Homework - The Origin of Modern Astronomy (Conceptual)
Copernicus changed the place of Earth by devising a heliocentric model of the cosmos. Based Copernicus and the heliocentric system, select all of the correct statements from the following list.
-Copernicus's model featured multiple motions of Earth. -Copernicus's heliocentric model provided a simple explanation for retrograde motion.
Evidence of how the ancients described the placement of Earth is found partly through archaeoastronomy, the study of the astronomy of ancient peoples, and through history beginning with the ancient Babylonians and Greeks. Based on ancient astronomy, select all of the correct statements from the following list.
-Eratosthenes accurately estimated the diameter of the Earth. -Classical philosophers believed that Earth was the center of the universe. -Classical philosophers believed that Earth did not move.
Galileo made many observations about the heavens, and was also condemned by the Church. Based on his discoveries and the case against him, select all of the correct statements from the following list.
-Galileo's trial was more about his disrespect of authority than his teachings of astronomy. -Galileo's case has recently been reexamined by the Catholic Church. -Galileo observed craters on the moon and sunspots on the sun.
Based on Tycho's observations and Kepler's discoveries regarding planetery motion, select all of the correct statements from the following list.
-Kepler found that the speed of a planet varied throughout its orbit. -Tycho made most of the observations used by Kepler. -Kepler discovered that planetary orbits are elliptical, not circular.
The 99 years between the deaths of Copernicus and Galileo saw the birth of science in its modern form. Select all of the correct statements from the following list.
-The birth of modern astronomy was also really the birth of modern science. -Many fields were going through major changes at the time that astronomy and science in general were evolving to their modern forms. -Modern science depends on evidence to test theories. -Kepler and Galileo were among the first to make scientific predictions based on data analysis and observation.
f you lived on Mars, which planets would exhibit retrograde motion
-Uranus - Saturn - Jupiter - Neptune
What does Kepler's second law indicate about the orbital speed of a planet?
A planet moves at its fastest when it is closest to the sun.
Who taught that the Earth is stationary and at the center of the universe with the sun, the moon, and the planets moving around Earth in perfect circles?
Aristotle (384-322 bc)
Kepler's Second Law, Orbital Velocity I. In the figure below, Kepler's second law is depicted. A planet moves from A'→B' in one month and from A→B in one month. Path A to B is longer than path A'→B'. Using this information, along which path is the planet traveling faster?
A→B
Below is a postage stamp with a picture of a scientist holding an astronomical model. Who developed this theoretical model?
Copernicus
Why did Copernicus use epicycles in his system?
Copernicus insisted on circular motions and needed epicycles to reproduce minor variations in motions of planets.
How did Claudius Ptolemy account for the retrograde motion of the planets?
Each planet moves on an epicycle that in turn moves on a deferent that circles around Earth.
Which of the "First Principles of Ancient Astronomy" did Kepler's laws contradict?
Earth is at the center of the universe and all heavenly motion is uniform and circular.
Who accurately determined the size of Earth by considering Sun angles at Syene and Alexandria?
Eratosthenes (c. 200 BC)
Which of the following scientists was condemned by the Catholic Church?
Galileo
How was Tycho Brahe able to make more accurate astronomical measurements than had been made before his time?
He designed and used large devices to measure small angles.
What effect did Plato's proposal have on future astronomers?
His idea of a sphere being the most perfect geometric form influenced astronomical theories for literally hundreds of years.
How did Nicolaus Copernicus account for the retrograde motion of the planets? .
Inner planets orbit the sun faster and pass outer planets as they orbit around the sun
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. Which of the following is true for the explanation of the phases of Venus in Tycho's model?
It agrees with Galileo's telescopic observations, because Venus at times is farther away from Earth than the sun.
How did Kepler's first law of planetary motion alter the Copernican system?
It changed the perfect circles to ellipses and it placed the sun at one focus of each orbit.
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. Which of the following is true for the explanation of the phases of Venus in Tycho's system?
It matched Galileo's telescopic observations.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery of craters on the moon contradict Ptolemaic theory?
It showed that a heavenly body was not perfect.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery of sunspots contradict Ptolemaic theory?
It showed that a heavenly body was not perfect.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery of the moons of Jupiter contradict Ptolemaic theory?
It showed that not everything orbited Earth.
In 1572, Tycho observed a brilliant "new star," now called Tycho's supernova. What was a result of his failure to detect a parallax shift for this star?
It undermined his belief in the Ptolemaic system, because it meant that the star was far enough away to be part of the "fixed background" of stars, which should be unchanging.
Galileo made several important telescopic discoveries. How did Galileo's telescopic discovery that Venus went through the same cycle of phases as the moon contradict Ptolemaic theory?
It was possible in Copernican theory, but not Ptolemaic theory
Planet Phases. If you lived on Mars, which planets would never be visible at crescent phases? ________.
Jupiter Saturn Uranus Neptune
Planet Retrograde Motion I. If you lived on Mars, which planets would describe retrograde loops?
Jupiter Saturn Uranus Neptune
Galileo's discovery of four moons orbiting Jupiter showed that planetary bodies could move and carry moons. This supports the model of the universe presented by whom of the following?
Nicolaus Copernicus
The phases of Venus observed by Galileo support the model of the universe presented by which of the following?
Nicolaus Copernicus
Which represents an unchangeable truth?
None of these choices are correct.
In 1572, Tycho observed a brilliant "new star," now called Tycho's supernova. Which is true about Tycho's "Tychonic" system?
Planets orbited the sun, which orbited Earth.
Which list below has the life and work of the following scientists in chronological order, from left to right?
Ptolemy, Copernicus, Tycho, Galileo
Why is Stonehenge thought to be an ancient astronomical observatory?
Stones are aligned with significant rising and setting positions.
Galileo's telescopes were not of high quality by modern standards. When Jupiter was closest to Earth, he was able to see its disk and moons, but he never reported seeing the disk or features on Mars. What is a good explanation for this difference? (Hints: Use the small-angle formula to find the angular diameter of Mars when it is closest to Earth. How does that compare with the maximum angular diameter of Jupiter? [Assume circular orbits with radii equal to the average distance from the sun.] At its closest, Jupiter is 4 AU from Earth and Mars is 0.5 AU from Earth. Jupiter is 0.000477 AU and Mars is 0.0000226 AU in diameter.)
The angular size of Mars is smaller than the angular size of Jupiter.
What did Plato propose about all heavenly motion?
The motion is in circular paths.
The figure shown here illustrates how to draw an ellipse with two tacks and a loop of string. Imagine constructing a new ellipse using the same string but with the distance between the two pins reduced to zero. Which statement below is true?
The new ellipse is a circle.
The figure shown here illustrates how to draw an ellipse with two tacks and a loop of string. Imagine constructing a second ellipse using the same string but with the distance between the two tacks increased by 10%. How does this second ellipse compare to the original ellipse shown here?
The second ellipse is more elliptical than the original ellipse.
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth. How did the epicycles of Mercury and Venus differ from those of Mars, Jupiter, and Saturn?
Their centers had to always be on the line between Earth and the sun.
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. In Tycho's model, the phases of Venus were which of the following?
They were the same as in the Copernican model.
In Tycho's model of the universe, the moon and the sun orbited Earth, and all the planets orbited the sun. Which of the following is true for Galileo's telescopic observation of the phases of Venus?
They were the same as the explanation in two of these models.
When Tycho observed the new star of 1572, he could detect no parallax. Why did that result undermine belief in the Ptolemaic system?
This star is farther away than the moon and thus the heavens are not perfect and unchanging
Whose observatory is shown in the figure below?
Tycho's
If you lived on Mars, which planet would be visible as a crescent phase?
Venus
Below is a postage stamp with a picture of a scientist holding an astronomical model. What is the larger circle in his model?
a deferent
Galileo's telescope showed him that Venus has a large angular diameter of 61 seconds of arc when it is a crescent; a small angular diameter of 10 seconds of arc when it is nearly full and, finally, when Venus is "half full," an angular size of 59 seconds of arc. At which point described below is Venus closest to the Earth?
a large angular diameter of 61 seconds of arc when it is a crescent
Which is a theory that has been refined, tested, and confirmed so often that scientists have great confidence in it?
a natural law
The quantitative numerical result of Kepler's research was
a set of tables giving future positions of the planets.
Which is a system of rules and principles that can be applied to a wide variety of circumstances?
a theory
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth.
all of the known planets
Below is a postage stamp with a picture of a scientist holding an astronomical model. What is the smaller circle in his model?
an epicycle
Evidence of early prehistoric human cultures observing astronomical phenomena exists in which of the following?
archaeoastronomical sites
The diagram below shows a view of the eastern horizon (horizontal line --------) with the direct eastern horizon point labeled B. The direction to points northeast of the direct east point is labeled with an A and an arrow. The point southeast of the direct east point is labeled with a C and an arrow. A B C ------------------EAST------------------ For a mid-latitude northern hemisphere observer, what point corresponds to the rising point of the sun on the date of the autumnal equinox?
b
The diagram below shows a view of the eastern horizon (horizontal line --------) with the direct eastern horizon point labeled B. The direction to points northeast of the direct east point is labeled with an A and an arrow. The point southeast of the direct east point is labeled with a C and an arrow. A B C ------------------EAST------------------ For a mid-latitude northern hemisphere observer, what point corresponds to the rising point of the sun on the date of the vernal equinox?
b
Why did Plato propose what he did about heavenly motion and the shape of heavenly objects?
because he believed the sphere to be the most perfect geometrical form
Why didn't Copernicus's system predict the positions of planets any better than Ptolemy's?
because he used circular orbits
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth. Why did the centers of the epicycles of Mercury and Venus have to remain on the line between Earth and the sun?
because they were never seen very far from the sun in the sky
Plato proposed that all heavenly motion is which of the following?
both circular and uniform
Galileo's telescope showed him that Venus has a large angular diameter (61 seconds of arc) when it is a crescent and a small angular diameter (10 seconds of arc) when it is nearly full. When Venus is "half full," its angular size is about 59 seconds of arc.
circles the sun.
Gravitational Force, Body A, B I. Body A has the same mass as Body B and is located a distance d from Body B. If Body A is moved further away from Body B by twice as much, did the gravitational force increase, decrease, or stay the same?
decrease
Which of these two figures matches the phases of Venus observed by Galileo?
figure b (right)
Gravitational Force, Body A, B, C I. If Body A is twice as massive as Body B and both bodies are at the same distance from Body C, is the force of gravity between Body A and Body C greater than, less than, or equal to the force of gravity between Body B and Body C?
greater than
Why did the model of the universe proposed by Copernicus gain support soon after its publication?
it was a more elegant explanation of retrograde motion
Newton's Second Law I. Two equal body masses are accelerated, but Body A's acceleration is half of Body B's. Is the force on Body A greater, less than, or equal to the force on Body B?
less than
What phases of Venus are predicted by the Ptolemaic system?
new and crescent phases only
What phases of Venus were observed by Galileo?
new, crescent, quarter, gibbous, and full phase
Which set of astronomical tables is based on Ptolemy's model?
the Alfonsine tables
Which set of astronomical tables is based on the Copernican model?
the Prutenic tables
Which set of astronomical tables was developed most recently?
the Rudolphine tables
Which set of astronomical tables were considered most accurate?
the Rudolphine tables
Which set of astronomical tables were worked on by Tycho and Kepler?
the Rudolphine tables
Which is not an archaeoastronomical site?
the island of Hveen
One of the first principles of ancient astronomy is that the heavens beyond _____ are perfect, and the Earth is corrupt
the moon
In Ptolemy's mathematical model of planetary motion, a planet was on a circular path, known as an epicycle, whose center was on another circular path, a deferent, that was centered on Earth. What were epicycles used to describe?
the retrograde motion of planets
Below is a postage stamp with a picture of a scientist holding an astronomical model. Which object is the central figure in the model?
the sun
What was the most important contribution of Tycho Brahe to modern astronomy?
twenty years of accurate measurements of planetary positions
What feature of Aristotle's model of the universe was included in the model proposed by Copernicus?
uniform circular motion
