Astronomy Final
Copernicus had the Earth moving around the Sun and not at the center of the universe.
The Copernican System.
In addition to measuring the positions of all the planets all the time, Tycho Brahe measured them to an accuracy of -1/60 degree of arc -five degrees of arc -1/3600 degree of arc -1/10 degree of arc -one degree of arc
-1/60 degree of arc
At 8 p.m., you see that the pointer stars of the Big dipper and the star Polaris are arranged in a vertical line. At what time would you see them arranged in a horizontal line? -7:56 p.m. the next day. -1:59 a.m. the next day. -9:59 p.m. that same day. -10:59 p.m. that same day. -It will never happen.
-1:59 a.m. the next day
The brightest star in the constellation Centaurus might be named -Alpha Centauri. -Delta Cephei. -Alpha Cephei. -Delta Centauri.
-Alpha Centauri.
Most of the ancient Greek astronomers believed that the Earth was fixed at the center of the universe. There was one, however, who thought that the Sun was fixed and a rotating Earth moved around the Sun. That was -Eristarchus of Syene -Plato -Aristotle -Aristarchus of Samos
-Aristarchus of Samos
You read in an Astronomy book that the temperature at the center of the Sun is 30,000,000 degrees Kelvin. How do you suppose this number was determined? -By sending a well-shielded space probe into the center of the Sun. -By using a model of the Sun that is elegant but not tested against actual measurements. -By using a special telescope that can see inside the Sun. -By using a model of the Sun that correctly accounts for everything that has been measured so far.
-By using a model of the Sun that correctly accounts for everything that has been measured so far.
Which of the following statements is falsifiable? -There is intelligent life on some other planet somewhere in the universe. -The Minoans were the best civilization on Crete. -There is beauty in a sunset. -There are fish in Lake Nyak. -Dinosaurs are extinct.
-Dinosaurs are extinct.
The largest dwarf planet in the Kuiper Belt is -Pluto. -Varuna. -Quaoar. -Eris.
-Eris.
Who discovered Newton's First Law of Motion? -Galileo. -Kepler. -Newton. -Aristotle.
-Galileo.
The Ptolemaic System continued to be accepted long after such people as Aristarchus and Copernicus had proposed alternatives. All of the following reasons why it lasted so long are at least partly true. Which reason is the one that would be stressed by the philosophy of science that we have been discussing? -It was easier to understand and people do not like to learn new things. -It correctly predicted what was observed and thus did not need to be replaced. -Church authorities supported it and did not want it replaced.
-It correctly predicted what was observed and thus did not need to be replaced.
The statement that the orbit of each planet is an ellipse with the Sun at one focus is due to -Copernicus. -Galileo. -Kepler. -Newton.
-Kepler.
Mars is farther from the Sun than Earth. Which of the following statements is true? -Mars takes longer to go around the Sun that the Earth because it has farther to go, but actually moves at the same speed as the Earth. -Mars takes longer to go around the Sun than Earth and moves more slowly than the Earth does. -Mars takes less time to go around the Sun than the Earth and moves much faster. -Mars takes longer to go around the Sun than the Earth because it has farther to go, but actually moves faster than the Earth.
-Mars takes longer to go around the Sun than Earth and moves more slowly than the Earth does.
We can use the pointer stars in the Big Dipper to locate a point in the sky near the -South Celestial Pole. -North Celestial Pole. -East Celestial Pole. -Star Sirius. -Celestial Equator.
-North Celestial Pole
You are looking down on the Earth from a spacecraft hovering far above. After watching for a while, you notice that from your perspective, it is rotating counterclockwise. The part of the Earth that is directly below you must be the Earth's -North Pole. -South Pole. -Prime Meridian. -Equator.
-North Pole
The star Sirius can be located by using the pointer stars in -The Little Dipper. -The Big Dipper. -Orion. -Cassiopeia. -Leo.
-Orion
Fred reports that a special arrangement of wire coils can draw electrical power from the air. He really built the device and was very surprised when it really did produce electrical power. The most likely outcome of his report is that: -Nobody bothers to check his observation and nobody believes him either. -Other people build the proposed device. It generates power just as he said and he becomes famous as the discoverer of a source of endless electrical power. -Nobody bothers to check his observation and he becomes famous as the discoverer of a source of endless electrical power. -Other people build the proposed device. They do not see any electrical power, and attack his report as a mistake or a fraud.
-Other people build the proposed device. It generates power just as he said and he becomes famous as the discoverer of a source of endless electrical power.
Sarah reports that she saw a green star close to the star Betelgeuse. Actually she did not even look there. The most likely outcome of her fraud is that: -Other people look near Betelgeuse. They see the star and confirm her report. She becomes famous as the discoverer of the first green star. -Nobody bothers to check her observation and she becomes famous as the discoverer of the first green star. -Nobody bothers to check her observation and nobody believes her either. -Other people look near Betelgeuse. They do not see the green star, and attack her report as a mistake or a fraud.
-Other people look near Betelgeuse. They do not see the green star, and attack her report as a mistake or a fraud.
Which of these was the Solar System model that assumed the Earth is fixed and the Sun, Moon, and planets all move on epicycles that, in turn move on circular orbits around the Earth? -Copernican model. -Tychonic model. -Keplerian model. -Ptolemaic model.
-Ptolemaic model.
The Greek philosopher who guessed that the Earth is a sphere because that is the most elegant and simple shape was -Aristarchus. -Pythagoras. -Plato. -Eratosthenes. -Aristotle.
-Pythagoras
You would expect to see a waning crescent Moon -Setting in the West right after the Sun. -Rising in the East just before the Sun. -Setting in the East right after the Sun. -Rising in the West just before the Sun.
-Rising in the East just before the Sun.
The first telescope was (possibly) built by -Someone in the Netherlands. -Tycho Brahe. -Newton. -Galileo.
-Someone in the Netherlands.
Sven, a well-known Loch Ness Monster fanatic, often reports seeing the monster but is usually ignored. One evening, while watching the monster swim around in the light of the setting sun, Sven notices that the tide is out and there is a quarter Moon in the sky. He tells this story to a newspaper reporter who humors him and shows up to look for the monster the next time there is a low tide at sunset with a quarter moon. Sure enough, the monster appears. A local university then sends a biologist with a truckload of cameras at the next sunset-low-tide-quarter-moon and the monster again shows up on cue. Sven's observations of the monster are now accepted by the scientific community because -Scientists really like monster stories. -Sven told a good story with lots of details. -Sven's observations were reproduced by others. -Sven saw the monster many times.
-Sven's observations were reproduced by others.
Which of Kepler's Laws governs how a particular planet speeds up and slows down? -The Equal Area Law. -The Period-Radius Relation. -The Law of Averages. -The Law of Inertia.
-The Equal Area Law
The Ptolemaic model of the Solar System accounted for the daily rising and setting of the Sun by assuming that -The Sun drops below the surface of the Earth when it sets and travels underground to get back to where it rises each day. -The Earth rotates on its axis once a day. -The Earth moves around the Sun once a day. -The Sun moves around the Earth once a day.
-The Sun moves around the Earth once a day.
An early measurement of noon Sun angles at the summer solstice at Alexandria and Syene needed one additional piece of information in order to determine the size of the Earth. -The solar time difference between Alexandria and Syene. -The longitudes of Alexandria and Syene. -The distance between Alexandria and Syene. -The latitudes of Alexandria and Syene.
-The distance between Alexandria and Syene.
The motion of the Moon around the Earth causes -Meteor Showers. -Daily motions in the Heavens. -The phases of the Moon. -Dandruff.
-The phases of the Moon.
You see the Moon almost directly in the south at 3 am. What phase is it? -Waxing gibbous. -Waning quarter. -Waning gibbous. -Full.
-Waning gibbous.
One property of a model such as the shape of the Earth is the number of adjustable parameters it has --- the number of numbers that are needed to determine the model. If this number is very large, that is regarded as -a good thing since it lets the model fit many possible measurements. -a bad thing since it lets the model fit many possible measurements. -of no importance so long as the model works.
-a bad thing since it lets the model fit many possible measurements.
An area of the sky that is marked by a recognizable pattern of stars is called -a celestial sector. -a stellar neighborhood. -a constellation. -an asterism.
-a constellation
It is expected that a normal Jovian planet, with no accident encounters that could add or subtract moons, should have -no moon. -two moons. -just one moon. -a family of moons, all orbiting in the plane of the planets equator.
-a family of moons, all orbiting in the plane of the planets equator.
The ancient Greeks concluded that the Sun is larger than the Earth because -total lunar eclipses never happen. -a total lunar eclipse happens only over a very small part of the Earth. -a total solar eclipse happens only over a very small part of the Earth. -a total solar eclipse happens everywhere on Earth at once.
-a total solar eclipse happens only over a very small part of the Earth.
In addition to being accurate, Tycho Brahe's observations focused on measuring the positions of the planets -when they were in retrograde motion. -near the horizon. -during the solstices. -all the time. -during conjunctions.
-all the time.
A reporter at the newspaper says that she saw a full moon last night. This statement is most likely -an unsupported opinion. -an actual observation of the natural world. -the result of calculation. -a proven mathematical theorem.
-an actual observation of the natural world.
The ancient Greeks were able to calculate the distance from the Earth to the Moon by using a geometrical model of -an eclipse of the Sun. -the full Moon. -an eclipse of the Moon. -the quarter phases of the Moon.
-an eclipse of the Moon.
Kepler's First Law of Planetary Motion is that the orbit of each planet is -an ellipse with the Sun at the center. -an ellipse with the Sun at one focus. -a circle with the Sun at the center. -a circle with the Sun offset from the center.
-an ellipse with the Sun at one focus.
Kepler's Laws -are explained by a force that attracts each planet to the Sun. -are explained by the action of magnetic fields on each planet. -have never been explained. -are explained by a force that repels each planet from the Sun.
-are explained by a force that attracts each planet to the Sun.
Galileo's approach to understanding moving objects was to -rely on pure logic and debate to arrive at the truth. -make up imaginary situations that he could understand. -build things that he could measure. -observe everyday objects such as spears and horses.
-build things that he could measure.
If you are looking down over the south pole of the Earth, you will see the Earth rotate -counterclockwise. -clockwise. -upward. -downward.
-clockwise
For Copernicus, a critical inconsistency in the final version of the Ptolemaic System was that it -had the Earth moving around the Sun. -had the Sun moving around the Earth -did not really have anything fixed in place at the center of the universe. -had the Earth fixed in place at the center of the universe.
-did not really have anything fixed in place at the center of the universe.
Copernicus said that the retrograde motion of the planets was caused by the -earth turning on its axis. -earth and the planets orbiting the Sun. -planets turning on their axes. -planets speeding up and slowing down. -planets moving on epicycles.
-earth and the planets orbiting the Sun.
Copernicus said that the daily motions in the heavens were caused by the -planets moving on epicycles. -earth turning on its axis. -planets turning on their axes. -earth and the planets orbiting the Sun.
-earth turning on its axis.
One objection to a solar system model that has the Earth moving around the Sun is that we would then see nearby stars seem to shift back and forth relative to more distant stars. The correct answer to that objection is that -all of the stars are attached to the same Celestial Sphere, so none are more distant that others. -gravity bends starlight in just the right way to undo the shift. -each star is moving in a circle exactly in step with the Earth's motion around the Sun. -even the closest stars are so far away that the shift is very small.
-even the closest stars are so far away that the shift is very small
Ancient astronomers were puzzled by the planets because they -look like stars. -rotate on their axes. -rise and set. -execute retrograde loops.
-execute retrograde loops
Kepler was an early advocate of the Copernican Theory. When he applied it to Tycho's observations, it -failed and was completely discarded. -failed but led to a better theory. -was as accurate as the observations. -worked perfectly.
-failed but led to a better theory.
Freely falling objects with different masses fall with the same acceleration because -gravity acts with the same force on both objects. -gravity exerts more force on the more massive object. -gravity acts with less force on the more massive object. -there is no air resistance. -they have the same inertia.
-gravity exerts more force on the more massive object.
Galileo observed that, so long as air resistance can be neglected, heavy objects fall in the same way as lighter objects. Newton explained this observation by noting that - heavier objects have more inertia but gravity acts on them with less force. -heavier objects have more inertia and gravity acts on them with more force. -heavy objects have the same inertia as lighter objects. -gravity acts with the same force on lighter objects as it does on heavier objects. -gravity acts with more force on lighter objects than it does on heavier objects.
-heavier objects have more inertia and gravity acts on them with more force.
For a planet that is following Kepler's Laws, the magnitude of the planet's acceleration is -inversely proportional to the square of the planet's distance from the Sun. -proportional to the square of the planet's distance from the Sun. -a constant. -inversely proportional to the the planet's distance from the Sun.
-inversely proportional to the square of the planet's distance from the Sun.
The Moon's orbit -is in the plane of the Earth's equator. -is in the plane of the ecliptic. -is perpendicular to the plane of the Earth's equator. -is somewhat tilted relative to the plane of the Earth's equator.
-is somewhat tilted relative to the plane of the Earth's equator.
The astronomers of Copernicus's time rejected his model of the Solar System mostly because -they failed to understand it. -it did not account for observations any better than the Ptolemaic System. -the Ptolemaic System was supported by the Church.
-it did not account for observations any better than the Ptolemaic System.
One reason that the Copernican System failed to fit Tycho's observations was that -it used elliptical orbits instead of circles. -it placed the Earth at the center of the universe. -it placed the Sun at the center of the system. -it used circular orbits instead of ellipses.
-it used circular orbits instead of ellipses.
The planet Neptune was located because -its gravity disturbed the orbit of Uranus. -its orbit was not elliptical. -it caused Mars to deviate from Kepler's Laws. -it lost a satellite which became Pluto.
-its gravity disturbed the orbit of Uranus.
Aristarchus measured the angle between the Sun and the Moon when exactly half of the Moon was illuminated. He found this angle to be -less than 90 degrees by an amount too small for him to measure. -greater than 90 degrees -less than 90 degrees by an amount that was easy for him to measure. -exactly 90 degrees
-less than 90 degrees by an amount too small for him to measure.
Compared to a sidereal month, the time from one full Moon to the next is -exactly the same. -longer by 2.5 days. -shorter by 2.5 days. -longer by four minutes.
-longer by 2.5 days.
Tycho Brahe's main contribution to the understanding of planetary motion was to -propose a new theory. -disprove Ptolemy's theory. -make extensive observations. -explain the observations
-make extensive observations.
In one day, the position of the Sun on the Celestial Sphere -moves eastward along the ecliptic by 1°. -moves westward along the ecliptic by 1°. -does not change at all. -moves westward along the ecliptic by 15°. -moves eastward along the ecliptic by 15°.
-moves eastward along the ecliptic by 1°.
At midsummer in Murmansk (which is the largest city north of the Arctic Circle), the Sun stays above the horizon for several days. This observation would conflict with the predictions of a model of the Sun's motion that has the Sun -remaining still while the Earth goes around the Sun. -moving over and under a flat Earth. -moving around the Earth.
-moving over and under a flat Earth.
As seen from North America, the constellation Ursa Major -never sets -sets in the south -sets in the east -sets in the west -sets in the north
-never sets
When an arrow is fired from a bow, the arrow keeps moving after it leaves the bow because -the displaced air pushes it from behind. -the force of its inertia pushes it. -no force stops it. -the force of the bow keeps acting on it.
-no force stops it.
The Greek theory of Gravity as a force pulling everything toward the center of the universe implied that the Earth should be fixed at the center of the universe. Which of the following models of the Solar System was in accord with that theory? -the model of Aristarchus that the Earth goes around the Sun. -the final version of the Ptolemaic System. -the Copernican System. -none of these models.
-none of these models.
Galileo's observation that Venus goes through a full cycle of phases just like the Moon was significant mainly because that is -what the Copernican Theory predicted. -not what the Ptolemaic Theory predicted. -what the Tycho Brahe Model predicted -not what the Copernican Theory predicted.
-not what the Ptolemaic Theory predicted.
Retrograde Motion refers to -planets actually rotating backwards on their axes relative to their usual direction of rotation -planets actually moving backwards relative to the distant stars in relation to their usual motion -planets appearing to rotate backwards on their axes relative their usual direction of rotation -planets appearing to move backwards relative to the distant stars in relation to their usual motion
-planets appearing to move backwards relative to the distant stars in relation to their usual motion
The ancient Greeks insisted that a worthwhile model of a situation had to -predict what really happens. -make a good story. -be consistent with their religious traditions.
-predict what really happens.
The thing that is useful about a scientific model of a physical system is that it -reveals the true nature of the real system. -provides the opportunity to make an artistic statement. -can be tested without observing the real system. -predicts the results of observations on real systems.
-predicts the results of observations on real systems.
The idea that science only deals with statements that are falsifiable, subject to possible disproof by observation, suggests that -science only deals with guesses. -science produces revisable facts. -science is always right. -science is always wrong.
-science produces revisable facts.
As seen from North America, the constellation Orion -sets in the west and southwest -sets in the east and southeast -never sets -sets in the northeast -sets in the northwest
-sets in the west and southwest
The time that it takes for the Earth to rotate once relative to the distant stars is called a -stellar standard day -solar day -galilean day -sidereal day
-sidereal day
At midsummer in Murmansk (which is the largest city north of the Arctic Circle), you would expect the Sun to -rise and set everyday. -stay below the horizon all day, everyday. -stay above the horizon all day, everyday. -rise and set twice a day.
-stay above the horizon all day, everyday.
The idea of scientific fact presents difficulties for the falsificationist philosophy that we have been discussing because that philosophy insists that every scientific statement is -just a guess. -infallible. -subject to change.
-subject to change.
Many primitive cultures have a model of the Sun's motion in which the Sun passes underneath a flat earth. This model predicts -nothing at all about how the Sun will appear. -that people in the far North or South might not see the Sun for many days. -that everyone on Earth sees the Sun rise and set each day.
-that everyone on Earth sees the Sun rise and set each day.
The stars, as seen from the Earth, appear to be attached to -the Celestial Sphere, a sphere that surrounds the Earth. -the top of the Earth's atmosphere. -the Heliopause, an off-center surface surrounding the Sun. -the Celestial Net, a mesh of wires surrounding the Earth.
-the Celestial Sphere, a sphere that surrounds the Earth.
In Newton's theory -the Earth and sun move around a common point which, in turn, goes around the Moon. -the Earth and Moon move around a common point which, in turn, goes around the Sun. -the Moon moves around the Earth which, in turn goes around the Sun. -the Earth moves around the Moon which, in turn, goes around the Sun.
-the Earth and Moon move around a common point which, in turn, goes around the Sun.
One observation that Aristotle used to justify a spherical model of the Earth was that -total eclipses of the Sun can be seen everywhere on Earth. -total eclipses of the Moon can be seen everywhere on Earth. -the Earth casts a curved shadow on the Moon during a lunar eclipse. -total eclipses of the Sun can be seen only along narrowly defined paths on the Earth's surface.
-the Earth casts a curved shadow on the Moon during a lunar eclipse.
The observation that there are constellations that can be seen from Egypt but not from Greece convinced the ancient Greeks that -stars hang close to the Earth. -the Earth is round. -the Earth is flat.
-the Earth is round
The ancient Greeks were able to estimate the distance from the Earth to the Sun by using -the curvature of the Earth's shadow on the Moon. -how long a lunar eclipse lasts. -how long a total solar eclipse lasts. -the angle between the Sun and a quarter Moon.
-the angle between the Sun and a quarter Moon.
For an object that is moving along a straight path, the acceleration is -the change in the object's speed divided by the time it takes. -the time the object is moving divided by the change in its speed during that time. -zero. -the distance the object travels divided by the time it takes.
-the change in the object's speed divided by the time it takes.
Aristotle said that the spherical shape of the Earth was -due to air pressure pushing everything inward. -something that could not be explained or understood. -unstable since small deviations from it would grow larger. -the natural result of gravity pulling everything toward a center.
-the natural result of gravity pulling everything toward a center.
The Summer Solstice is the time when -the noon sun is highest in the sky. -the sun crosses the Celestial/Equator. -the noon sun is lowest in the sky.
-the noon sun is highest in the sky.
One reason that temperatures are higher in the summer is that -the sun is lower in the sky in the summer. -the sun is farther to our hemisphere in the summer. -the sun is higher in the sky in the summer. -the sun is closer to our hemisphere in the summer.
-the sun is higher in the sky in the summer.
A sidereal day is -the time it takes for the Sun to come back to the same positions in the sky. -exactly 24 hours. -the time it takes for the stars to come back to the same position in the sky. -the time it takes for the Moon to come back to the same positions in the sky.
-the time it takes for the stars to come back to the same position in the sky.
The purpose of a scientific model is -to predict the results of observations on real systems. -none of these answers. -to be attractive and elegant. -to be fun to play with.
-to predict the results of observations on real systems.
So far (as of 2011), the planet Mercury has been visited by -no successful space probes. -two successful space probes. -about 20 successful space probes. -just one successful space probe.
-two successful space probes.
Which of the following phases of the moon would be seen high in the south at dawn? -full. -waxing crescent. -waning quarter. -waning crescent.
-waning quarter.
Which of the following phases of the Moon would be seen high in the south at sunset? -waning crescent. -waxing quarter. -full. -waning quarter.
-waxing quarter.
The sun sets in the -ocean -east -north -west
-west
A disadvantage of the flat Earth model is that it fails to provide a complete explanation of -what holds up the surface of the Earth. -what causes the Sun to rise and set. -the existence of oceans. -the retrograde motion of the planets.
-what holds up the surface of the Earth.
The Law of Inertia says that if an object is not acted on by any outside force, its acceleration -can have any value at all. -will always be a constant. -will always be zero. -will be zero if the object is at rest and not zero if the object is moving.
-will always be zero.
If an object is moving at constant speed in a straight line, its acceleration is -zero. -negative in its direction of motion. -changing. -positive in its direction of motion.
-zero
An ion rocket engine produces 20 Newton of thrust. What acceleration can it give to a space probe with a mass of 105 kg?
0.1905
What total force will cause an object with a mass of 70-kg to gain 2.5-meter per second every second?
175 Newtons
the solid ball would hit the ground long before the hollow ball.
Aristotle would predict that
-Ursa Minor (contains Polaris and the Little Dipper) -Ursa Major (contains the Big Dipper) -Cepheus -Casseopeia
Circumpolar constellations
Force Formula
F=ma
A line drawn from a planet to the sun sweeps out equal areas in equal times.
Kepler's 2nd Law of Planetary Motion
For each planet, let T be the time that planet takes to go once around the Sun and let R be that planets average distance from the Sun. More precisely, R is half of the longest diameter of the planets elliptical orbit. The quantity T2/R3 has the same value for every planet.
Kepler's 3rd Law of Planetary Motion
That did not put the Earth at the center of the universe. It was offset from the centers of the various circles that described the motion of the planets.
The final version of the Ptolemaic System.
The Earth goes around the Sun. That put the Sun at the center of the universe and we would all fall off the Earth and into the Sun.
The model of Aristarchus
constellations that circle the Celestial Poles and never rise or set
circumpolar constellations?