What nationality was the man who determined that light has a finite speed?
Ole Rømer Ole Christensen Rømer (] ; 25 September 1644 – 19 September 1710) was a Danish astronomer who in 1676 made the first quantitative measurements of the speed of light.
Manne Siegbahn Karl Manne Georg Siegbahn {'1': ", '2': ", '3': 'ForMemRS', '4': "} (3 December 1886 – 26 September 1978) was a Swedish physicist who was awarded the Nobel Prize in Physics in 1924 "for his discoveries and research in the field of X-ray spectroscopy".