Chapter 37: Q99P (page 1152)
A spaceship approaches Earth at a speed of 0.42c. A light on the front of the ship appears red (wavelength 650 nm) to passengers on the ship. What (a) wavelength and (b) color (blue, green, or yellow) would it appear to an observer on Earth?
Short Answer
(a) The wavelength of light for observer on Earth is
(b) The color of light for observer on Earth is blue.