Lesson 2: Astronomers after the Dark Ages

Multiple Choice

What was the main reason Aristarchus thought the sun should be at the center of the universe, and why did people at the time reject this idea?

• Because the sun was bigger than the earth, but people couldn't measure the parallax of stars

• Because the earth was believed to be flat

• Because the moon was thought to be the center

• Because the stars were brighter than the sun

Multiple Choice

Which of the following statements about Copernicus' heliocentric model is correct?

• It placed the Sun at the center of the universe and was influenced by Aristarchus' work.

• It placed the Earth at the center of the universe.

• It was based on the idea that planets do not move.

• It was developed before Ptolemy's model.

Multiple Select

Which feature did Copernicus retain from Ptolemy's geocentric system in his own model?

• Equants (the sun is slightly off-center)

• Epicycles

• Sun at the exact center

• A central fire in which all objects orbit

Fill in the Blanks

The Copernican model places the

at the center of the universe.

Multiple Choice

What was one major disadvantage of the Copernican system according to the slides?

• It could not explain the lack of parallax motion for stars.

• It used elliptical orbits for planets.

• It did not require epicycles.

• It gave a more natural explanation of retrograde motion.

Multiple Select

Which of the following statements about Tycho Brahe are correct? Select all that apply.

• He believed in a geocentric universe.

• He made precise observations of Mars.

• He explained the peculiarities in Mars' motion.

• He believed in a heliocentric solar system.

Multiple Choice

According to Tycho Brahe's cosmological model, which of the following statements is correct?

• The Earth orbits the Sun, and all planets orbit the Sun.

• The Sun and all planets orbit the Earth.

• The planets orbit the Sun, but the Sun and stars orbit the Earth.

• All planets, including the Sun, orbit the Earth.

Fill in the Blanks

Tycho Brahe hired Johannes

to help revise tables of planetary positions.

Multiple Choice

According to Kepler's First Law, where does the sun sit in a planet's orbit?

• At the center of the orbit

• At one of the two foci

• Outside the orbit

• At the edge of the orbit

Fill in the Blanks

Galileo Galilei was the first to use the

to study the sky and record his observations.

Multiple Select

Select all important contributions to Astronomy that Galileo was able to document through his observations using the telescope.

• The moon has mountains and valleys

• Planets move about the sun in elliptical orbits

• Jupiter is surrounded by 4 moons that shows not all objects orbit Earth

• Sunspots show that the Sun rotated

Multiple Choice

Which astronomer published a book that was banned by the Spanish inquisition and and was imprisoned in 1633?

• Galileo

• Newton

• Copernicus

• Kepler