. . "The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its value is exactly 7008299792458000000\u2660299792458 metres per second (\u22487008300000000000000\u26603.00\u00D7108 m/s), as the length of the metre is defined from this constant and the international standard for time. According to special relativity, c is the maximum speed at which all matter and information in the universe can travel."@en . . . . .