Speed of light special theory of relativity, in which the speed of light in vacuum "c" featured as a fundamental constant, also appearing in contexts unrelated to light. This made the concept of the stationary aether (to which Lorentz and Poincaré still adhered) useless and revolutionized the concepts of space and time. In the second half of the 20th century much progress was made in increasing the accuracy of measurements of the speed of light, first by cavity resonance techniques and later by laser interferometer techniques. These were aided by new, more precise, definitions of the metre and second. In 1950, Louis Essen
Speed of Darkness fiction, named The Science of Discworld, written by Terry Pratchett, Ian Stewart and Jack Cohen. In a 2011 interview on BBC Radio 1, frontman Dave King explained that the title track and album title was taken from a quote of Dino Misetić, the artist who designed the album cover, which appeared in the book Sarajevo Marlboro. Dino, who grew up in the Balkans during the Balkan Wars, is quoted in the book, saying: "They taught us what the speed of light is, but nobody can teach you what the speed of darkness is." Flogging Molly: Additional musicians: Speed of Darkness