History
| 1675 | Rømer and Huygens, moons of Jupiter | 220,000 |
| 1729 | James Bradley, aberration of light | 301,000 |
| 1849 | Hippolyte Fizeau, toothed wheel | 315,000 |
| 1862 | Léon Foucault, rotating mirror | 298,000±500 |
| 1907 | Rosa and Dorsey, EM constants | 299,710±30 |
| 1926 | Albert Michelson, rotating mirror | 299,796±4 |
| 1950 | Essen and Gordon-Smith, cavity resonator | 299,792.5±3.0 |
| 1958 | K.D. Froome, radio interferometry | 299,792.50±0.10 |
| 1972 | Evenson et al., laser interferometry | 299,792.4562±0.0011 |
| 1983 | 17th CGPM, definition of the metre | 299,792.458 (exact) |
Until the early modern period, it was not known whether light travelled instantaneously or at a very fast finite speed. The first extant recorded examination of this subject was in ancient Greece. The ancient Greeks, Muslim scholars and classical European scientists long debated this until Rømer provided the first calculation of the speed of light. Einstein's Theory of Special Relativity concluded that the speed of light is constant regardless of one's frame of reference. Since then, scientists have provided increasingly accurate measurements.
Read more about this topic: Speed Of Light
Famous quotes containing the word history:
“In history the great moment is, when the savage is just ceasing to be a savage, with all his hairy Pelasgic strength directed on his opening sense of beauty;—and you have Pericles and Phidias,—and not yet passed over into the Corinthian civility. Everything good in nature and in the world is in that moment of transition, when the swarthy juices still flow plentifully from nature, but their astrigency or acridity is got out by ethics and humanity.”
—Ralph Waldo Emerson (1803–1882)
“What you don’t understand is that it is possible to be an atheist, it is possible not to know if God exists or why He should, and yet to believe that man does not live in a state of nature but in history, and that history as we know it now began with Christ, it was founded by Him on the Gospels.”
—Boris Pasternak (1890–1960)
“This above all makes history useful and desirable: it unfolds before our eyes a glorious record of exemplary actions.”
—Titus Livius (Livy)