itself together by its own gravity.
What is the roche limit?
minimum distance between a planet and a satellite that can hold itself together by its own gravity.
geocentric model
model universe with earth at center: ptolemy's model
During _______ of the year, the sun shines more directly on the Northern Hemisphere.
one-half
A(n) _____ is a sensitive astronomical instrument that measures the brightness of individual objects very precisely. photometer array detector grating charge-coupled device
photometer Correct. A photometer is a sensitive astronomical instrument that measures the brightness of individual objects very precisely.
A__________is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength.
photon
A _____ is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength. wave fringe photon grating
photon Correct. A photon is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength. A particle of light is called a photon, and you can think of a photon as a minimum-sized bundle of electromagnetic waves.
The __________ of the sun is not visible during a total solar eclipse.
photosphere
The bright, apparent surface of the Sun is called the ___.
photosphere
________ are spherical, non-luminous bodies that orbit a star.
planets
Earth's axis would remain pointed constantly toward a spot near the star Polaris except for the effect of _____
precession
___ are massive objects destined to become planets.
protoplanets
In the context of the excitation of atoms, jumps of electrons from one orbit to another are sometimes called__________. filtered jumps quantum jumps magnetic jumps transitional jumps
quantum jumps
The study of the behavior of atoms and atomic particles is referred to as:
quantum mechanics
The study of the behavior of atoms and atomic particles is referred to as: theory of computations. quantum mechanics. the electromagnetic theory. thermodynamics.
quantum mechanics.
Radio telescope have poor resolving power because
radio waves have long wavelengths
_________is one of the Jovian planets.
saturn
magnitude scale
scale by which star brightness is measured
The magnifying power of a telescope equals: the diameter of the primary lens or mirror of the telescope. the focal length of the eyepiece divided by the focal length of the objective of the telescope. the focal length of the primary mirror or lens divided by the focal length of the eyepiece. the diameter of the eyepiece of the telescope.
the focal length of the primary mirror or lens divided by the focal length of the eyepiece. Correct. The magnifying power of a telescope equals the focal length of the primary mirror or lens divided by the focal length of the eyepiece. For example, a telescope with a primary mirror that has a focal length of 700 mm and an eyepiece with a focal length of 14 mm has a magnifying power of 50.
According to Wein's law
the hotter an object is, the shorter is the wavelength of its maximum intensity
According to Wien's law, _____. the hotter an object is, the shorter is the wavelength of its maximum intensity the cooler an object is, the shorter is the wavelength of its maximum intensity hotter objects emit less energy than cooler objects of the same size cooler objects emit more energy than hotter objects when the size of the objects are different
the hotter an object is, the shorter is the wavelength of its maximum intensity
In stellar astronomy, ___ states that the weight on each layer of a star is balanced by the pressure in that layer.
the law of hydrostatic equilibrium
The Milky Way Galaxy is a part of a galaxy cluster known as ___.
the local group
In the context of main-sequence stars, which of the following statements is true of a mass-luminosity relation?
the more massive a star, the more luminous it is.
which of the following was discovered by Galileo Galilei
the mountains and valleys on the surface of the moon
The mass of the Milky Way Galaxy can be estimated by:
the orbital motions of the stars within the galaxy.
Kepler's first law of planetary motion implies that:
the planets move in elliptical orbits around the Sun.
Kepler's first law of planetary motion implies that: uniform circular motion is adequate to describe the motion of all the planets. the planets move at constant speeds at all points in their orbits. all the planets move around Earth in elliptical orbits. the planets move in elliptical orbits around the Sun.
the planets move in elliptical orbits around the Sun. Correct. Kepler's first law of planetary motion states that the orbits of the planets around the Sun are ellipses with the Sun at one focus.
An observer's nadir is
the point directly opposite the observer's zenith
An observer's nadir is:
the point directly opposite the observer's zenith
The Babcock model explains:
the reversal of the Sun's magnetic field from cycle to cycle.
Which of the following is the most precise method for measuring the mass of a galaxy?
the rotation curve method
cosmology
the study of the universe; its origins how do we believe the universe works
orbital velocity
the velocity with which an object moves in orbit
___ is the location on the H-R diagram where stars first reach stability as hydrogen-fusing stars.
the zero-age main sequence
Which of the following is true of asteroids?
they are small rock worlds
The Jovian planets have low density because:
they formed in the outer solar nebula where water vapor could freeze to form ice particles.
Which of the following is true of spring tides ?
they occur at new moon and full moon
A lunar eclipse that occurs when the Moon moves completely into Earth's umbral shadow is called a _____.
total lunar eclipse
The Sun reaches its most southern point at the _____
winter solstice
48. One light-year (ly) is about _____.
d. 63,000 AU
Asterism
A named grouping of stars that is not one of the recognized constellations.
Sometimes when a theory has been refined, tested, and confirmed so often that scientist have great confidence in it, it is called
A natural law
Sometimes, when a theory has been refined, tested, and confirmed so often that scientists have great confidence in it, it is called__________.
A natural law
We can't see a new moon in our sky because
A new moon is quite near the Sun in the sky
The _____ is a measure of the rate of expansion of the Universe
Hubble Constant
About 75 percent of the mass of interstellar gas is ___.
Hydrogen
About 75 percent of the mass of interstellar gas is _____.
Hydrogen
Analysis of the solar spectrum shows that the sun is mostly _____
Hydrogen
What is the name of the element that begins fusing in stars?
Hydrogen
Which of the following element is NOT created in stars
Hydrogen
Which of the following is the most abundant element in the universe
Hydrogen
The two most abundant elements in the Sun are:
Hydrogen and helium
synodic period
The period of rotation or revolution of a celestial body with respect to the sun
sidereal period
The periodic rotation or revolution of an astronomical body relative to the stars
In the context of the Sun's surface, which of the following is the source of most of the sunlight received by Earth?
The photosphere
In the context of the Sun's surface, which of the following is the source of most of the sunlight received by Earth? The photosphere The convection zone The chromosphere The corona
The photosphere
In the context of the sun surface which of the following is a source of most of the sunlight received by earth
The photosphere
Keller's first law of planetary motion implies that
The planets move in elliptical orbits around the sun
penumbra
The potion of a shadow that is only partially shaded
path of totality
The track of the moon's umbral shadow over Earth's surface. The sun is totally eclipsed as seen from within this path
27. Which of the following is an example of a galaxy?
b. The Milky Way Galaxy
The Copernican model explained Earth's daily and seasonal changes as well as the changing ____________ of the planets.
brightness
L dwarfs and T dwarfs are spectral classes of ___.
brown dwarf stars
L dwarfs and T dwarfs are spectral classes of _____.
brown dwarf stars
42. The average distance from Earth to the Sun is about _____.
d. 93 million miles
The flow of energy through each shell determines:
how much weight a shell can balance.
The faintest stars are the __________ stars.
sixth-magnitude
relationship between hypothesis, theory, and natural law
-hypothesis = a conjecture, subject to further tests, that account for a set of facts -theory = system of assumptions and principles applicable to a wide range of phenomena that has been repeatedly verified -natural law = a theory that has been so well confirmed that it is almost universally accepted as correct -no clear distinction, sometimes tradition; darwin's law is called theory
net force
-if forces are equal = cancel out = no motion -how combination of all forces on object affect motion =will go in direction of stronger force =is not zero when direction or speed/ acceleration changes
Galileo Galilei contributions
-many discoveries that supported Copernican model -moons surface is not perfect -four "planets" around jupiter, today the Galilean moons of Jupiter = jupiter moved with satellite so could earth, centers of motion besides earth -later discoveries = venus phases like moon, not possible in ptolemaic model
Newton's discoveries affect on discipline of science
-newton's discoveries made astronomy an analytical science; could measure positions and motions of bodies, calculate gravitational forces, and predict future motion -cause and affect = Newton's second law was first clear statement of it, confidence that every effect has cause
How objects orbit each other
-objects orbiting each other are actually revolving around their mutual center of mass, the balance point of the system, closer to the more massive object -ex: earth and moons center of mass is close to earth's center, inside earth
Nicolaus Copernicus model
-sun at center of universe, earth rotated on axis and revolved around sun first person to produce a detailed heliocentric model of the Universe with substantial justifying arguments = motion of planets is straightforward without epicycles = earth overtakes and passes planets, retrograde (westward motion) -still couldn't predict positions of planets any more accurately that old model = still believed wrongly in uniform motion, even had to reintroduce small epicycles -copernican model with circular motion is incorrect, copernican hypothesis of heliocentric solar system is correct
Isaac Newtons contributions
-three laws that relate the motion of a body to forces acting on it = can predict how it will move -force that holds moon close to earth is same that makes apples fall -his laws of gravitation make it possible to understand why and how body's orbit others, and why kepler's laws work -Isaac Newton guessed that gravity works by an inverse square relation because he had already discovered that light behaves this way
what produces tides
-tides caused by small differences in gravitational force -pull on each other on sides closer = bulges on far sides, oceans are deeper there -earth rotates and carries you into bulge = see tides creeping higher -two bulges = two high tides a day -sun also produces tides on earth
Gallileo's trial - main conflict
-trial not for belief in copernican model, but for disobeying orders in 1616 to stop defending them -trial was result of conflict between two ways of understanding universe = religious faith, and observation
When looking at our sky, the sun and moon look about ** inches in diameter
.5 or 1/2
The average distance from Earth to the Sun is
1 AU
What is Earth's distance from the sun?
1 AU
The moon moves approximately ________ degrees in a 24-hour time period.
13
Milankovitch developed his hypothesis in _______.
1920
geosynchronous satellite
1a A ______________ ____________ orbits eastward with the rotation of Earth and remains above a fixed spot on the equator, which is ideal for communications and weather satellites.
not, parallax, object, different, distorting, constellations, small
1a Ancient astronomers believed that Earth did ____ move because they saw no __________, the apparent motion of an __________ because of the motion of the observer. To demonstrate parallax, close one eye and cover a distant object with your thumb held at arm's length. Switch eyes, and your thumb appears to shift position as shown at left. If Earth moves, ancient astronomers reasoned, you should see the sky from _________ locations at different times of the year, and you should see parallax ______________ the shapes of the ________________. They saw no parallax, so they concluded Earth could not move. Actually, the parallax of the stars is too ______ to see with the unaided eye.
straight line, continuously accelerate, curved orbit
1b According to Newton's first law of motion, the Moon should follow a ___________ _______ and leave Earth forever. Because it follows a curve, Newton knew that some force must ______________ ______________ it toward Earth, gravity. Every second the Moon moves 1020 m (3350 ft) eastward and falls about 1.4 mm (1/18 in.) toward Earth. The combination of these motions produces the Moon's ___________ _______. The Moon is falling all the time.
gravity, miss, free fall, each other, mutual, center of mass, closer, massive
1c Astronauts in orbit around Earth feel weightless, but they are not—to use a term from old science fiction movies—"beyond Earth's gravity." Like the Moon, the astronauts are accelerated toward Earth by Earth's __________, but they travel fast enough along their orbits that they continually "_______ the Earth." They are literally falling around Earth. Inside or outside a spacecraft, astronauts feel weightless because they and their spacecraft are falling at the same rate. Rather than saying they are weightless, you should more accurately say they are in ________ _______. 2 To be accurate you should not say that an object orbits Earth. Rather, the two objects orbit ______ _______. Gravitation is ___________, and if Earth pulls on the Moon, the Moon pulls on Earth. The two bodies revolve around their common __________ ____ ______, the balance point of the system. 2a Two bodies of different mass balance at their center of mass, which is located ____________ to the more ______________ object. As the two objects orbit each other, they revolve around their common center of mass as shown at right. The center of mass of the Earth-Moon system lies only 4670 km (2900 mi) from the center of Earth—inside Earth. As the Moon orbits the center of mass on one side, Earth swings around the center of mass on the opposite side.
Planetary motion, wanderer, stop, westward, retrograde motion, gears
2 _______________ __________ was a big problem for ancient astronomers. In fact, the word planet comes from the Greek word for "_____________," referring to the eastward motion of the planets against the background of the fixed stars. The planets did not, however, move at a constant rate, and they could occasionally ________ and move _______________ for a few months before resuming their eastward motion. This backward motion is called _________________ ______________. (retrograde motion of planets is an optical illusion created when earth passes slower moving planets further out in orbit) 2a Simple uniform circular motion centered on Earth could not explain retrograde motion, so ancient astronomers combined uniformly rotating circles much like __________ in a machine to try to reproduce the motion of the planets.
What is the highest mass a neutron star can reach before it collapses into a black hole?
2 to 3 solar masses
The halo in the spherical component of the Milky Way contains about ___ as many stars as the disk of the galaxy.
2%
repeating, escape velocity, open orbit, lowest, farthest, highest, closest, perigee
3 Closed orbits are __________ cycles. The Moon and artificial satellites orbit Earth in closed orbits. Below, the cannonball could follow an elliptical or a circular Closed orbits. If the cannonball travels at the velocity needed to leave Earth permanently, called ___________ ____________, it will enter an _______ ______. An open orbit does not return the cannonball to Earth; it will escape. 3a As described by Kepler's second law, an object in an elliptical orbit has its _____________ velocity when it is _____________ from Earth (apogee), and its _____________ velocity when it is _________ to Earth (perigee). _____________ must be above Earth's atmosphere, or friction will rob the satellite of energy and it will quickly fall back to Earth.
Claudius Ptolemy, epicycle, deferent, approximate, off center, epicycle, equant, epicycles
3 Uniformly rotating circles were key elements of ancient astronomy. ___________ ___________ created a mathematical model of the Aristotelian universe in which the planet followed a small circle called the __________ that slid around a larger circle called the _____________. By adjusting the size and rate of rotation of the circles, he could _______________ the retrograde motion of a planet. See illustration at right. To adjust the speed of the planet, Ptolemy supposed that Earth was slightly ___ ____________ and that the center of the _______ moved such that it appeared to move at a constant rate as seen from the point called the _____________. To further adjust his model, Ptolemy added small _______________ (not shown here) riding on top of larger epicycles, producing a highly complex model. (https://www.youtube.com/watch?v=utH-GHH1FT8)
first principles, examination, reexamined, circular, constant, motionless, center, backward, planets
3-1a Aristotle's Universe Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from _______ ____________. A first principle was something that seemed obviously true to everyone and supposedly needed no further _____________. That may strike you as peculiar; modern thinkers tend to observe how things work and then from that evidence make principles and conclusions that can always be ______________. Before the Renaissance, however, reasoning from evidence (which you might call "scientific thinking") was not widespread. Study Concept Art 3A, "The Ancient Universe," and notice three important ideas: 1) Ancient philosophers and astronomers accepted without question—as first principles— that heavenly objects must move on __________ paths at ___________ speeds, and that the Earth was _____________ at the __________ of the Universe. Although a few ancient writers mentioned the possibility that Earth might move, most of them did so in order to point out how that idea was "obviously" wrong. 2) As viewed by you from Earth, the planets seem to follow complicated paths in the sky, including episodes of "__________" motion that are difficult to explain in terms of motion on circular paths at constant speeds. 3) Finally, you can see how Ptolemy created an elaborate geometrical and mathematical model to explain details of the observed motions of the ____________ while assuming Earth was motionless at the center of the Universe.
Nicolaus Copernicus, heavens, earth, christian, heresy
3-2 NICOLAUS COPERNICUS ______________ ______________ (originally, Mikolaj Kopernik) was born in 1473 in what is now Poland (Figure 3-1). At the time of his birth—and throughout his life—astronomy was based on Ptolemy's model of Aristotle's universe. In spite of many revisions, the Ptolemaic model was still a poor predictor of planet positions, but because of the authority of Aristotle, widely accepted. Moreover, because in Aristotle's philosophy the most perfect region was in the ____________ and the most imperfect region was at ___________'s center, the classical geocentric universe model matched the commonly held ___________ view of the geometry of heaven and hell. Anyone who criticized Aristotle's model of the Universe was thereby also challenging belief in the locations of heaven and hell, risking at least criticism and perhaps a serious charge of _________ with a possible death penalty. (Nicolaus Copernicus (Latinized version of his birth name, Mikolaj Kopernik) pursued a lifetime career in the Church, but he was also a talented mathematician and astronomer. His work triggered a revolution in human thought)
church, hesitated, Sun, heliocentric, detailed model, 1514
3-2a Copernicus's Model Copernicus was associated with the Roman Catholic ____________ throughout his life. His uncle, by whom he was raised and educated, was a bishop. After studying medicine and Church law in some of the major universities in Europe, Copernicus became a Church employee, serving as secretary and personal physician to his powerful uncle for 15 years and moving into quarters in the cathedral after his uncle died. Because of this connection to the Church and his fear of persecution, he _____________ to publish his revolutionary ideas that challenged the Ptolemaic model and, indirectly, belief in heaven and hell. What were these revolutionary ideas? Copernicus believed that the _______ and not Earth was the center of the Universe and that Earth rotated on its axis and revolved around the Sun. Copernicus apparently began doubting Ptolemy's geocentric model during his college days. A _____________ universe model (Sun centered, from the Greek word for Sun, helios) had been discussed occasionally before Copernicus's time, but Copernicus was the first person to produce a ____________ ______________ with substantial justifying arguments. Sometime before _______, Copernicus wrote a short pamphlet summarizing his model and distributed it in handwritten form while he worked on his book.
De Revolutionibus Orbium Coelestium, 1530, 1542, center, faster, overtakes, steadily, westward, loop, angle, orbital planes, separate
3-2b De Revolutionibus Copernicus's book ___ ___________________ ____________ _____________ (On the Revolutions of Celestial Spheres) was essentially finished by about ________. He hesitated to publish, although other astronomers, and even church officials concerned about reform of the calendar, knew about his work, sought his advice, and looked forward to the book's publication. In _________ Copernicus finally sent the manuscript for De Revolutionibus off to be printed. He died in 1543 before the printing was completed. The most important idea in the book was that the Sun was the _________ of the Universe. That single innovation had an impressive consequence—the retrograde motion of the planets was immediately explained in a straightforward way without the epicycles that Ptolemy used. In Copernicus's model, which you can see in Figure 3-3, Earth moves _______ along its orbit than the planets that lie farther from the Sun. Consequently, Earth periodically ____________ and passes these planets. Imagine that you are a runner on a track moving along an inside lane. Runners well ahead of you appear to be moving forward relative to background scenery. As you overtake and pass slower runners in outside lanes, they fall behind, seeming to move backward for a few moments relative to the scenery. The same thing happens as Earth passes a planet such as Mars. Although Mars moves __________ along its orbit, as seen from Earth it seems to slow to a stop and move ____________ (retrograde) relative to the background stars as Earth passes it (Figure 3-2). Because the planets' orbits do not lie in precisely the same plane, a planet does not resume its eastward motion in precisely the same path it followed earlier. Instead, it describes a ________ with a shape depending on the ______________ between the two __________ __________. (figure 3-2- Earth and Mars are shown at equal intervals to show that as Earth overtakes Mars (a-c), Mars appears to slow its eastward motion. As Earth passes Mars (d), Mars appears to move westward. As Earth draws ahead of Mars (e-g), Mars resumes its eastward motion against the background stars.) ((a) The Copernican universe, as reproduced in his book De Revolutionibus. Earth and all the known planets revolve in ____________ circular orbits about the Sun (Sol) at the center. The outermost sphere carries the immobile stars of the celestial sphere. Notice the orbit of the Moon around Earth (Terra). (b) The model is simple not only in the arrangement of the planets but also in their motions. Orbital velocities (blue arrows) decrease from that of Mercury, the fastest, to that of Saturn, the slowest.)
Tycho Brahe, geocentric, Sun
3-3a Tycho Brahe The Danish nobleman _________ _________ is remembered in part for wearing false noses to hide a dueling scar from his college days (Figure 3-4). He was reportedly very proud of his noble station, so his disfigurement probably did little to improve his lordly disposition. (Tycho Brahe was, during his lifetime, the most famous astronomer in the world. Tycho's model of the Universe retained the first principles of classical astronomy; it was ______________ with the Sun and the Moon revolving around Earth, but the planets revolved around the _______. All motion was along circular paths)
Johannes Kepler, copernican hypothesis, The Forerunner of Dissertations on the Universe,
3-3b Johannes Kepler No scientist could have been more different from Tycho Brahe than was _____________ ___________. He was born in 1571, the oldest of six children in a poor family living in what is now southwest Germany. His father, who fought as a mercenary soldier for whomever could afford his fees, eventually disappeared. Kepler's mother was apparently an unpleasant and unpopular woman. She was accused of witchcraft in her later years, and Kepler defended her (successfully) in a trial that dragged on for 3 years. Kepler himself had poor health, even as a child, so it is surprising that he did well in school, winning promotion to a Latin school and eventually a scholarship to the university at Tübingen, where he studied to become a Lutheran pastor. While still a college student, Kepler had become a believer in the _____________ ___________. During his last year of study, Kepler accepted a teaching job in the town of Graz, in what is now Austria, which allowed him to continue his studies in mathematics and astronomy. By 1596, the same year Tycho arrived in Prague, Kepler had learned enough to publish a book called ____ ________________ ____ _______________ ___ _____ ___________, Containing the Mystery of the Universe. The book is more commonly known by an abbreviation of its original Latin title: Mysterium Cosmographicum (Figure 3-5). (a) Johannes Kepler was Tycho Brahe's successor. (b) This diagram, based on one drawn by Kepler, shows how he believed the sizes of the celestial spheres carrying the outer three planets—Saturn, Jupiter, and Mars—are determined by spacers (blue) consisting of two of the five regular solids. Inside the sphere of Mars, the remaining regular solids separated the spheres of Earth, Venus, and Mercury (not shown in this drawing). The Sun lay at the very center of this Copernican universe based on geometrical spacers. (c) The five regular solids are the tetrahedron, cube, octahedron, dodecahedron, and icosahedron, the only shapes with all faces of equal sizes and all equal angles between the faces.)
ellipse, foci, constant
3-3c Kepler's Three Laws of Planetary Motion Although Kepler dabbled in the philosophical arguments of the day, he was a mathematician, and his triumph was the solution of the problem of the motion of the planets. The key to his solution was the _________. An ellipse is a figure drawn around two points, called the ______, in such a way that the distance from one focus to any point on the ellipse and back to the other focus equals a ________. This makes it easy to draw ellipses with two thumbtacks and a loop of string. Press the thumbtacks into a board, hook the string about the tacks, and place a pencil in the loop. As you can see in Figure 3-6a, if you keep the string taut as you move the pencil, it traces out an ellipse. (The geometry of elliptical orbits. (a) Drawing an ellipse with two tacks and a loop of string. (b) The semi-major axis, a, is half of the longest diameter. (c) Kepler's second law is demonstrated by a planet that moves from A to B in one month and from A' to B' in the same amount of time. The two blue sectors have the same area.)
telescope, build, observe, apply, moon, shadows, four, galilean moons
3-4a Telescopic Observations It was the __________ that drove Galileo to publicly defend the heliocentric model. Galileo did not invent the telescope. It was apparently invented around 1608 by lens makers in Holland. Galileo, hearing descriptions in the fall of 1609, was able to _____ working telescopes in his laboratory. Galileo was also not the first person to look at the sky through a telescope, but he was the first person to ______ the sky carefully and ______ his observations to the main theoretical problem of the day—the place of Earth. What Galileo saw through his telescopes was so amazing he rushed a small book into print, Sidereus Nuncius (The Starry Messenger). In that book he reported two major discoveries about the Solar System. First, the ______ was not perfect. It had mountains and valleys on its surface, and Galileo used the _______ to calculate the height of the mountains. Aristotle's philosophy held that the Moon was perfect, but Galileo showed that it was not only imperfect but was even a world like Earth. Second, Galileo's telescope revealed ____ new "planets" circling Jupiter, planets that we know today as the ________ _____ of Jupiter, shown in Figure 3-8.
cease, 1632, aristotle, ptolemy, debate, ridicule
3-4b Dialogo and Trial In 1623 Galileo's friend Cardinal Barberini became pope, taking the name Urban VIII. Galileo went to Rome in an attempt to have the 1616 order to _____ debate lifted. Although that attempt was unsuccessful, Galileo began to write a massive defense of Copernicus's model, completing it in 1629. After some delay, Galileo's book was approved by both the local censor in Florence and the head censor of the Vatican in Rome. It was printed in ______. Called Dialogo Sopra i Due Massimi Sistemi del Mondo (Dialogue Concerning the Two Chief World Systems), it confronts the ancient astronomy of _______ and _______ with the Copernican model. Galileo wrote the book as a _______ among three friends. Salviati is a swift-tongued defender of Copernicus; Sagredo is intelligent but largely uninformed; Simplicio is a dim-witted defender of Ptolemy. The book was a clear defense of Copernicus, and, either intentionally or unintentionally, Galileo exposed the pope's authority to _______. Urban VIII was fond of arguing that, as God was omnipotent, God could construct the Universe in any form while making it appear to humans to have a different form, and thus its true nature could not be deduced by mere observation. Galileo placed the pope's argument in the mouth of Simplicio. The pope took offense and ordered Galileo to face the Inquisition.
religious, observations, contradicted, modern science
3-4c Two Ways to Understand the World Galileo was tried and condemned on a charge you might call a technicality. Why then is his trial so important that historians have studied it for almost four centuries? Why have some of the world's greatest authors, including Bertolt Brecht, written about Galileo's trial? Why in 1992 did a commission established by Pope John Paul II report that the Inquisition had erred in condemning Galileo? To understand the trial, you must recognize that it was the result of a conflict between two ways of understanding the Universe. Since the Middle Ages, European scholars had taught that the only path to true understanding was through ________ faith. St. Augustine (354-430) wrote "Credo ut intelligam," which can be translated as, "Believe in order to understand." Galileo and other scientists of the Renaissance, however, used their own ___________ as evidence to try to understand the Universe; when their observations __________ religious authorities, they assumed their observations of reality were correct. (See How Do We Know?.) Galileo paraphrased Cardinal Baronius in saying, "The Bible tells us how to go to heaven, not how the heavens go." The significance of Galileo's trial is about the birth of _______ _______ as a new way to understand the Universe.
optics, laws of motion, nature of gravity, invented calculus, move
3-5a Isaac Newton Galileo died in January 1642. Some 11 months later, on Christmas day 1642, Isaac Newton was born in the English village of Woolsthorpe. Newton's life represented the flowering of the seeds planted by the previous four astronomers in this story, Copernicus, Tycho, Kepler, and Galileo. Newton was a quiet child from a farming family, but his work at school was so impressive that his uncle financed his education at Trinity College, where he studied mathematics and physics. In 1665, plague swept through England, and the colleges were closed. During 1665 and 1666, Newton spent his time back home in Woolsthorpe, thinking and studying. It was during these years that he made most of his scientific discoveries. Among other things, he studied _____, developed three _____ __ _____, probed the _____ __ _____, and _______ _______. The publication of his work in his book Philosophia Naturalis Principia Mathematica, know as the Principa (pronounced prin-KIP-ee-ah), in 1687 placed the fields of physics and astronomy on a new firm base. It is beyond the scope of this book to analyze all of Newton's work, but his laws of motion and gravity had an important impact on the future of astronomy. From his study of the work of Galileo, Kepler, and others, Newton extracted three laws that relate the motion of a body to the forces acting on it (Table 3-2). These laws made it possible to predict exactly how a body would _____ if the forces were known.
moon, planets, Kepler's, falling, misses, velocity, mass, open orbit
3-5b Orbital Motion Newton's laws of motion and gravitation make it possible for you to understand why and how the ______ orbits Earth, the __________ orbit the Sun, and to discover why ____________ laws work. To understand how an object can orbit another object, read Concept Art 3B, "Orbiting Earth." You need to see orbital motion as Newton did. Begin by noticing three important ideas: 1) An object orbiting Earth is actually ____________ (being accelerated) toward Earth's center. An object in a stable orbit continuously ____________ Earth because of its horizontal ____________. 2) Objects orbiting each other actually revolve around their mutual center of ________. 3) Notice the difference between closed orbits and open orbits. If you want to leave Earth never to return, you must give your spaceship a high enough velocity so it will follow an ________ ________
general laws, predictive, analytical, measure, position, motion, cause and effect, second law, acted on, rational, causes
3-5d Newton's Universe Newton's insight gave the world a new conception of nature. His laws of motion and gravity were __________ __________ that described the motions of all bodies under the action of external forces. In addition, the laws were ________ because they made possible specific calculations of predictions that could be tested by observation. For example, Newton's laws of motion can be used to derive Kepler's third law from the law of gravity. Newton's discoveries remade astronomy into an ___________ science in which astronomers could ___________ the ___________ and ___________ of celestial bodies, calculate the gravitational forces acting on them, and predict their future motion. One of the most often used and least often stated principles of science is __________ ____ __________. You could argue that Newton's __________ ________ of motion was the first clear statement of that principle. Ancient philosophers such as Aristotle believed that objects moved because of innate tendencies; for example, objects made of earth or water had a natural tendency to move toward Earth at the center of the Universe. In contrast, Newton's second law says if an object changes its motion by an acceleration, then it must have been ________ ___ by a force. The principle of cause and effect gives scientists confidence that every effect has a cause. If the Universe were not rational, then you could never expect to discover causes. Newton's second law of motion was arguably the first explicit statement that the behavior of the Universe is _________ and depends on _________. (See "What Are We?")
Except Mercury's orbit, the rest of the planets' orbital planes are inclined by no more than ___.
3.4 degrees
In 1928 the International Astronomical Union clearly defined the boarders of _____ constellations.
88
There are ** modern day constellations
88
Constellations
88 defined in the universe.
paradigm
= a commonly accepted set of scientific ideas and assumptions -paradigms limit questions we ask, limit what we understand
How the sun produces tides = spring and neap tides
= at new and full they add with lunar to create extra high and extra low tides = spring tides =at first and third quarter solar tides cancel out part of lunar tides, less extreme = neap tides
ellipse
= closed curve around two points (foci) total distance from one focus to the curve and back to the other focus remains constant (at any point) -string and pencil example
inverse square relationship of gravity
= force of gravity decreases as square of distance between them increases -ex: if distance between moon and earth doubled, force would decrease by factor of 2^2 or 4 -force of gravity attracting two objects equals a constant times the product of their masses divided by the square of the distance between them
geosynchronous satellite
= orbits eastward with rotation of earth and remains above fixed spot on the equator
Claudius Ptolemy's contributions
= same basic ideas as Aristotle -practical not philosophical, used math to describe the motion of planets -weakened first principles = showed earth a little off center, slightly varied planet speeds = epicycles slid around larger circle called deferent to explain retrograde motion =added equant, earth slightly off center -still not good at making predictions = accepted due to Aristotle's popularity
first principle
= something that seems obviously true and needs no further examination
Aristotle's model of the universe
= uniform circular motions, geocentric -first principles that heavenly objects must move on circular paths at constant speeds, earth was motionless at center -saw no parallax = believed earth did not move
circular velocity
= velocity needed to stay in circular orbit, depends on mass of planet and distance from center of planet, once reached object will fall around object it is orbiting forever
two numbers that describe geometry of ellipse
=semi major axis = half the length of longest diameter of the ellipse =eccentricity = half distance between foci divided by semi major axis; tells shape = closer to 0 is more circular, more elongated if near 1
Asterisms
A group of stars thay are less formally defined. Example: Big Dipper.
Kepler wrote 3 laws of planetary motion. What does his second law tell us?
A line from the planet to the Sun sweeps over equal areas in equal intervals of time
total lunar eclipse
A lunar eclipse in which the moon completely enters Earth's dark shadow
partial lunar eclipse
A lunar eclipse in which the moon does not completely enter Earth's shadow
Apparent visual magnitude (mv)
A measure of the brightness of a star as seen by human eyes from Earth.
Flux
A measure of the flow of energy through a surface. Usually applied to light.
Intensity
A measure of the light energy from a star that hits 1 square meter in 1 second. (I.E if two stars have intensities 1a & 1b they are compared as 1a/1b.
diamond ring effect
A momentary phenomenon seen during some total solar eclipses when the ring of the corona and a bright spot of photosphere resemble a large diamond set in a silvery ring
The visible star nearest the Sun,__________, has a parallax of only 0.76 arc seconds.
Alpha Centauri
In the context of luminosity classes,__________is a subgiant (IV).
Altair
Copernican Revolution
Although astronomers throughout Europe read and admired De Revolutionibus and found Copernicus's astronomical observations and mathematics to have great value, few astronomers believed, at first, that the Sun actually was the center of the Solar System and that Earth moved. How the Copernican hypothesis was gradually recognized as correct has been called the _____________ ________________, because it was not just the adoption of a new idea but a total change in the way astronomers and the rest of humanity thought about the place of Earth.
Uranometria
An atlas of the sky that assigned lowercase Greek letters to the brighter stars each constellation in approx. order of brightness. ( publish. in 1603 by Bavarian lawyer Johann Bayer).
Which of the following is true of ancient constellation?
Ancient constellation boundaries, when they were defined at all, were only approximate.
Jack, a quarterback, imparts a spin with his fingers when he throws the football during a match. The concept of _____ explains why the ball continues to spin rapidly as it flies through the air
Angular Momentum
A(n)__________occurs when the Moon is at its greatest distance from Earth and the Moon is new. annular solar eclipse partial lunar eclipse total solar eclipse total lunar eclipse
Annular Solar Eclipse
A(n)__________occurs when the Moon is at its greatest distance from Earth and the Moon is new
Annular solar eclipse
Evening star
Any PLANET visible in the evening sky
Morning star
Any PLANET visible in the sky before sunrise
Star brightnesses expressed in the magnitude system are known as ___, describing how the stars look to human eyes observing from Earth.
Apparent Visual Magnitudes
Red dwarfs
Are cool and small with low luminosities
heavens, spheres, vary, sizes, locations
Aristotle lived in Greece from the year 384 to 322 BCE. He believed as a first principle that the _________ were perfect. Because the sphere and circle were considered the only perfect geometrical figures, Aristotle also believed that all motion in the perfect heavens must be caused by the rotation of spheres carrying objects around in uniform circular motions. Aristotle's writings became so famous that he was known throughout the Middle Ages as "The Philosopher," and the geocentric universe of nested ___________ that he devised dominated astronomy. His opinions on the nature of Earth and the sky were widely accepted for almost 2000 years. Claudius Ptolemy, a mathematician who lived roughly 500 years after Aristotle, believed in the basic ideas of Aristotle's universe but was interested in practical rather than philosophical questions. For Ptolemy, first principles took second place to accuracy. He set about making an accurate mathematical description of the motions of the planets. Ptolemy weakened the first principles of Aristotle by moving Earth a little off-center in the model and inventing a way to slightly _______ the planets' speeds. This made his model (published around the year 140) a better match to the observed motions. Aristotle's universe, as embodied in the mathematics of Ptolemy's model, dominated ancient astronomy. At first the Ptolemaic model predicted positions of the planets with fair accuracy; but as centuries passed, errors accumulated, and Islamic and later European astronomers had to update the model, adjusting the _________ and ______________ of the circles and changing the rates of motion.
What is the relationship between the angle an object sub tends on the sky and the distance to the object
As object gets closer its angular size increases
Ron is standing near a railroad track. A train is moving toward him at 60 mph, and it blows its horn. What will Ron notice as the train moves past him? As the train approaches, the horn will sound higher in pitch than when the train moves away. The horn will produce a multiple echo effect as the train moves closer to Ron. There will be no change in the pitch of the horn as the train moves past Ron. As the train moves away, the frequency of the horn will be higher than when the train comes closer.
As the train approaches, the horn will sound higher in pitch than when the train moves away.
The average distance between the Earth and the Sun.
Astronomical Unit
The average distance from Earth to the Sun is called the
Astronomical Unit
Jupiter's extensive magnetosphere is responsible for ___ around the magnetic poles.
Aurorae
Jupiter's extensive magnetosphere is responsible for ____ around the planet's magnetic poles
Aurorae
The eerie and pretty northern and southern lights that are produced when gases in Earth's upper atmosphere glow from energy delivered by the solar wind are referred to as ___.
Aurorae
The Sun crosses the celestial equator going southward at the point called the ___.
Autumnal Equinox
The Sun crosses the celestial equator going southward during the Northern Hemisphere ___.
Autumnal Equinox
The Sun is on the celestial equator during the
Autumnal equinox and the vernal equinox
Milankovitch hypothesis
Changes in orbit trigger ice ages 3 factors: orbit, precession, inclination.
spacing, orbits, motions, mars, ellipse, faster, sun, radius
By modern standards, the book contains almost nothing of value. It begins with a long appreciation of Copernicus's model and then goes on to mystical speculation on the reason for the ________ of the planets' orbits. The second half has one virtue—as Kepler tried to understand planet _______, he demonstrated that he was a talented mathematician and that he had become well versed in astronomy. He sent copies to Tycho and to Galileo, who both recognized Kepler's talent in spite of the mystical parts of the book. Life was unsettled for Kepler in Graz because of the persecution of Protestants in that region, so when Tycho Brahe invited him to Prague in 1600, Kepler went eagerly, ready to work with the famous astronomer. Tycho's sudden death in 1601 left Kepler in a position to use Tycho's extensive records of observations to analyze the ___________ of the planets. Kepler began by studying the motion of ____, trying to deduce from the observations how the planet actually moved. By 1606, he had solved the mystery: The orbit of Mars is an __________, not a circle. Thus, he abandoned the ancient belief in the circular motion of the planets. But the mystery was even more complex. The planets do not move at uniform speeds along their elliptical orbits. Kepler recognized that they move _______ when closer to the _______ and slower when farther away. Thus Kepler abandoned both uniform motion and circular motion and thereby finally solved the problem of planetary motion. Later, he discovered that the period of each planet's orbit is related to that orbit's __________. Kepler published his results in 1609 and 1619 in books called, respectively, Astronomia Nova (New Astronomy) and Harmonices Mundi (The Harmony of the World).
Milankocitch
Changes in the shape of the earths orbit can trigger ice ages
plato, perfect, sphere, uniform circular motion, Aristotle, imperfect, geocentric universe, 55
CONCEPT ART 3A AN ANCIENT MODEL OF THE UNIVERSE 1 For 2000 years, the minds of astronomers were shackled by a pair of ideas. The Greek philosopher _________ argued that the heavens were ____________. Because the only perfect geometrical shape is a ____________, which carries a point around in a circle as it rotates, and because the only perfect motion is uniform motion, Plato concluded that all motion in the heavens must be made up of combinations of circles turning at uniform rates. This idea was called __________ ____________ ___________. Plato's student _____________ argued that Earth was ______________ and lay at the center of the Universe. Such a model is known as a _______________ _____________. His model contained _____ spheres turning at different rates and at different angles to carry the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn across the sky. Aristotle was known as the greatest philosopher in the ancient world, and for 2000 years his authority chained the minds of astronomers with uniform circular motion and geocentrism. See the model at right.
higher, orbit, circular velocity, 88
CONCEPT ART 3B ORBITS 1 You can understand orbital motion by thinking of a cannonball moving around Earth in a circular path. Imagine a cannon on a high mountain aimed horizontally as shown at right. A little gunpowder gives the cannonball a low velocity, and it doesn't travel very far before falling to Earth. More gunpowder gives the cannonball a ________ velocity, and it travels farther. With enough gunpowder, the cannonball travels so fast it never strikes the ground. Earth's gravity pulls it toward Earth's center, but Earth's surface curves away from it at the same rate it falls. It is in _______. The velocity needed to stay in a circular orbit is called _________ _______. Just above Earth's atmosphere, at an altitude of 200 km, circular velocity is 7790 m/s or about 17,400 miles per hour, and the orbital period is about _____ minutes (A satellite above Earth's atmosphere feels no friction and will fall around Earth indefinitely.Earth satellites eventually fall back to Earth if they orbit too low and experience friction with the upper atmosphere)
According to the _____, the Moon formed elsewhere in the solar nebula and was later taken by Earth.
Capture hypothesis
In the context of giant stars, helium fusion produces ___ that accumulate in an inert core.
Carbon and oxygen
tidal bulges
Caused by the gravitational forces of the Moon, and to a lesser extent the Sun
An imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun, and Moon seem to be attached.
Celestial Sphere
The ___ is an imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun, and Moon seem to be attached.
Celestial Sphere
The ______ is an imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun, and moon seem to be attached
Celestial sphere
Which of the following is the largest object in the asteroid belt?
Ceres
Aristotle, Claudius Ptolemy, substances, center
Ch 3-1 ASTRONOMY BEFORE COPERNICUS To understand why Copernicus's work was so important, you first need to backtrack to ancient Greece and meet the two great authorities of ancient astronomy, the brilliant philosopher ______________ and a later follower of Aristotle's principles, _____________ _____________, whom you first met in Chapter 2 Section 2-1c in the context of measuring the brightness of stars. Recall from Chapter 1 the differences among Solar System, galaxy, and Universe. The early astronomers discussed here didn't know there were other galaxies. They didn't know that we live inside a galaxy. They didn't even know that the stars were other objects like the Sun. They thought the entire Universe consisted of Earth, the Sun, the Moon, and five moving points of light they called planets. Furthermore, they did not know that the planets are composed of _____________ much like Earth's. They imagined that all of this was enclosed inside the celestial sphere that lay just beyond the most distant planet, Saturn. Their entire Universe was quite small, and they imagined that Earth lay at the ________.
A white dwarf can only reach a maximum mass of about 1.4 solar masses because if it had any more mass, it would collapse on itself. What is this limit called?
Chandrasekhar Limit
16th, Copernicus, Galileo Galilei, Isaac Newton
Chapter 3- The preceding chapters gave you a modern view of Earth. You can now imagine how Earth, the Moon, and the Sun move through space and how that produces the sights you see in the sky. But how did humanity first realize that we live on a planet moving through space? This realization required the revolutionary overthrow of an ancient and honored idea of Earth's place. By the ______ century, many astronomers were becoming uncomfortable with the idea that Earth sat at the center of a spherical Universe. In this chapter, you will discover how an astronomer named _________________ directly challenged that idea, how ______________ ______________ changed the rules of the debate, and how ________ ____________ changed humanity's concept of nature. (See CO 3.) Here you will find answers to four important questions: 1) How did classical philosophers describe Earth's place in the Universe? 2) How did Copernicus revise that ancient concept? 3) Why was Galileo condemned by the Inquisition? 4) How did Isaac Newton change the way people thought about nature and themselves? This chapter is not just about the history of astronomy. As the astronomers of the Renaissance struggled to understand Earth and the heavens, they invented a new way of understanding nature—a way of thinking that is now called science. Every chapter that follows will use the methods that were invented when Copernicus and others grappled with the ancient idea that Earth is the center of the Universe. (Galileo's telescope revealed such things as craters on the Moon, and he explained how that evidence could be used to test the prevailing Earth-centered model of the Universe. He was condemned by the Inquisition in 1633.)
Galileo Galilei, copernican model, not invent, not condemned,
Chapter 3-4 GALILEO GALILEI ______ ___________ was born in the Italian city of Pisa in 1564 and studied medicine at the university there. His true love, however, was mathematics, and he eventually became professor of mathematics at the university at Padua, where he remained for 18 years. During this time, Galileo seems to have adopted the _________ _______, although he admitted in a 1597 letter to Kepler that he did not support that model publicly, fearing criticism. Most people know two "facts" about Galileo, and both are wrong. Galileo did ____ ________ the telescope, and he was ____ ________ by the Inquisition for believing that Earth moved around the Sun. As you learn about Galileo, you will discover that what was on trial were not just his opinions about the place of Earth but also the methods of science itself.
_____ are small icy bodies that orbit the Sun and produce tails of gas and dust when they approach the Sun.
Comets
accurately, uniform circular motion, position, epicycles, elliptical
Copernicus's model was simple and straightforward compared with the multiple off-center circles of the Ptolemaic model. However, De Revolutionibus failed to immediately disprove the geocentric model for one critical reason—the Copernican model could not predict the positions of the planets any more ____________ than the Ptolemaic model could. Although Copernicus proposed a revolutionary idea in making the Solar System heliocentric, he was a classically trained astronomer with great respect for the old concept of uniform circular motion. Copernicus objected to Ptolemy's schemes for moving Earth slightly off-center and varying the speeds of planet motions. That seemed arbitrary and ugly to Copernicus, so he returned to a strong but incorrect belief in ___________ _______________ ____________. Therefore, even though his model put the Sun correctly at the center of the Solar System, it could not accurately predict the ____________ of the planets as seen from Earth. Copernicus even had to reintroduce small ____________ to match minor variations in the motions of the Sun, the Moon, and the planets. Astronomers today recognize those variations as due to the planets' real motions in ______________ orbits (discussed in Section 3-3).
The _____ is radiation from the hot matter of the Universe soon after the big bang
Cosmic Microwave Background
Apparent visual magnitudes
Describe how the stars look to human eyes observing from Earth.
By the time the Universe was about two minutes old, protons and neutrons could link to form _____, the nucleus of a heavy hydrogen atom, and not be broken apart again.
Deuterium
In the context of light curves, observations of an eclipsing binary system can directly tell astronomers not only the masses of its stars but also their _____.
Diameters
The first stage of Earth's evolution is _____.
Differentiation
The observation of the moons of Jupiter by Galileo Galilei suggested that: Earth could not move as its moon would be left behind. Earth could move and keep its moon. the Solar System was actually geocentric. the only center of motion was Earth.
Earth could move and keep its moon.
Which of the following was a belief of Copernicus
Earth rotated on its axis
Claudius Ptolemy created an elaborate geometrical and mathematical model to explain details of the observed motions of the planets while assuming: Earth was motionless at the center of the Universe. there were many galaxies in the Universe. the Sun was at the center of the Universe. Earth was part of a galaxy.
Earth was motionless at the center of the Universe.
Claudius Ptolemy created an elaborate geometrical and mathematical model to explain details of the observed motions of the planets while assuming: Earth was motionless at the center of the Universe. there were many galaxies in the Universe. the Sun was at the center of the Universe. Earth was part of a galaxy.
Earth was motionless at the center of the Universe. Correct. Claudius Ptolemy created an elaborate geometrical and mathematical model to explain details of the observed motions of the planets while assuming Earth was motionless at the center of the Universe.
Claudius Ptolemy created an elaborate geometrically and mathematical model to explain details of the observed motions of the planets while assuming
Earth was motionless at the center of the universe
Which of the following was the most imperfect region according to Aristotle's philosophy? The heavens The center of the Sun Earth's surface Earth's center
Earths Center
Cause of the seasons
Earths axis of rotation is tipped 23.5* from the perpendicular to its orbit.
Precession
Earths rotation happens to be pointed toward a spot near the star Polaris, the north star, and Earth's large mass & rapid rotation keep its axis fixed in space.
_____ is a number between 1 and 0 that describes the shape of an ellipse. Acceleration Eccentricity Momentum Mass
Eccentricity Correct. Eccentricity is a number between 1 and 0 that describes the shape of an ellipse. The eccentricity of an ellipse is the distance from one focus to the center of the ellipse divided by the semi-major axis
Through the year, the Sun moves eastward among the stars following a line called the ___, the apparent path of the Sun among the stars.
Ecliptic
A(n) _____ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant. ellipse deferent equant paradigm
Ellipse
An atom can move an electron to a lower energy level by
Emitting a photon of light
Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the _____ that slid around a larger circle called the deferent. heterocycle pericycle epicycle hemicycle
Epicycle
Which of the following is a Kuiper Belt Object that is quite large and has about the same diameter as Pluto but is 27% more massive?
Eris
The velocity that an object needs to achieve to leave Earth permanently is called its ________ velocity.
Escape
By tradition, any planet in the sunset sky is called a(n) _____. exoplanet pulsar planet morning star evening star
Evening Star
2.14 years, retrograde, east
Every ______ ______, Mars passes through a _____________ loop. Two successive loops are shown here. Each loop occurs further ______ along the ecliptic and has its own shape. (https://www.youtube.com/watch?v=TK9ozJYELR8)
A total lunar eclipse is visible only from the path of totality.
F
A total solar eclipse will be visible from the same location on Earth one saros cycle later.
F
An object in a stable orbit continuously misses Earth because of its vertical velocity. T/F
F
Claudius Ptolemy discovered that the orbit of Mars is an ellipse. T/F
F
During an annular eclipse of the sun, the corona of the sun is visible.
F
Electromagnetic waves with wavelengths shorter than gamma rays are called infrared radiation. T/F
F
If the distance from Earth to the Moon were doubled, the gravitational force between them would increase by a factor of 22, or 4. T/F
F
In the Copernican model, Venus moves around an epicycle centered on a line between Earth and the Sun. T/F
F
In the context of granulation, convection occurs when hot fluid sinks and cool fluid rises. T/F
F
Spiral arms are concentrated at the center of our Galaxy. T/F
F
Spring tides and neap tides are caused solely by the effects of the Sun. T/F
F
The average distance from Venus to the Sun is about 2 AU. T/F
F
The nearest star to the Sun is Sirius. T/F
F
The particles inside a hot object are less agitated than the particles in a cool object. T/F
F
The third quarter moon rises at noon.
F
Which of the following is not one of Newton's Laws of Motion?
For any system closed to all transfers of matter and energy, the mass of the system must remain constant over time. ( this is law of cons. of mass)
Which if the following is true of Claudius Ptolemy?
For him, first principles took second place to accuracy
The merger of galaxies is called _________.
Galactic Cannibalism
interrogated, Bellarmine, forgery, disobeying, confined
Galileo was _________ by the Inquisition and threatened with torture. He must have thought of Giordano Bruno, a monk who was tried, condemned, and burned at the stake in Rome in 1600 for, among other offenses, supporting Copernicus. However, Galileo's trial did not center on his belief in Copernicus's model. Dialogo had been approved by two censors. Rather, the trial centered on a record of the meeting in 1616 between Galileo and Cardinal _________ that included the statement that Galileo was "not to hold, teach, or defend in any way" the principles of Copernicus. Many historians believe that this document, which was signed neither by Galileo nor by Bellarmine nor by a legal secretary, was a ______, or perhaps a draft that was never used. By this time Bellarmine was dead and could not testify about the meeting or the document. The Inquisition condemned Galileo not for heresy but for ________ the orders given him in 1616. In 1633, at the age of 70, kneeling before the Inquisition, Galileo read a recantation admitting his errors. Tradition has it that as he rose he whispered, "E pur si muove" ("Still it moves"), referring to Earth. Although he was sentenced to life imprisonment, he was actually ________ at his villa for the next 10 years, perhaps through the intervention of the pope. He died there in 1642, 99 years after the death of Copernicus.
Any rapid change in a gravitational field should spread outward at the speed of light as expanding waves transporting energy. What is this called?
Gravitational radiation
When Voyager 2 flew by Neptune in 1989, the largest feature observed was the ___, which is roughly the size of Earth.
Great Dark Spot
When Voyager 2 flew by Neptune in 1989, the largest feature observed was the _____, which is roughly the size of Earth.
Great Dark Spot
evidence, reality, tested
HOW DO WE KNOW? EVIDENCE AS THE FOUNDATION OF SCIENCE Why is evidence critical in science? From colliding galaxies to the inner workings of atoms, scientists love to speculate and devise hypotheses, but all scientific knowledge is ultimately based on _________ from observations and experiments. Evidence is _____, and scientists constantly check their ideas against reality. When you think of evidence, you probably think of criminal investigations in which detectives collect fingerprints and eyewitness accounts. In court, that evidence is used to try to understand the crime, but there is a key difference in how lawyers and scientists use evidence. A defense attorney can call a witness and intentionally fail to ask a question that would reveal evidence harmful to the defendant. In contrast, the scientist must be objective and not ignore any known evidence. The attorney is presenting only one side of the case, but the scientist is searching for the truth. In a sense, the scientist must deal with the evidence as both the prosecution and the defense. It is a characteristic of scientific knowledge that it is supported by evidence. A scientific statement is more than an opinion or a speculation because it has been _______ objectively against reality. As you read about any science, look for the evidence in the form of observations and experiments. Every hypothesis or conclusion should have supporting evidence. If you can find and understand the evidence, the science will make sense. All scientists, from astronomers to zoologists, demand evidence. You should, too.
geocentric, heliocentric, paradigm, perceptions, deficiencies, evidence
HOW DO WE KNOW? SCIENTIFIC REVOLUTIONS How do scientific revolutions occur? You might think from what you know of the scientific method that science grinds forward steadily as new hypotheses are tested against evidence and accepted or rejected. In fact, science sometimes leaps forward in scientific revolutions. The Copernican Revolution is often cited as the perfect example; in a few decades, astronomers rejected the 2000-year-old ____________ model and adopted the ______________ model. Why does that happen? It's all because scientists are human. The American philosopher of science Thomas Kuhn has referred to a commonly accepted set of scientific ideas and assumptions as a scientific ______________. The pre-Copernican thinkers shared a geocentric paradigm that included uniform circular motion, geocentrism, and the perfection of the heavens. Although they were intelligent, they were prisoners of that paradigm. A scientific paradigm is powerful because it shapes your _____________. It determines what you judge to be important questions and what you judge to be significant evidence. Consequently, the ancient philosophers could not recognize how their geocentric paradigms limited what they understood. You will see here how the work of Copernicus, Galileo, and Kepler overthrew the geocentric paradigm. Scientific revolutions occur when the ________________ of the old paradigm build up until finally a scientist has the insight to think "outside the box." Pointing out the failings of the old ideas and proposing a new paradigm with supporting _____________ is like poking a hole in a dam; suddenly the pressure is released, and the old paradigm is swept away. Scientific revolutions are exciting because they give you a dramatic new understanding of nature, but they are also times of conflict as new insights sweep away old ideas.
Which of the following is true of Galileo Galilei? He publically defended the geocentric model of the Universe. He invented the telescope. He applied his careful observations of the sky to determine the place of Earth. He was the first person to look at the sky through a telescope.
He applied his careful observations of the sky to determine the place of Earth. Correct. Galileo Galilei was the first person to observe the sky carefully and apply his observations to the main theoretical problem of the day—the place of Earth.
Which of the following is true of Johannes Kepler ?
He discovered that the orbit of Mars is an ellipse not a circle
Who devised the magnitude scale?
Hipparchus
Magnitude Scale
How astronomers measure the brightness of stars.
Light year
How far light travels in one year Light that is 60 light years away would take 60 years to reach us
Which of the following let's you conclude that a compact object cannot be a neutron star and that it must be a black hole
If the mass of the compact object is greater than about 3 solar masses
far, unchanging, measuring, Kepler
In 1572, astronomers were startled to see a new star (now called Tycho's supernova) appear in the sky. Aristotle had argued that the heavens were perfect and therefore unchanging, so astronomers concluded that the new star had to be nearer than the Moon. Tycho could not detect the new star's parallax (look back to Concept Art 3A), meaning it had to be ______ beyond the Moon; it was a change in the supposedly ______________ starry sphere. When Tycho wrote a book about his discovery, the king of Denmark honored him with a generous income and the gift of an island, Hveen, where Tycho built a fabulous observatory. Tycho lived before the invention of the telescopes, so his observatory was equipped with wonderful instruments for _____________ the positions of the Sun, the Moon, and the planets using the unaided eye and peering along sights. For 20 years, Tycho and his assistants carefully tracked the motions of the planets. After the death of the Danish king, Tycho moved to Prague where he became the Imperial Mathematician to the Holy Roman Emperor Rudolph II. Tycho hired a few assistants including a German school teacher named Johannes _________. Just before Tycho died in 1601, he asked Rudolph II to make Kepler Imperial Mathematician.
Which of the following statements is true of medium-mass stars?
In such stars, the helium ash accumulates in an inert helium core surrounded by unprocessed hydrogen.
Which of the following forms of electromagnetic radiation has a longer wavelength than visible light?
Infrared radiation
Which of the following forms of electromagnetic radiation has a longer wavelength than visible light? Ultraviolet radiation Infrared radiation Gamma rays X-rays
Infrared radiation Correct. Infrared radiation has longer wavelengths than the maximum wavelength of visible light. The wavelength of infrared radiation ranges from 700 nanometers to about 1 millimeter.
Which of the following statements is true of the solar wind?
It can be considered an extension of the corona.
Which of the following statements is true of the chromosphere?
It can be seen during a total solar eclipse.
Which of the following statements is true of the first reaction in the proton-proton chain?
It emits a positron
Which of the following statements is true of Jupiter?
It has a slightly flattened shape.
Which of the following statements is true of Uranus when compared with Jupiter or Saturn?
It has much less heat flowing out of its interior than Jupiter or Saturn.
Which of the following is true of Mercury?
It has negligible atmosphere
Which of the following is true of Mercury?
It has negligible atmosphere.
Which of the following statements is true of the dynamo effect?
It is believed to operate in the liquid metal of Earth' core to produce Earth's magnetic field
Which of the following statements is true of the dynamo effect?
It is believed to operate in the liquid metal of Earth's core to produce Earth's magnetic field.
Which of the following statements is true of Jupiter's interior?
It is composed of a material that is a very good conductor of electricity.
Which of the following is true of the Moon's synodic period?
It is longer than the Moon's sidereal period.
Which of the following statements is true of interstellar dust
It is made mostly of carbon and silicates mixed with frozen water.
Which of the following is true of Mars's atmosphere?
It is mostly composed of carbon dioxide
Which of the following is true of a first principle ?
It is something that seems obviously true and needs no further examination
Which of the following is true of a first principle?
It is something that seems obviously true and needs no further examination
Which of the following is true of a first principle? It is something that is true but needs a lot of examination to be proven true. It is something that is false but appears true without proper examination. It is something that seems obviously true and needs no further examination. It is something that is obviously false and needs no further examination.
It is something that seems obviously true and needs no further examination.
What is true of Sagittarius A
It is supermassive black hole
Which of the following statements is true of absolute zero?
It is the temperature at which an object contains no thermal energy that can be extracted
Which of the following statements is true of absolute zero?
It is the temperature at which an object contains no thermal energy that can be extracted.
Which of the following is true of chromatic aberration
It occurs when different colors are focus at slightly different distances
Which of the following is true of chromatic aberration?
It occurs when different colors are focused at slightly different distances.
Which of the following is true of chromatic aberration? It is the main cause of seeing. It mostly occurs in reflecting telescopes. It occurs when different colors are focused at slightly different distances. It is a natural phenomenon that occurs because of high turbulence in Earth's atmosphere.
It occurs when different colors are focused at slightly different distances. Correct. Chromatic aberration is a distortion found in refracting telescopes because lenses focus different colors at slightly different distances. Images are consequently surrounded by color fringes. When light is refracted through glass, shorter wavelengths bend more than longer wavelengths. As a result, you see a color blur around every image. This color separation is called chromatic aberration, and it can be only partially corrected.
Which of the following is true of the Ptolemaic model of the universe ?
It predicted the positions of the planets with fair accuracy at first
Which of the following statements is true of the apparent magnitude scale that refers to stellar apparent brightness?
It tells you how bright stars appear to you on Earth.
Which of the following indicates that the sun must be gas from its surface to its center
It's low density high temperature
Why are eclipses visible from planet Earth?
Its about occultations not shadows.
Which of the following is true of Venus?
Its atmosphere is mostly composed of carbon dioxide
Which of the following indicated that the Sun must be gas from its surface to its center?
Its low density and high temperature
Which of the following indicates that the Sun must be gas from its surface to its center? Its hot spots on the photosphere Its low density and high temperature Its weak magnetic field and small diameter Its limited gravitational force
Its low density and high temperature
Astronomers try to reconstruct our Galaxy's past from _____.
Its spherical component.
Jupiter's center appears to have a rocky core. In this context, the term rocky core refers to:
Jupiter's chemical composition
ellipses, sun, areas, time, proportional, ellipses, circular, Mercury
Kepler's Laws of Planetary Motion: 1)The orbits of the planets are ____________ with the ______ at one focus. 2) A line from a planet to the Sun sweeps over equal _______ in equal intervals of _______. 3) A planet's orbital period squared is _____________ to its average distance from the Sun cubed: P^2y(years)=a^3AU P (orbital period)= time planet takes to travel around the Sun once P to the 2nd power (y= tears) A (semi-major axis of a planet's orbit)= average distance from the Sun= the Semi-Major axis A to the third power (AU= astronomical units) Kepler's first law states that the orbits of the planets around the Sun are ______ with the Sun at one focus. Thanks to the precision of Tycho's observations and the sophistication of Kepler's mathematics, Kepler was able to recognize the elliptical shape of the orbits even though they are nearly _______. Of the planets known to Kepler, __________ has the most elliptical orbit, which you can measure in Figure 3-7, but even it deviates only slightly from a circle. (The orbits of the planets are nearly circular. You can measure the horizontal and vertical diameters of this orbit to detect its elliptical shape.)
closer, rapidly, farther, same
Kepler's second law states that a line from the planet to the Sun sweeps over equal areas in equal intervals of time. This means that when the planet is _______ to the Sun and the line connecting it to the Sun is shorter, the planet moves more _______ to sweep over the same area that is swept over when the planet is farther from the Sun. Thus the planet in Figure 3-6c would move from point A′ to point B′ in one month, sweeping over the area shown. But when the planet is ________ from the Sun, one month's motion would be shorter, from A to B although the total area swept out is the _______.
_____ is absorbed by water vapor in Earth's lower atmosphere. Long-wavelength infrared radiation Long-wavelength ultraviolet radiation X-ray radiation Radio wave radiation
Long-wavelength infrared radiation Correct. Water vapor in Earth's lower atmosphere absorbs long-wavelength infrared radiation. Only visible light, some short-wavelength infrared radiation, and some radio waves reach Earth's surface through what are called atmospheric windows.
Mars has very different surface features than Earth. What aspect of mars was MOST important in its developing so differently from Earth
Mars mass
Which of the following planets has the highest uncompressed density?
Mercury
___ is the closest planet to the Sun.
Mercury
Which is the correct order of the planets, moving from closest to the Sun to farthest from the Sun?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
In astronomical usage all atoms are heavier than helium are referred to as
Metals
The hazy band of light that circles our sky.
Milky Way
____ occur when the Moon is in the first or third quarter of its lunar cycle. Total solar eclipses Neap tides Spring tides Annular eclipses
Neap tides Correct. At first- and third-quarter moons, solar tides cancel out part of lunar tides so that high and low tides are not extreme. These are called neap tides.
Which of the following is most likely to occur when an observer finds a star moving perpendicular to his or her line of sight?
Neither a blueshift nor a redshift occurs.
One of the giant ice giants of the solar system
Neptune
Which of the following objects is a part of the Solar System? Coku Tau/4 Sirius Neptune Procyon
Neptune
which of the following objects is a part of the solar system ?
Neptune
The short pulses and the discovery of the pulsar in the Crab Nebula are strong evidence that pulsars are ___.
Neutron Stars
Circumpolar constellation
Never rise or set
In the context of Uranus's rings, the passage of the planet in front of a star is referred to as a(n) ___.
Occultation
distance, decreases, square, increases, inverse square relation, attracting, objects, time, square, distance
Newton also realized that the _______ between the objects is important. The gravitational force between two bodies depends not only on the masses of the bodies but also on the distance between them. He recognized that the force of gravity ________ as the ________ of the distance between the objects ________. Specifically, if the distance from, say, Earth to the Moon were doubled, the gravitational force between them would decrease by a factor of 2^2, or 4. If the distance were tripled, the force would decrease by a factor of 3^2, or 9. This relationship is known as the ________ _______ _________. Newton guessed that gravity works by an inverse square relation because he had already discovered that light behaves this way (to be discussed in more detail in Chapter 9). To summarize, the force of gravity __________ two _________ to each other equals a constant ________ the product of their masses divided by the ________ of the __________ between the objects. Gravity is universal: Your mass affects the planet Neptune and the galaxy M31, and every other object in the Universe, and their masses affect you—although not much, because they are so far away and your mass is relatively very small.
Are meteors stars?
No
Could Copernicus' universe model predict the positions of the planets better than Ptolemy's model?
No
Did Galileo discover the telescope?
No
Zodiac
Not the serial killer, but the path the planets follow
Nuclear power plants on Earth generate energy through ___.
Nuclear fission reactions
Nuclear power plants on Earth generate energy through _____. -
Nuclear fission reactions
___ are reactions that join the nuclei of atoms to form more massive nuclei.
Nuclear fusion reactions
____ are reactions that join the nuclei of atoms to form more massive nuclei
Nuclear fusion reactions
Which of the following statements is true of the spectral sequence
O stars are the hottest, and M stars are the coolest.
Which of the following is the correct spectral sequence of stars from hottest to coolest?
OBAFGKM
_____________ are made using your senses or scientific equipment.
Observations
The creation of a planetary atmosphere from a planet's interior is called
Outgassing
The large oval grooves found on Uranus's moon Miranda that indicate past geological activity are known as ___.
Ovoids
__________is the term that refers to the common experience of an apparent shift in the position of a foreground object due to a change in the location of the observer's viewpoint.
Parallax
A ___ is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength
Photon
A non luminous body that is massive enough to be spherical and to have cleared its orbital path.
Planet
___ is an expanding shell of gas ejected from a medium-mass star during the latter stages of its evolution.
Planetary Nebula
Solar nebula theory supposes that
Planets form in rotating disks of gas and dust around young stars
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune (My Very Excellent Mother Just Sent Us Nachos)
Planets in order
is the nearest star to the Sun
Proxima Centauri
The study of the behavior of atoms and atomic particles is referred to as:
Quantum Mechanics
Which of the following is true of quasars?
Quasar eruptions became less common as galaxies became more stable.
_____ are the most distant visible objects in the Universe.
Quasars
Among the following electromagnetic waves, photons of which electromagnetic radiations carry the lowest energy? Radio waves Visible light Gamma rays Ultraviolet
Radio waves Correct. The amount of energy a photon carries depends on its wavelength. Shorter-wavelength photons carry more energy, and longer-wavelength photons carry less energy. Radio waves have the longest wavelengths among the rest of the electromagnetic radiation; therefore, the photons of radio waves carry less energy than any other electromagnetic radiation.
Which of the following statements is true in the context of the visible light spectrum?
Red light has the longest wavelength that can be seen by the average human eye.
Which of the following statements is true in the context of visible light spectrum?
Red light has the longest wavelength that can be seen by the average human eye.
In the context of blackbody radiation, which of the following statements is true of stars?
Red stars are cool, and blue stars are hot.
Which of the following statements is true of stars
Red stars are cool, blue are hot
Radio telescopes are _____.
Reflecting telescopes
__ refers to the ability of a telescope to reveal fine detail.
Resolving power
____ refers to the ability of a telescope to reveal fine detail.
Resolving power
_____ refers to the ability of a telescope to reveal fine detail. Focal length Magnifying power Spherical aberration Resolving power
Resolving power Correct. Resolving power refers to the ability of a telescope to reveal fine detail. All else being equal, telescopes with larger diameter primary mirrors have better resolving power. As radio telescopes measure longer wavelengths, they have less resolving power than optical telescopes of the same size.
The occasional backward motion of the planets against the background of fixed stars is called _____. oscillation retrograde motion anterograde motion rotation
Retrograde Motion
The occasional backward motion of the planets against the background of fixed stars is called
Retrograde motion
___________ is the motion of a body around a point outside the body.
Revolution
Horoscope
Shows the location of the sun, moon, and planets among the zodiacal signs with respect to the horizon at the moment of a person's birth as seen from that longitude & latitude.
The time taken by the moon to circle the sky once and return to the same position among the stars is known as the moons _____
Sidereal period
questioned, inquisition, certain statements, hypotheses
Sidereus Nuncius was popular and made Galileo famous. In 1611, Galileo visited Rome and was treated with great respect. He had friendly discussions with the powerful Cardinal Barberini, but because he was outspoken, forceful, and sometimes tactless he offended other important people who ________ his telescopic discoveries. Some critics said he was wrong, and others said he was lying. Some refused to look through a telescope lest it mislead them, and others looked and claimed to see nothing (hardly surprising given the awkwardness of those first telescopes). When Galileo visited Rome again in 1616, Cardinal Bellarmine interviewed him privately and ordered him to cease public debate about models of the Universe, an order Galileo appears to have mostly followed. The _________ (renamed in the 20th century the Congregation of the Holy Office) banned books relevant to the Copernican hypothesis, although De Revolutionibus itself was only suspended pending revision because it was recognized as useful for its predictions of planet positions. Everyone who owned a copy of the book was required to cross out _____ ________ and add handwritten corrections stating that Earth's motion and the central location of the Sun were only ________ and not facts, a situation that you will recognize as recurring today in connection with textbooks discussing biological evolution.
What is an object of zero radius and infinite density?
Singularity
The event that occurs when the Moon passes directly between the Earth and the Sun
Solar eclipse
___ is the event that occurs when the Moon passes directly between Earth and the Sun, blocking your view of the Sun.
Solar eclipse
Which of the following statements is true of white dwarfs...
Some are among the hottest known stars
Issac Newton concluded that a force from Earth had to act on the Moon because
Some force is needed to accelerate the Moon toward Earth
Isaac Newton concluded that a force from Earth had to act on the Moon because:
Some force is needed to accelerate the Moon toward Earth.
Which of the following statements is true of white dwarfs?
Some of them are among the hottest stars known.
Which of the following statements is true of Kuiper Belt Objects?
Some of them have moons on their own
What are asteroids examples of?
Space Debris
The arrangement of stars in a temperature sequence from hot to cold.
Spectral sequence
A _____ is a device that separates light by wavelength to produce a spectrum
Spectrograph
A galaxy undergoing a rapid burst of star formation.
Starburst Galaxy
The H-R diagram can help you understand different kinds of
Stars
Summer solstice
Sun at it's farthest point north
Nicolaus Copernicus devised a heliocentric universe model. What does heliocentric mean?
Sun centered
Vernal equinox
Sun crosses the celestial equator going northward at the point
The relatively dark spots on the sun that contains intense magnetic fields are called ___.
Sunspots
In 1592, astronomers noticed something peculiar in the sky. Tycho noted that it had to be very far away because he could not detect its parallax. What did the astronomers see in the sky?
Supernova
An eclipse season is the interval during which the sun crosses a node of the moon's orbit.
T
If you were on the moon during a total lunar eclipse, the sun would be hidden behind Earth.
T
To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant (T or F)
TRUE
The opacity of a gas depends strongly on its _____.
Temperature
The moons of Jupiter supported what model of the Universe over the Ptolemaic model.
The Copernican model
__________is the process by which an atmosphere traps heat and raises the temperature of a planetary surface.
The Greenhouse Effect
___ coincides with the period called the "Little Ice Age," a time of unusually cool weather in Europe and North America.
The Maunder Minimum
is the hazy band of light that circles our sky, produced by the glow of our galaxy
The Milky Way
Which of the following is true of the Moon orbiting Earth?
The Moon orbits eastward around Earth once a month
Which of the following is true of the Moon orbiting Earth?
The Moon orbits eastward around Earth once a month.
Which of the following seems to be a region of self-sustaining star formation?
The Orion Complex
In the context of the Sun's surface, which of the following is the source of most of the sunlight received by Earth?
The Photosphere
In the context of the stars in binary systems, which of the following statements is true of the Roche lobes?
The Roche lobes can interfere with the evolution of the stars that are close together.
_______ is an 18 year, 11 day period after which the pattern of lunar and solar eclipses repeats
The Saros cycle
Which if the following stars is part of the Solar System?
The Sun
Which of the following is an example of a star?
The Sun
Which of the following stars is part of the solar system?
The Sun
tides, smaller, extra high, extra low, neap tide, tidal bulges, friction, moon, same side, orbits, forward, 4 cm
The Sun also produces __________ on Earth, although they are ___________ than lunar tides. At new and full moons, the lunar and solar tides add together to produce ________ ________ and _______ _______ tides that are called spring tides. At first- and third-quarter moons, the solar tides cancel out part of the lunar tides so that high and low tides are not extreme (see Figure 3-12a). These are called ________ ________. Although the oceans flow easily into ________ _______, the nearly rigid bulk of Earth flexes into tidal bulges and the plains and mountains rise and fall a few centimeters twice a day. ____________ is gradually slowing Earth's rotation, and fossil evidence shows that Earth used to rotate faster. In the same way, Earth's gravity produces tidal bulges in the _________, and, although the Moon used to rotate faster, friction has slowed it down and it now keeps the _________ ________ facing Earth. Tides can also affect _________. The rotation of Earth drags the tidal bulges slightly ahead of the Moon, and the gravitation of the bulges of water pull the Moon _________ in its orbit. This makes the Moon's orbit grow larger by about __ ___ a year, an effect that astronomers can measure by bouncing lasers off reflectors left on the Moon by the Apollo astronauts. Spring tides (are extreme) occur when the Sun and moon add together (Full and new moon) Neap tides (are mild) occur when tides caused by the Sun and the Moon partially cancel (first and third quarter) friction with ocean beds slow earth and drags its tidal bulges slightly ahead. Gravity of tidal bulges pulls moon forward and alters its orbit
Which of the following statements is true of a Doppler shift? A light source approaching an observer will appear red. A light source moving away from an observer will appear blue. The shift in the velocity of the source is identified irrespective of its direction. The amount of change in wavelength depends on the speed of the source.
The amount of change in wavelength depends on the speed of the source.
Ecliptic
The apparent path of the sum in its yearly motion around the sun. The projection of earths orbit on the sky or the plane of earths orbit.
Magnitude scale
The astronomical brightness scale. The larger the number, the fainter the star.
Which of the following is a reason why the Ptolemaic model was the accepted model of the Universe? The authority of Aristotle was immense. It proved that the Sun was at the center of the Universe. It was a very good predictor of planet positions. The multiple revisions to the model made it completely accurate.
The authority of Aristotle was immense. Correct. In spite of many revisions, the Ptolemaic model was still a poor predictor of planet positions, but because of the authority of Aristotle, it was the almost universally accepted model.
Which of the following is a reason why the Ptolemaic model was the accepted model of the Universe?
The authority of aristotle was immense
Which of the following features of a telescope determines its light gathering power?
The diameter of the primary mirror
Which of the following features of a telescope determines its light-gathering power?
The diameter of the primary mirror
____ is the site of most of the star formation in the Milky Way galaxy
The disk component
Copernican revolution
The dramatic change, initiated by copernicus, that occurred when we learned that Earth is a planet orbiting the Sun rather than the center of the universe -The problem of the place of Earth was resolved
In the context of the magnitude scale, the larger the magnitude number of a star___
The fainter the star is
semi-major axis, a, half, longest, shape, half, foci, one, elongated, zero, circular, zero, farther, flatter, one, natural laws
The geometry of an ellipse is described by two simple numbers. The _____-_______ ______, __, is ____ of the ________ diameter (Figure 3-6b). The eccentricity, e, of an ellipse is half the distance between the ____ divided by the semi-major axis. The eccentricity of an ellipse tells you its ______: If e is nearly equal to _____, the ellipse is very ____________; if e is close to ______, the ellipse is more ________. To draw a circle with the string and tacks shown in Figure 3-6a, you would move the two thumbtacks together, which shows that a circle is the same as an ellipse with eccentricity equal to ________. As you move the thumbtacks _________ apart, the ellipse becomes ________, and the value of its eccentricity moves closer to ________. Kepler used ellipses to describe the motion of the planets in three fundamental rules that have been tested and confirmed so many times that astronomers now refer to them as "___________ ________." They are commonly called Kepler's laws of planetary motion, summarized in Table 3-1 (See How Do We Know?.).
___ says that the amount of energy flowing out of the top of a layer in the star must be equal to the amount of energy coming in at the bottom, plus whatever energy is generated within the layer.
The law of conservation of energy
___ says that the total mass of a star must equal the sum of the masses of its shells.
The law of conservation of mass
___ says that energy must flow from hot regions to cooler regions either by conduction, convection, or radiation.
The law of energy transport
In stellar astronomy, _____ states that the weight of each layer of a star must be supported by the layer below
The law of hydrostatic equilibrium
_____ is a unit of distance equal to the distance light travels in 1 year.
The light year
is a unit of distance equal to the distance light travels in 1 year
The light-year
___ is the small cluster of a few dozen galaxies that contains our Milky Way Galaxy.
The local group
copernican, earth could not move, jupiter, centers of motion, shortest, longer, sun, phases, crescent, complete set, revolved
The moons of Jupiter supported the _______ over the Ptolemaic model. Critics of Copernicus had said _____ ______ ___ ____ because the Moon would be left behind; but Jupiter moved and kept its satellites. Galileo's discovery suggested that Earth, too, could move and keep its Moon. Also, Aristotle's philosophy included the belief that all heavenly motion was centered on Earth. Galileo showed that Jupiter's moons revolve around _______, so there could be _______ ___ _______ other than Earth. Later, after the Messenger was published, Galileo noticed that Jupiter's inner-most moon had the ________ orbital period and the moons farther from Jupiter had proportionally ______ periods. In this way, Jupiter's moons made up a harmonious system ruled by Jupiter, just as the planets in the Copernican universe were a harmonious system ruled by the ____. This similarity didn't constitute proof, but Galileo saw it as an indication that the Solar System could be Sun centered and not Earth centered. In the years of further exploration with his telescope, Galileo made additional fundamental discoveries (Figure 3-9). When he observed Venus, Galileo saw that it was going through _______ like those of the Moon. In the Ptolemaic model, Venus moves around an epicycle centered on a line between Earth and the Sun. If that were true, it would always be seen as a _______, like the model in Figure 3-10a. But Galileo saw Venus go through a _______ ___ of phases, including full and gibbous, which proved that it did indeed ________ around the Sun (Figure 3-10b). ((a) Galileo is remembered as the great defender of Copernicanism. (b) Two of Galileo's telescopes, on display in a museum in Florence. Although he did not invent telescopes, Galileo will always be associated with them because they were the source of much of the observational evidence he used to try to understand the Universe.) ((a) Galileo is remembered as the great defender of Copernicanism. (b) Two of Galileo's telescopes, on display in a museum in Florence. Although he did not invent telescopes, Galileo will always be associated with them because they were the source of much of the observational evidence he used to try to understand the Universe.)
move, universe
The most important consequence of the Copernican hypothesis was not what it said about the Sun but what it said about Earth. By placing the Sun at the center, Copernicus made Earth ______ along an orbit like the other planets. By making Earth a planet, Copernicus revolutionized humanity's view of its place in the ____________ and triggered a controversy that would eventually bring the astronomer Galileo Galilei before the Inquisition, a controversy over the nature of scientific and religious truths that continues even today.
Which of the following was discovered by Galileo Galilei? The other galaxies in the Universe The mountains and valleys on the surface of the Moon The planets Uranus and Neptune The planets being in elliptical motion around the Sun
The mountains and valleys on the surface of the Moon
Which of the following was discovered by Galileo Galilei? The mountains and valleys on the surface of the Moon The other galaxies in the Universe The planets Uranus and Neptune The planets being in elliptical motion around the Sun
The mountains and valleys on the surface of the Moon Correct. Galileo Galilei discovered that the Moon was not perfect. It had mountains and valleys on its surface, and Galileo used the shadows to calculate the height of the mountains.
Which of the following was discovered by Galileo Galilei?
The mountains and valleys on the surface of the moon
What is a result of earth rotating on its axis?
The occurrence of day and night
Which of the following is a result of Earth rotating on its axis?
The occurrence of day and night
perigee
The orbital point of closest approach to earth
apogee
The orbital point of greatest distance from earth
_____ is a series of three nuclear reactions that builds a helium nucleus by adding protons one at a time.
The proton-proton chain
umbra
The region of a shadow that is totally shaded
Which of the following is true of early astronomers?
The thought the entire Universe consisted of Earth, the Sun, the Moon, and the five other planets
once, P, distance, sun, semi-major axis, a, related, empirical, why, held, around
The time that a planet takes to travel around the Sun _____ is its orbital period, ___, and its average ________ from the _____ equals the _____-_____ _____ of its orbit, ___. Kepler's third law tells us that these two quantities, orbital period and semi-major axis, are ________: Orbital period squared is proportional to the semi-major axis cubed. For example, Jupiter's average distance from the Sun (which equals the semi-major axis of its orbit) is 5.2 AU. The semi-major axis cubed would be about 140.6, so the period must be the square root of 140.6, roughly 11.9 years. P^2y(years)=a^3AU P^2y=5.2^3AU P^2y=140.6AU Py=√140.6 P=11.9 years It is important to notice that Kepler's three laws are _________. That is, they describe a phenomenon without explaining _____ it occurs. Kepler derived them from Tycho's extensive observations without referring to any first principles, fundamental assumptions, or theory. In fact, Kepler never knew what ______ the planets in their orbits or why they continued to move ________ the Sun in the ways he discovered.
Which of the following is true of Seyfert galaxies?
The spectra of their nuclei contain broad emission lines of highly ionized atoms.
Which of the following is true of the scientific names of constellations?
They are in latin or greek
Which of the following is true of poor galaxy clusters?
They are irregularly shaped
Identify a true statement about asterisms and constellations.
They are made up of stars that are not physically associated with one another.
Which of the following is true of the signs of the zodiac?
They are no longer important in astronomy
Which of the following is true of the signs of the zodiac?
They are no longer important in astronomy.
Which of the following is true of stony meteorites?
They are silicate masses.
Which of the following is true of asteroids?
They are small rocky worlds
Which of the following is true of first-magnitude stars?
They are the stars with the greatest flux
Which of the following is true of first-magnitude stars?
They are the stars with the greatest flux.
Which of the following is true of ancient astronomers
They believed that the sky was a great sphere surrounding Earth
Which of the following is true of ancient astronomers?
They believed that the sky was a great sphere surrounding Earth.
Which of the following statements is true of stars?
They die when they exhaust their fuel, allowing gravity to take control.
Signs of the Zodiac
They divided this band into 12 segments named for the constellations along the ecliptic.
Which of the following statements is true regarding the stars in a stellar association?
They drift away from each other in a few million years.
Which of the following is a reason why low-mass stars cannot get very hot when they contract?
They have limited gravitational energy
Which of the following statements is true of giant stars?
They have more surface area than main-sequence stars of the same temperature
Which of the following statements is true of type I supernovae?
They have no hydrogen lines in their spectra.
Which of the following statements is true of red dwarfs
They have very little weight to support
Identify a true statement about planets
They shine by reflecting sunlight
In the context of the electromagnetic spectrum, which of the following forms of electromagnetic radiation has a shorter wavelength than the shortest wavelength of visible light
Ultraviolet light
In the context of the electromagnetic spectrum, which of the following forms of electromagnetic radiation has a shorter wavelength than the shortest wavelength of visible light?
Ultraviolet light
In the context of the electromagnetic spectrum, which of the following forms of electromagnetic radiation has shorter wavelength than the shortest wavelength of visible light?
Ultraviolet light
___ is absorbed by the layer of ozone in Earth's atmosphere at an altitude of about 20 mi above Earth's surface.
Ultraviolet radiation
_____ is absorbed by a layer of ozone in Earth's atmosphere at an altitude of about 20 mi above Earth's surface.
Ultraviolet radiation
_____ is absorbed by a layer of ozone in Earth's atmosphere at an altitude of about 20 mi above Earth's surface. Infrared radiation X-ray radiation Ultraviolet radiation Microwave radiation
Ultraviolet radiation Correct. Gamma rays, X-rays, and some radio waves are absorbed high in Earth's atmosphere, and a layer of ozone at an altitude of about 20 mi absorbs almost all ultraviolet radiation. Water vapor in the lower atmosphere absorbs long-wavelength infrared radiation.
The region of a shadow that is totally shaded is known as the ___.
Umbra
The region of a shadow that is totally shaded is known as what?
Umbra
Which of the following planets can be seen as a crescent from Earth?
Venus
Galileos observations pf the complete set of the phases of Venus proved that
Venus orbited the sun
What aspect of Venus was MOST important in its developing differently than Earth
Venus's distance from the sun
humanity, planets, nature, fundamental laws, motions,
WHAT ARE WE? THINKERS The scientific revolution began when Copernicus made ____________ part of the Universe. Before Copernicus, people thought of Earth as a special place different from any of the objects in the sky, but in trying to explain the motions in the sky, Copernicus made Earth one of the _________. Galileo and those who brought him to trial understood the significance of making Earth a planet. It made Earth and humanity part of _________, part of the Universe. Kepler showed that the planets move according to simple rules. We are not in a special place ruled by mysterious planetary forces. Earth, the Sun, and all of humanity are part of a Universe in which motions can be described by a few _______________ ______. If simple laws describe the _________ of the planets, then the Universe is not ruled by mysterious influences as in astrology or the whims of the gods atop Mount Olympus. And if the Universe can be described by simple rules, then it is open to scientific study. Before Copernicus, people felt they were special because they thought they were at the center of the Universe. Copernicus, Kepler, and Galileo showed that we are not at the center but nevertheless are part of an elegant and complex Universe. Astronomy tells us that we are special because we can study the Universe and eventually understand what we are. It also tells us that we are not only part of nature; we are the part of nature that can think about nature.
Which of the following is true of visible light?
Wavelength increases from violet light to red light
Which of the following is true of visible light?
Wavelength increases from violet light to red light.
In absolute visual magnitude, Mv, the subscript V refers to the:
Wavelengths of light your eyes can see
The largest fully steerable radio telescope is in _____. California Alaska New Mexico West Virginia
West Virginia
The Sun reaches its most southern point at the _____. winter solstice vernal equinox summer solstice autumnal equinox
Winter Solstice
The Sun reaches its most southern point at the ___.
Winter solstice
inaccurate, uniform circular motion, heliocentric, simplicity, symmetry, same
You should notice the difference between the Copernican model and the Copernican hypothesis. The Copernican model is ____________. It includes __________ _____________ ____________and thus does not precisely describe the motions of the planets. But the Copernican hypothesis that the Solar System is ______________ is correct—the planets do circle the Sun, not Earth. Why that hypothesis gradually won acceptance is a question historians still debate. There are probably a number of reasons, including the revolutionary spirit of the times, but the most important factor may be the ___________ of the idea. For one thing, placing the Sun at the center of the Universe produced a _____________ among the motions of the planets that is elegant, pleasing to the eye and mind (Figure 3-3). In the Ptolemaic model, Mercury and Venus had to be treated differently from the rest of the planets: Their epicycles had to remain centered on the Earth-Sun line. In Copernicus's model, all of the planets were treated the __________. They all followed orbits that circled the Sun at the center.
mass
______- A measure of the amount of matter making up an object.
first principles
_______ _________-Something that seems obviously true and needs no further examination. the self-evident truths, as explained by Aristotle
inverse square relation
________ _________ ________- A rule that the strength of an effect (such as gravity) decreases in proportion as the distance squared increases. the force of gravity decreases as the inverse square of the distance separating the objects
theory
________- A system of assumptions and principles applicable to a wide range of phenomena that has been repeatedly verified.
weight
________- The force that gravity exerts on an object.
natural law
_________ _____- A theory that has been so well confirmed that it is almost universally accepted as correct.
open orbit
_________ _________- An orbit that carries an object away, never to return to its starting point.
empirical
__________- Description of a phenomenon without explaining why it occurs.
spring tides
___________ _________- Ocean tide of large range that occurs at full and new moon. Note that the term "spring" refers to leaping, not to the season of spring.
neap tides
___________ _________- Ocean tide of small range occurring at first- and third-quarter moon.
center of mass
____________ ___ ________- The balance point of a body or system of masses. The point about which a body or system of masses rotates in the absence of external forces.
closed orbits
____________ _________- An orbit that repeatedly returns to the same starting point.
circular velocity
____________ ___________- The velocity an object needs to stay in orbit around another object. the velocity needed to achieve a circular orbit
hypothesis
____________- A conjecture, subject to further tests, that accounts for a set of facts.
heliocentric universe
_____________ ____________- A model universe with the Sun at the center, such as the Copernican universe.
escape velocity
_____________ ____________- The initial velocity an object needs to escape from the surface of a celestial body. (the velocity needed to escape a body's gravitational pull)
uniform circular motion
_____________ _____________ _______________- The classical belief that the perfect heavens could move only by the combination of uniform motion along circular orbits. the movement of an object at a constant speed around a circle with a fixed radius the motion of an object in a circular path at constant speed
geocentric universe
_____________ ______________- A model universe with Earth at the center, such as the Ptolemaic universe.
geocentric universe
_____________ _______________- A model universe with Earth at the center, such as the Ptolemaic universe. the idea that planets revolved in perfect circular orbits around the earth in the universe
ellipse
_____________- A closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant.
deferent
_____________- In the Ptolemaic model of the Solar System, the large circle around Earth along which the center of an epicycle moved.
equant
_____________- In the Ptolemaic model of the Solar System, the point off-center in a deferent from which the center of an epicycle appears to move uniformly.
parallax
_____________- The apparent change in position of an object due to a change in the location of the observer. Astronomical parallax is measured in seconds of arc. An apparent shift in the position of an object when viewed from different locations
retrograde
______________- The apparent backward (westward) motion of planets as seen against the background of stars.
eccentricity, e
_________________, ___- A number between 1 and 0 that describes the shape of an ellipse; the distance from one focus to the center of the ellipse divided by the semi-major axis. e=c/a c- the distance from one focus to center a- half the longest diameter (center to one side)
A dime is 1.8 cm in diameter. Earth's moon is 3.844x1010 cm from Earth and has a diameter of 3.76 x 108 cm. At what distance from your eye would you have to hold a dime so that it has the same angular diameter as the full moon? a. 200 cm b. 2 cm c. 0.2 cm d. 2 AU e. 2 LY
a
A solar or lunar eclipse will occur a. when the sun is near the line of nodes of the moon, and the moon is new or full. b. any time the moon is new or full. c. when the sun is near the solstice, and the moon is new or full. d. half-way through an eclipse year. e. when the sun is near the equinox, and the moon is new or full.
a
The __________ moon is visible above the western horizon a couple of hours before sunrise. a. waning gibbous b. waxing gibbous c. waxing crescent d. waning crescent e. new
a
The first quarter moon rises a. at about noon. b. at sunset. c. at sunrise. d. at about midnight. e. during the second week of each calendar month.
a
Zodiac
a band 18* wide centered on the ecliptic, as the highway the planets follow.
Which of the following is the centerpiece in the unified model of active galactic nuclei (AGN) and quasars?
a black hole
Newtons first law
a body continues at rest or in uniform motion unless acted on by outside force =moon would continue straight unless force accelerated it to earth
Newtons Second Law
a body's change of motion is proportional to the force acting on it, and is in the direction of the force f = ma = force an object exerts comes from its mass and acceleration
Kepler's second law of planetary motion states that: a planet moves at its greatest speed when it is closest to the Sun. the more massive a planet is, the more its speed will be. the mass of a planet determines how far the planet is from the Sun. all the planets move around Earth in elliptical orbits.
a planet moves at its greatest speed when it is closest to the Sun. Correct. Kepler's second law of planetary motion states that a line from a planet to the Sun sweeps over equal areas in equal intervals of time. This means that when the planet is closer to the Sun and the line connecting it to the Sun is shorter, the planet moves more rapidly to sweep over the same area that is swept over when the planet is farther from the Sun.
37. The average distance from Venus to the Sun is _____.
a. 0.7 AU
30. The average distance from Earth to the Sun is _____.
a. 1 AU
51. Light from the Sun reaches Neptune in more than _____.
a. 4 hours
55. Humans have existed on Earth for about _____.
a. 4 million years
32. Which of the following is true of the Sun?
a. It is a self-luminous body of hot gas.
23. _____ is a method for expressing very large or very small numbers by using powers of 10.
a. Scientific notation
47. A _____ is a large system of stars, star clusters, gas, dust, and nebulae orbiting a common center of mass
a. galaxy
46. Earth orbits the Sun _____.
a. once a year
17. A(n) _____ is a cluster of galaxy clusters.
a. supercluster
41. In the context of astronomy _____ is the area visible in an image.
a. the field of view
Recombination
about 400,00 years of the big bang, neutral atoms formed and the gas of the universe became transparent to radiation
An atom can get the energy that moves an electron to a higher energy level by: transferring the electron to the ground state. preventing collisions with other atoms. absorbing a photon of electromagnetic radiation. moving the electron to a tightly bound level.
absorbing a photon of electromagnetic radiation.
In the context of the evidence on evolution of stars, you can estimate the _____ of a star cluster by observing the distribution of the points that represent its stars in the Hertzsprung-Russell (H-R) diagram.
age
The key point to remember when considering the Hertzsprung-Russell (H-R) diagram of a star cluster in determining the evolution of stars is that all of the stars in the star cluster have the same:
age but differ in mass.
acceleration and gravity
all falling objects fall at same rate (without friction, air resistance) -new constant that doesn't change near earth g = 10 m/s^2 = acceleration of gravity gm = weight = affects weight not mass
29. _____ is the nearest star to the Sun.
b. Proxima Centauri
A total solar eclipse occurred in Wolf Point, Montana on Feb. 26, 1979. When would this eclipse again be visible in Montana? a. within 3 days of August 26, 1979 b. within 3 days of March 29, 2033 c. within 3 days of March 9. 1997 d. within 3 days of March 13, 1979 e. within 3 days of Jan. 1, 2000
b
An eclipse season is the period of time during which the a. moon crosses a node in its orbit. b. sun crosses a node in the moon's orbit. c. line of nodes crosses the moon's orbit. d. moon is new or full. e. moon is visible during the day.
b
During a total lunar eclipse, which of the following are true? I. The photosphere of the sun is obscured. II. The moon is in Earth's umbra. III. The moon is new. IV. The moon is full. a. I, III b. II, IV c. I, II, III d. II, III e. I, II, III, IV
b
Total lunar eclipses always occur a. during the time of new moon. b. during the time of full moon. c. on either the vernal or autumnal equinox. d. on either the summer or winter solstice. e. when the moon is near one of the solstice points.
b
24. 2.36 × 108 is equal to _____.
b. 236,000,000
26. Proxima Centauri is _____ away from Earth.
b. 4.2 light-years
50. Light from Proxima Centauri takes _____ to reach Earth.
b. 4.2 years
36. When written in scientific notation 42,300,000,000 is equal to _____.
b. 4.23 × 1010
44. Our Sun and its planets were formed about _____.
b. 4.6 billion years ago
52. Light from the Sun reaches Earth in about _____.
b. 8 minutes
34. Identify a true statement about planets.
b. They shine by reflecting sunlight.
In the context of black holes, if an object collapses to zero radius, its density and gravity _____.
become infinite
The bright O and B tracers make the spiral arms of galaxies, including ours, appear to be ___.
blue
54. Which of the following is true of the Sun?
c. It is about 100 times larger in diameter than Earth.
38. Which of the following is true of Venus?
c. It is about the same size as Earth.
11. Identify a true statement about Venus.
c. It is more than 60 million miles away from the Sun.
19. The__________is the spiral galaxy that contains the Sun.
c. Milky Way Galaxy
28. Our Galaxy is called the _____.
c. Milky Way Galaxy
15. Which of the following objects is a part of the Solar System?
c. Neptune
Among the modes of energy transfer in stars, ___ is the least efficient of all.
conduction
35. Which of the following is an example of a star?
c. The Sun
According to the ___, the Moon formed elsewhere in the solar nebula and was later taken by Earth.
capture hypothesis
Comet nuclei contain ___.
carbon monoxide
Although this sphere does not actually exist, the ________ sphere is useful because it helps scientists locate the stars and planets.
celestial
The _____ is an imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun, and Moon seem to be attached.
celestial sphere
The spherical cloud of stars that lies at the center of spiral galaxies.
central bulge
A _____ is an electronic device consisting of a large array of light-sensitive elements used to record very faint images. photometer photographic plate charge-coupled device spectrograph
charge-coupled device Correct. A charge-coupled device (CCD) is an electronic device consisting of a large array of light-sensitive elements used to record very faint images. A CCD is a specialized computer chip that can contain more than a million microscopic light detectors arranged in an array about the size of a postage stamp.
___ are small icy bodies that orbit the Sun and produce tails of gas and dust when they approach the Sun.
comets
31. One light-year (ly) is roughly _____.
d. 1013 km
The Perseid meteor shower is named after a(n) ___.
constellation
All around the world, ancient cultures celebrated heros, gods, and mythical beasts by naming groups pf stars called
constellations
The different groups of stars in the night sky are called ________.
constellations
The expansion of a star to giant or supergiant size _____, and so the stars move toward the upper right in the Hertzsprung-Russell (H-R) diagram.
cools the stars outer layers
A ___ is a telescope designed to capture images of faint objects such as the corona of the Sun that are near relatively bright objects.
coronagraph
A waxing crescent moon is visible a. near the eastern horizon just before sunrise. b. near the eastern horizon just after sunset. c. near the western horizon just before sunrise. d. near the western horizon just after sunset. e. from sunset until sunrise.
d
The _____________ is 18 years and 111/3 days long. a. sidereal period b synodic period c. eclipse season d. saros cycle e. eclipse year
d
The phases of the moon are caused by its __________ and _______________. a. spherical shape; orbital motion around the sun b. cubical shape; orbital motion around the sun c. cubical shape; orbital motion around Earth d. spherical shape; orbital motion around Earth e. spherical shape; orbital motion around the sun
d
The saros cycle a. was used in ancient times to predict eclipses. b. is 18 years, 111/3 days long. c. comes from a Greek word that means repetition. d. all of the above e. none of the above
d
Which of the following is not visible during totality of a total solar eclipse? a. the corona of the sun b. the chromosphere of the sun c. prominences d. the photosphere of the sun e. all of the above
d
33. Identify a true statement about the Sun.
d. It generates its own energy.
45. Which of the following is true of a light-year(ly)?
d. It is a larger unit of distance than the astronomical unit.
43. Brian is working on a project that involves astronomical calculations. The numbers involved in the calculations are very large, and the calculations require him to write too many zeros. Which of the following methods should Brian use to express the numbers without writing a great many zeros?
d. Scientific notation
13. __________are long spiral pattern of bright stars clusters, gas, and dust.
d. Spiral arms
25. Which of the following is true of planets?
d. They are nonluminous bodies.
12. The Milky Way:
d. is larger than most other galaxies.
40. Joseph writes the numbers 100,000,000,000, 3,240,000,000, and 48,000,000,000 as 1011, 3.24 × 109, and 4.8 × 1010. In this case, Joseph has used _____ to express the numbers in a simple way.
d. scientific notation
The energy believed to fill empty spaces and drive the acceleration of the expanding Universe.
dark energy
___ is the energy believed to fill empty spaces and drive the acceleration of the expanding universe.
dark energy
Nonluminous matter that is detected only by its gravitational influence.
dark matter
___ is the nonluminous matter that is detected only by its gravitational influence.
dark matter
Extremely high-density matter in which, due to quantum mechanical effects, pressure does not depend on temperature is termed__________
degenerate matter
What is extremely high-density matter in which pressure does not depend on temperature called?
degenerate matter
The pressure in a gas:
depends on the temperature of the gas
A(n) _____ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant. paradigm equant ellipse deferent
ellipse Correct. An ellipse is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant.
___ are the most round and contain no visible gas or dust and lack hot, bright stars.
elliptical galaxies
Claudius Ptolemy attempted to explain the motion of the planets through mathematical analysis by devising a small circle known as the ________.
epicycle
Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the _____ that slid around a larger circle called the deferent. hemicycle heterocycle epicycle pericycle
epicycle Correct. Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the epicycle that slid around a larger circle called the deferent.
newtonian gravitation/universal mutual gravitation
equal forces are mutual, all objects with mass attract all other masses in universe so it's universal
If you move an electron from a lower energy level to a higher energy level, you can call the atom a(n) ___.
excited atom
A supernova is up to 50,000 times less luminous than a normal nova and lasts for a much shorter period.
false
An absorption spectrum is also called a bright-line spectrum.
false
An expanding shell of gas ejected from a medium-mass star during the latter stages of its evolution is known as a black hole.
false
Earth's magnetosphere is 100 times larger than Jupiter's.
false
In a Hertzsprung-Russell (H-R) diagram, points near the top of the diagram represent very low luminosity stars and points near the bottom represent very luminous stars.
false
In the Copernican model, Venus moves around an epicycle centered on a line between Earth and the Sun.
false
In the context of the transitions in a hydrogen atom, the Lyman series lies in the infrared region.
false
Outflow channels on the Martian surface have remain unchanged since their formation.
false
Sunspots are hot spots on the Sun's surface caused by weak magnetic fields.
false
T Tauri stars are post-main-sequence stars.
false
The complete magnetic cycle is 11 years long, whereas the sunspot cycle is 22 years long.
false
The eyepiece is the main mirror or lens of a telescope.
false
The nearest star to the Sun is Sirius.
false
The signs of the zodiac are important to astronomy as they influence the seasons on Earth.
false
Ultraviolet light has wavelengths longer than violet light.
false
Uranus is an example of a Terrestrial planet.
false
Valley networks are located in Mars's northern hemisphere.
false
An object in a stable orbit continuously misses Earth because of its vertical velocity. false true
false Correct. An object in a stable orbit continuously misses Earth because of its horizontal velocity.
Electromagnetic waves with wavelengths shorter than gamma rays are called infrared radiation. false true
false Correct. Electromagnetic waves with wavelengths shorter than UV light are called X-rays, and the shortest are gamma rays. Infrared radiation has wavelengths longer than the visible range.
Claudius Ptolemy discovered that the orbit of Mars is an ellipse. false true
false Correct. Johannes Kepler discovered that the orbit of Mars is an ellipse, not a circle. Thus, he abandoned the ancient belief in the circular motion of the planets.
An interferometer consists of maximum of two telescopes connected to each other. false true
false Correct. One way to improve resolving power is to connect two or more telescopes in an interferometer, which has a resolving power equal to that of a telescope as large as the maximum separation between the individual telescopes.
Gamma rays have less energy than infrared radiation. false true
false Correct. The amount of energy a photon carries depends on its wavelength. Shorter-wavelength photons carry more energy, and longer-wavelength photons carry less energy. Gamma rays have shorter wavelengths than infrared radiation.
The eyepiece is the main mirror or lens of a telescope. false true
false Correct. The main lens in a refracting telescope is called the primary lens, and the main mirror in a reflecting telescope is called the primary mirror. Both kinds of telescopes form a small, inverted image that is difficult to observe directly, so a lens called the eyepiece is used to magnify the image and make it convenient to view.
When RIGHT half of the moon is illuminated, it is known as the _______ quarter moon.
first
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from
first principles
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from ___.
first principles
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from _____. careful observations geometric models first principles personal experience
first principles Correct. Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from first principles. A first principle was something that seemed obviously true to everyone and supposedly needed no further examination.
According to the ___, the Moon broke from a rapidly spinning proto-Earth.
fission hypothesis
Spicules are:
flamelike jets of gas extending upward into the chromosphere and lasting 5 to 15 minutes
A _____ is a piece of glass with thousands of microscopic parallel lines scribed onto its surface to produce a spectrum. charge-coupled device spectrograph grating photometer
grating Correct. A grating is a piece of glass or plastic with thousands of microscopic parallel lines scribed onto its surface to produce a spectrum. Different wavelengths of light reflect from the grating at slightly different angles, so white light is spread into a spectrum and can be recorded, often by a charge-coupled device camera.
In the context of star masses, ___ is the key to determining mass.
gravity
What force pulls the clouds of gas and dust together?
gravity
The process by which an atmosphere traps heat and raises the temperature of a planetary surface is known as the ___.
greenhouse effect
The lowest energy level an electron can occupy is called the ___.
ground state
The lowest energy level an electron can occupy is called the _____. ground state Doppler shift redshift ionization level
ground state
constellation
groups of stars named after gods, heroes, and mythical beasts
perigee
highest velocity when it is closest to Earth (perigee). _____________ must be above Earth's atmosphere, or friction will rob the satellite of energy and it will quickly fall back to Earth. point in an orbit that is closest to the earth
The main reason for connecting two or more telescopes in an interferometer is to: increase diffraction fringes. improve resolving power. observe more objects in a shorter amount of time. enhance seeing.
improve resolving power. Correct. One way to improve resolving power is to connect two or more telescopes in an interferometer, which has a resolving power equal to that of a telescope as large as the maximum separation between the individual telescopes
A(n)__________is a rule that the strength of an effect (such as gravity) decreases in proportion as the distance squared increases. parallel square relation direct square relation proportionate square relation inverse square relation
inverse square relation
The process in which atoms lose or gain electrons is referred to as _____. collimation ionization a redshift the Doppler effect
ionization
Galaxy that is a chaotic mix of gas, dust, and stars.
irregular
What type of galaxy is the Large Magellanic Cloud?
irregular
Nanometer is a unit of _____.
length
Nanometer is a unit of _____. mass energy frequency length
length
Nanometer is a unit of _____. length frequency energy mass
length Correct. Nanometer is a unit of length or distance equaling one-billionth of a meter (10-9 m). It is commonly used to measure the wavelength of light
asterism
less formally defined groupings
A graph of brightness versus time commonly used in analyzing eclipsing binaries.
light curve
What unit of measurement is used to describe extraordinary large distances, such as the distance of other stars from our own?
lightyears
Kepler's second law
line from planet to sun sweeps over equal areas in equal intervals of time (moves faster closer to the sun)
A massless atomic particle that travels at or nearly the speed of light.
neutrino
1) If you looked back at Earth from the moon, what phase would Earth have when the moon was full? New? A first-quarter moon? A waxing crescent? Other phases?
new earth, full earth, third quarter earth, waning gibbous earth
The Moon grows from ___ to ___ during the first two weeks of the lunar cycle.
new moon, first quarter
Which of the following metals is a constituent of iron meteorites?
nickel
The points where the moon passes through the plane of Earth's orbit are called the _________ of the moon's orbit.
nodes
In the context of binary systems, a ___ is an explosion involving a white dwarf.
nova
__ is reactions that break the nuclei of atoms into fragments.
nuclear fission
___ is the part of the Universe that you can see from your location in space and time.
observable universe
A telescope performs best:
on a high mountaintop where the air is thin and steady.
On the autumnal equinox, the Sun is:
on the celestial equator and moving south with respect to the equator.
Kepler's first law
orbit of planets are ellipses, sun at one focus
Kepler's third law
orbital period (p) squared is proportional to semi major axis cubed =orbital period and semi-major axis are related =planets closer to sun have smaller orbits, move faster =mass does not matter = only distance =if distance is doubled, orbital period will more than double
Kepler's third law of planetary motion states that:
orbital period and semi-major axis are related.
A cluster containing a thousand or more galaxies, usually mostly ellipticals, scattered over a volume only a few Mpc in diameter is reffered to as a(n) ___.
rich galaxy cluster
Granulation is caused by:
rising and falling currents of gas in and just below the photosphere.
__ is the motion around an axis passing through the spinning body.
rotation
A method of determining a galaxy's mass by measuring the orbital velocity and orbital radius of stars in the galaxy.
rotation curve method
The time taken by the Moon to circle the sky once and return to the same position among the stars is known as the Moon's ___.
sidereal period
The time taken by the Moon to circle the sky once and return to the same position among the stars is known as the Moon's _____.
sidereal period
The Copernican model was a __________ model compared to the Ptolemaic model.
simplified
Ancient philosophers and astronomers accepted without question—as first principles—that: there are many galaxies in the Universe. heavenly objects must move in circular paths at varying speeds. the planets are made of rock and gas, much like Earth. the Earth is motionless at the center of the Universe.
the Earth is motionless at the center of the Universe. Correct. Ancient philosophers and astronomers accepted without question—as first principles—that heavenly objects must move on circular paths at constant speeds, and that the Earth is motionless at the center of the Universe.
More than 2000 years ago, Hipparchus compared the positions of some stars with their positions recorded nearly two centuries previously and realized that: the celestial poles and equator were slowly moving across the sky. the stars were moving closer to each other. the celestial poles and equator remained stationery. the stars were moving across the sky randomly.
the celestial poles and equator were slowly moving across the sky.
___ is the site of most of the star formation in the Milky Way Galaxy.
the disk component
Ancient Philosophers and astronomers accepted without question as first principles that
the earth is motionless at the center of the universe
In the context of the magnitude scale, the larger the magnitude number of a star
the fainter the star is
In the context of the magnitude scale, the larger the magnitude number of a star, _____.
the fainter the star is
Ancient astronomers believed that Earth did not move because they saw no parallax. true false
true Correct. Ancient astronomers believed that Earth did not move because they saw no parallax, the apparent motion of an object because of the motion of the observer.
To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant. true false
true Correct. To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant.
The geocentric theory was supported by _______ commonly made observations.
two
The ________ is the area where the sun is completely hidden behind Earth, creating a total shadow.
umbra
The region of a shadow that is totally shaded is known as _____
umbra
A white dwarf is:
unable to generate energy by nuclear fusion
The ___ of active galactic nuclei (AGN) is an attempt to explain the different types of AGN using a single model viewed from different directions.
unified model
__________is one of the ice giants of the Solar System.
uranus
A(n) __________ moon is visible in the southeastern sky just after sunset.
waxing gibbous
apparent visual magnitude
way of describing how stars look to the human eyes observing from earth
An object's ___ is the force that Earth's gravity exerts on the object.
weight
An object's _____ is the force that Earth's gravity exerts on the object
weight
An object's _____ is the force that Earth's gravity exerts on the object. density weight volume mass
weight
An object's _____ is the force that Earth's gravity exerts on the object. volume density mass weight
weight Correct. An object's weight is the force that Earth's gravity exerts on the object
According to astronomers, the Milky Way is ___.
wheel shaped
