Question

Which does the shift of the hydrogen absorption spectrum of a galaxy provide evidence for? Select the three correct answers.(2 points)
Responses

composition of the universe
composition of the universe

motion of the galaxy
motion of the galaxy

temperature of the galaxy
temperature of the galaxy

number of stars in the galaxy
number of stars in the galaxy

expansion of the universe
expansion of the universe

The Big Bang theory
The Big Bang theory

Answer 1

The shift of the hydrogen absorption spectrum of a galaxy provides evidence for the following three correct answers:

1. **Motion of the galaxy** - The redshift or blueshift of spectral lines indicates whether a galaxy is moving away from or towards us.

2. **Expansion of the universe** - The observed redshift of distant galaxies is evidence for the expansion of the universe, as it shows that galaxies are moving away from us over time.

3. **The Big Bang theory** - The redshift of galaxies supports the Big Bang theory, which posits that the universe has been expanding since its creation.

So, the correct answers are:
- Motion of the galaxy
- Expansion of the universe
- The Big Bang theory