What nationality was the man who determined that light has a finite speed?
Rømer's determination of the speed of light Rømer's determination of the speed of light was the demonstration in 1676 that light has a finite speed, and so does not travel instantaneously. The discovery is usually attributed to Danish astronomer Ole Rømer (1644–1710), who was working at the Royal Observatory in Paris at the time.
Andrew Gray (physicist) Dr Andrew Gray {'1': ", '2': ", '3': 'FRS FRSE', '4': "} (2 July 1847 – 10 October 1925) was a Scottish physicist and mathematician.