Author Question: How did the Ptolemaic model explain the apparent retrograde motion of the planets? A) The planets ... (Read 66 times)

nenivikky · **on:** Jul 27, 2018

How did the Ptolemaic model explain the apparent retrograde motion of the planets?

A) The planets moved along small circles that moved on larger circles around Earth.
B) The planets sometimes stopped moving and then reversed to move backward along their circular orbits.
C) The model showed that apparent retrograde motion occurs as Earth passes by another planet in its orbit of the Sun.
D) The planets resided on giant spheres that sometimes turned clockwise and sometimes turned counterclockwise.

Question 2

How does the age of the universe depend on Hubble's constant, and why?

What will be an ideal response?

leahchrapun · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

A

Answer to Question 2

The larger the value of Hubble's constant, the younger is the universe. This is because a larger value for Hubble's constant means the universe is expanding faster, which means it took less time to reach its current size.