Author Question: What does Hubble's law tell us? A) The longer the period of a Cepheid variable, the greater its ... (Read 72 times)

imowrer · **on:** Jul 27, 2018

What does Hubble's law tell us?

A) The longer the period of a Cepheid variable, the greater its luminosity.
B) The more distant a galaxy, the faster it is moving away from us.
C) The faster a spiral galaxy's rotation speed, the more luminous it is.
D) For every force, there is an equal and opposite reaction force.

Question 2

The density wave theory attempts to explain why the spiral arm structure persists over a long time.

Indicate whether the statement is true or false