Week 7, clip 12

Timepoint:  14:02.5

1) Which of the following examples can be affected by Hubble flow (cosmological expansion of space)?  Check all that apply.

- Distant galaxies moving away from Earth.
- Galaxies rapidly orbiting the center of mass in a galaxy cluster.
- Colliding galaxies.
- Earth's orbit around the Sun increasing in radius.

Answers:
1) Distant galaxies moving away from Earth.