astronomy 1 midterm

investigators gather information called _____ to test the predictions through observation and experimentation. the information is analyzed to find patterns in the _____.

data, data

the scientific method is a process for ______ the best possible explanation as to why something occurs.

discovering

pseudosciences such as astrology, typically make predictions ___________, and offer explanations that ___________ a coherent framework of ideas.

that cannot be tested, do not fit within

The blackbody curve of a star moving toward Earth would have its peak shifted .... - toward higher energies - to a lower intensity - toward longer wavelengths - to a higher intensity

toward higher energies

A partial lunar eclipse begins when the Moon first touches Earth's ______.

umbra

Electromagnetic waves are able to travel through a ___.

vacuum

When a thin crescent of the Moon is visible just before sunrise, the Moon is in its ... - waning phase - new phase - quarter phase - waxing phase

waning phase

Compared with ultraviolet radiation, infrared radiation has a greater ... - amplitude - frequency - wavelength - energy

wavelength

What's so special about c?

"C" represents the speed of light and its constant in a vacuum. It's special because it doesn't change.

Observational proof of the heliocentric model Astronomers have made many observations since the days of Galileo and Kepler to confirm that the Sun really is at the center of the solar system, and that the planets revolve around the Sun in elliptical orbits. Which observation(s) could you make today that Galileo and Kepler could not have made to confirm that the heliocentric model is correct? (Check all that apply.) - Doppler shifts in stellar spectra of nearby stars. - Orbital periods of Jupiter's moons. - Transit of an extrasolar planet. - Stellar parallax in nearby stars.

- Doppler shifts in stellar spectra of nearby stars. - transit of an extrasolar planet. - stellar parallax in nearby stars.

Anyone looking from the night side of Earth can, in principle, see a(n) ____.

total solar eclipse

Galileo's observational contributions Galileio Gaililei was the first scientist to perform experiments in order to test his ideas. He was also the first astronomer to systematically observe the skies with a telescope. Galileo made four key observations that challenged the widely accepted philosophical beliefs on which the geocentric model was based, thus providing support for the heliocentric model. From the following list of observations, which are the key observations made by Galileo that challenged widespread philosophical beliefs about the solar system. (Check all that apply.) - Neptune has orbiting moons. - Jupiter has orbiting moons - the Moon has a smooth, featureless surface - the Sun has sunspots and rotates on its axis - Venus is only seen in a crescent phase - Venus goes through a full set of phases - Uranus has a ring system - the Moon has mountains, valleys, and craters

- Jupiter has orbiting moons. - the Sun has sunspots and rotates on its axis. - the Moon has mountains, valleys, and craters - Venus goes through a full set of phases.

The geocentric model, in all of its complexity, survived scientific scrutiny for almost 1,400 years. However, in modern astronomy, scientists seek to explain the natural and physical world we live in as simply as possible. The complexity of Ptolemy's model was an indicator that his theory was inherently flawed. Why, then, was the geocentric model the leading theory for such a long time, even though the heliocentric model more simply explained the observed motions and brightness of the planets? (Check all that apply.) - Ancient astronomers did not observe stellar parallax, which would have provided evidence in favor of the heliocentric model. - The heliocentric model did not make noticeably better predictions than the geocentric model. - The geocentric model conformed to both the philosophical and religious doctrines of the time. - From Earth, all heavenly bodies appeared to circle around a stationary Earth. - The complexity of the geocentric model was appealing to most ancient astronomers.

- The geocentric model conformed to both the philosophical and religious doctrines of the time. - The heliocentric model did not make noticeably better predictions than the geocentric model. - From Earth, all heavenly bodies appeared to circle around a stationary Earth. - Ancient astronomers did not observe stellar parallax, which would have provided evidence in favor of the heliocentric model.

What are Newton's laws of motion and gravity?

-Newton's first law of motion is "Every body continues in a state of rest or in a state of uniform motion in a straight line, unless it is compelled to change that state by a force acting on it," which means that a moving object will move forever in a straight line unless an external force pushes or pulls its speed of direction of motion. -Newton's second law of motion is "When a force F acts on a body of mass m, it produces in it an acceleration a equal to the force divided by the mass. Thus, a=F/m, or F = ma. -Newton's third law of motion is "To every action, there is an equal and opposite reaction." -Newton's law of universal gravitation is that all objects in the universe attract each other by the force of gravity.

Electromagnetic waves travel at a speed of ___.

300,000 km/s

Suppose an electron in some atom absorbs energy and transitions from level 1 up to level 4. Which of the following is a true statement regarding the electron transitions back down to level 1? - it must transition from 4 to 3, then 3 to 2, the 2 to 1. all downward transitions are one step at a time. - it can go from 4 to 1 only. the downward transitions must match the upward one. - 4 to 2, followed by 2 to 1, is possible. downward transitions can be any number of levels.

4 to 2, followed by 2 to 1, is possible. downward transitions can be any number of levels.

What is a constellation? Why are constellations useful for mapping the sky?

A constellation is a human grouping of stars in the night sky into recognizable patterns. Constellations are useful for mapping the sky because it helped astronomers recognize the stars in the sky. For example, by seeing the patterns of the stars, the location of the stars made it easier for astronomers to spot them, and they provided a convenient means to specify different regions in the sky.

How are absorption and emission lines produced in a stellar spectrum? What information might absorption lines in the spectrum of a star reveal about a cloud of cool gas lying between us and the star?

Absorption lines are produced when a certain molecule or element gets hit with another light form as it absorbs the light. The absorption spectra shows black lines where no light goes through the element. The electron then jumps back as it must absorb the same frequency photon. Emission spectra is produced when colored lines are shown when an element produces a certain color as the electron jumps back down to their energy level. According to their specific frequency, they will emit their corresponding color photon.

In terms of its blackbody curve, describe what happens as red-hot glowing coal cools.

As red-hot glowing coal cools, its peak will move to the left that is longer wavelength or lower frequency according to Wien's Law. According to Stefan's law the area underneath will also decrease.

Why are gamma rays generally harmful to life-forms, but radio waves generally harmless?

Gamma rays are harmful to life-forms because they have enough energy to harm living tissues which can then break up important molecules like DNA. Radio waves are generally harmless because they have the ability to pass through tissues without interacting, which is then harmless.

An asteroid with an orbit lying entirely inside Earth's ... - has an orbital semi-major axis of less than 1 AU - has a longer orbital period than Earth's - must have a highly eccentric orbit. Consider again the diagrams from Parts D and E, which are repeated here. Again, imagine that you observed the asteroid as it traveled for one week, starting from each of the positions shown. This time, rank the positions (A-D) from left to right based on how fast the asteroid is moving at each position. - Rank from fastest to slowest. If you think that two (or more) of the diagrams should be ranked as equal, drag one on top of the other(s) to show this equality. - moves more slowly than Earth

Has an orbit semi-major axis of less than 1 AU.

Kepler's contributions Johannes Kepler used decades of Tycho Brahe's observational data to formulate an accurate description of planetary motion. Kepler spent almost 30 years of his life trying to develop a simple description of planetary motion based on a heliocentric model that fit Tycho's data. What conclusion did Kepler eventually come to that revolutionized the heliocentric model of the solar system? - Kepler determined that the planetary orbits are elliptical. - Kepler explained retrograde motion. - Kepler confirmed that the planetary orbits are circular. - Kepler confirmed that Venus orbits the Sun.

Kepler determined that the planetary orbits are elliptical.

Compared with slowly rotating stars, the fastest spinning stars have absorption lines that are ... - thin and distinct - broad and fuzzy - identical to the lines in the slowly rotating stars

broad and fuzzy

According to Kepler's second law, Pluto will be traveling fastest around the Sun when at ___.

Perihelion.

If radio waves cannot be reflected from the Sun, how can radar be used to find the distance from Earth to Sun?

Radar can be used to find the distance from Earth to the Sun by using Kepler's 3rd law, which is the cube of a planet's average distance from the Sun because it's proportional to the square of its orbital period.

Suppose a particular spectral line has a wavelength of 500 nm in the lab. If you look at the spectrum of star A, you see this line at 480 nm. Star B exhibits this line at 510 nm, and the line is measured to be at 530 nm in star C. Which of the following statements is true? - star A is moving the fastest of the three stars. star A is the only star moving away from us, star B and star C are both moving towards us (with star C moving towards us the fastest). - star C is moving away from us faster than star B, star A is moving towards us.

Star C is moving away from us faster than star B, star A is moving towards us.

The visible spectrum of sunlight reflected from Saturn's cold moon Titan would be expected to be ... - continuous - emission spectrum - absorption spectrum

absorption spectrum

can a theory ever be proven to be absolutely true? - a theory can never be proven to be absolutely true - a theory can be proven to be absolutely true

a theory can never be proven to be absolutely true

what is a scientific theory? - a theory is a framework of ideas and assumptions that represents our best possible explanation for something. - a theory is a process for the initial explanation for something. - a theory is a process for the best possible explanation for something. - a theory is a framework of ideas and assumptions that represents our initial explanation for something.

a theory is a framework of ideas and assumptions that represents our best possible explanation for something.

If you throw a rock into a pond, it creates a wave in the water. What is responsible for creating an electromagnetic wave? - a vibrating uncharged particle - a vibrating charged particle - a stationary uncharged particle - a stationary charged particle

a vibrating charged particle

Astronomers analyze starlight to determine a star's ... - temperature - motion - composition - all of the above

all of the above

A solar eclipse that occurs when the new moon is too far from Earth to completely cover the Sun can be either a partial solar eclipse or a(n) _____.

annular eclipse

According to Kepler's second law, Jupiter will be traveling most slowly around the Sun when at ___.

aphelion

Imagine that Venus is in its full phase today. If we could see it, at what time would the full Venus be highest in the sky? - at noon - just after the sunset - midnight - just before dawn

at noon

when would a new Venus be highest in the sky? - just after sunset - midnight - just before dawn - at noon

at noon

Compared with red light, blue wavelengths of visible light travel ... - faster - slower - at the same speed

at the same speed

Figure 2.21 in the textbook ("Gravity"), showing the motion of a ball near Earth's surface, depicts how gravity ... - causes the ball to accelerate upward - causes the ball to accelerate downward - increases with altitude - has no effect on the ball

causes the ball to accelerate downward.

The extent to which Mars' orbit differs from a perfect circle is called its ____.

eccentricity.

Earth orbits in the shape of a/an ___ around the Sun.

ellipse

Electromagnetic waves consist of co-oscillating electric and magnetic ____.

fields

If the Sun and its mass were suddenly to disappear, Earth would ... - fly off into space - suddenly change its orbital speed - stop spinning - continue in its current orbit

fly off into space

Earth is located at one ___ of the Moon's orbit.

focus

in Ptolemy's Earth-centered model for the solar system, Venus's phase is never full as viewed from Earth because it always lies between Earth and the Sun. in reality, as Galileo first recognized, Venus is ... - never full because Earth's shadow falls on Venus at the time when it would otherwise be full. - never be full because the sunlit side of Venus never faces directly toward Earth. - full whenever it lies directly between Earth and the Sun - full whenever it is on the opposite side of the Sun from Earth, although we cannot see the full Venus because it is close to the Sun in the sky

full whenever it is on the opposite side of the Sun from the Earth, although we cannot see the full Venus because it is close to the Sun in the sky.

Suppose you are in an elevator. As the elevator starts upward, its speed will increase. During this time when the elevator is moving upward with increasing speed, your weight will be ... - greater than your normal weight at rest - equal to your normal weight at rest - less than your normal weight at rest

greater than your normal weight at rest.

An atom that has been ionized ... - has more protons that electrons - is radioactive - is electrically neutral - has equal numbers of protons

has more protons and electrons

the process begins when observations lead to the formulation of a _____, a preliminary explanation that makes testable.

hypothesis

if they do not agree, the _____ must be ______.

hypothesis, discarded or modified

if the patterns agree with the predictions, the _____ is considered a viable ______.

hypothesis, theory

Stefan's law says that if the Sun's temperature were to double, its energy emission would ... - become half its present value - double - increase four times - increase 16 times

increase 16 times

Suppose you are in an elevator that is moving upward. As the elevator nears the floor at which you will get off, its speed slows down. During this time when the elevator is moving upward with decreasing speed, your weight will be ... - greater than your normal weight at rest - equal to your normal weight at rest - less than your normal weight at rest

less than your normal weight at rest

Compared with an electron transition from the first excited state to the ground state; a transition from the third excited state to the second excited state emits of photon of ... - greater energy - lower energy - identical energy

lower energy

science therefore relies on _____________ to search for answers.

measurable quantities and testable predictions

If the Moon's orbit were a little larger, solar eclipses would be ..... - more likely to be total - more likely to be annular - more frequent - unchanged in appearance

more likely to be annular

If Earth's orbit around the Sun were twice as large as it is now, the orbit would take ... - less than twice as long - two times longer - more than two times longer to traverse

more than two times longer to traverse

Figure 2.26(b) in the textbook ("Orbits") shows the orbit of two stars of unequal masses. If one star has twice the mass of the other, then the more massive star ... - has twice the eccentricity of the less massive star - moves more slowly than the less massive star - has half the gravity of the less massive star - moves more rapidly than the less massive star

moves more slowly than the less massive star

when would you expect to see Venus high in the sky at midnight? - in its waxing gibbous phase - in its waning crescent phase - in its waxing crescent phase - in its full phase - never

never

Figure 4.3 in the textbook ("Elemental Emission") shows the emission spectrum of neon gas. If the temperature of the gas was increased, we would observe ... - some faint absorption features - even more red lines - fewer red lines and more blue lines - no significant change

no significant change

A point at which the Moon crosses Earth's orbital plane is called a(n) _____.

node

if a claim is ______, it cannot be considered scientific.

not testable

As shown in Figure 2.12 in the textbook ("Venus Phases"), Galileo's observations of Venus demonstrated that Venus must be ... - orbiting Earth - orbiting the Sun - about the same diameter as Earth - similar to the Moon

orbiting the Sun.

Energy and information flows ___ to the direction of wave motion.

parallel

During some lunar eclipses, the moon's appearance changes only slightly because it passes only through the part of Earth's shadow called the ___

penumbra

The wave amplitudes are directed ___ to the direction of a wave motion.

perpendicular

An electron that collides with an atom will ... - become magnetized - produce an electromagnetic wave - cease to have an electric field - change its electric charge

produce an electromagnetic field

A star much cooler than the Sun would appear ... - red - blue - smaller - larger

red

planets near opposition ... - do not rise or set - rise in the east - have larger defendants - rise in the west

rise in the east

The mathematical form of Kepler's third law measures the period in years and the ___ in astronomical units (AU).

semi-major axis

Compared with a spectrum from a ground-based observation, the spectrum of a star observed from above Earth's atmosphere would show ... - no absorption lines - fewer emission lines - slightly fewer absorption lines - many more absorption line s

slightly fewer absorption lines

Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton's second law of motion ___. - the Moon has a larger acceleration than Earth, because it has smaller mass - Earth has a larger acceleration than the Moon, because it has a larger mass - the Moon and Earth both have equal accelerations, because the forces are equal.

the Moon has a larger acceleration than the Moon, because it has a larger mass.

Your weight will be greater than normal when the elevator is moving upward with increasing speed. For what other motion would your weight also be greater than your normal weight? - The elevator moves upward with constant velocity. - The elevator moves downward with constant velocity. - The elevator moves upward while slowing in speed. - The elevator moves downward while slowing in speed. - The elevator moves downward while increasing in speed.

the elevator moves downward while slowing in speed.

If you are standing on a scale in an elevator, what exactly does the scale measure? - your mass - the force you exert on the scale - the gravitational force exerted on you by Earth

the force you exert on the scale

the benefit of our current knowledge lets us see flaws in the Ptolemaic model of the universe. what is its basic flaw?

the most basic flaw in the Ptolemaic model of the universe is that it is geocentric and it does not explain its retrograde in motion.

According to Wien's law, the hottest stars also have ... - the largest diameters - the longest peak wavelength - maximum emission in the infrared region of the spectrum - the shortest peak wavelength

the shortest peak wavelength

What does an astronomer mean by "the universe"?

the totality of all space, time, matter, and energy

A calculation of how long it takes a planet to orbit the Sun would be most closely related to Kepler's ... - third law of planetary distances - second law of orbital speeds - first law of orbital shapes - first law of inertia

third law of planetary distances

A(n) ____ can occur only when the Moon is new and has an angular size larger than the Sun in the sky.

total lunar eclipse

Why do we see different stars at different times of the year?

we see different stars at different times of the year because of the change of the Earth moving. for example, after 6 months Earth will reach the opposite side of its orbit and we will see an entirely different set of stars.

In Ptolemy's Earth-centered model for the solar system, Venus always stays close to the Sun in the sky and, because it always stays between Earth and the Sun, its phases range only between new and crescent. The following statements are all true and were all observed by Galileo. Which one provides evidence that Venus orbits the Sun and not the Earth? - we sometimes see gibbous (nearly but not quite full) Venus - we never see Venus at midnight - we need a telescope to observe the phases of Venus - we sometimes see a crescent Venus

we sometimes see gibbous (nearly but not quite full) Venus.