- #1
PhDnotForMe
- 56
- 3
- TL;DR Summary
- How we measure galactic rotation
How have we been able to measure galactic rotation? I have seen graphs showing the relation between the velocity of stars in a galaxy and their distance from the center. These graphs show that the observed velocities of stars are much faster than they are expected to be, particularly ones that are farther from the center and they use dark matter to explain it. Do we look at our own galaxy or do we look at other galaxies? How are we so sure? Any links would be greatly appreciated.