PHYS 3310 Module 2 Activity 1

How fast and in what direction must galaxy A be moving if an absorption line found at wavelength 550 nm (green) for a stationary galaxy is shifted to 450 nm (blue) (a “blue-shift”) for galaxy A?

Calculate, for the judge, how fast were you going when you ran the red light because it appeared Doppler-shifted green to you. (Wavelengths: Red: 650nm, Green: 550nm)

All galaxies farther away than about 50 × 10⁶ ly exhibit a red shift in their emitted light that is proportional to distance, with those farther and farther away having progressively greater red shifts. What does this imply, assuming that the only source of red shift is relative motion?