Author Question: In Ptolemy's geocentric model, the planet's motion along its deferent is all that is needed to ... (Read 39 times)

tingc95 · **on:** Jul 27, 2018

In Ptolemy's geocentric model, the planet's motion along its deferent is all that is needed to understand retrograde motion.

Indicate whether the statement is true or false

Question 2

If the distance between us and a star is doubled, with everything else remaining the same, its luminosity

A) is decreased by a factor of two, and its apparent brightness is decreased by a factor of two.
B) remains the same, but its apparent brightness is decreased by a factor of four.
C) is decreased by a factor of four, and its apparent brightness is decreased by a factor of four.
D) remains the same, but its apparent brightness is decreased by a factor of two.
E) is decreased by a factor of four, but its apparent brightness remains the same.