Jim stands at the front of a space ship at 90% of the speed of light and fires a laser gun forward. Jim’s ship is moving past Steve who sees the ship moving at 90% of the speed of light away from him. From Steve’s point of view the laser light leaving the gun moves at? A. 190% speed of light B. 10% C. 90% D. 100%
It's 100% (D). The speed of light is the same, in all frames of reference, and no matter whether the source or the observer is moving, or how fast, or in what direction, or for how long, or what day it is.
