- Ghenghiz Cohen, known as Cohen the Barbarian, is a hero in the classical sense, i.e., a professional thief, brawler and ravisher of women. Cohen is introduced in the second Discworld novel, The Light Fantastic, with significant returns in Interesting Times and then with his last appearance in The Last Hero. His name and character are an obvious echo of Robert E. Howard’s Conan the Barbarian and Genghis Khan, and of the common Jewish surname Cohen.
- Bell’s theorem (Wikipedia)
Bell’s theorem is a term encompassing a number of closely related results in physics, all of which determine that quantum mechanics is incompatible with local hidden-variable theories, given some basic assumptions about the nature of measurement. “Local” here refers to the principle of locality, the idea that a particle can only be influenced by its immediate surroundings, and that interactions mediated by physical fields cannot propagate faster than the speed of light. “Hidden variables” are supposed properties of quantum particles that are not included in quantum theory but nevertheless affect the outcome of experiments. In the words of physicist John Stewart Bell, for whom this family of results is named, “If [a hidden-variable theory] is local it will not agree with quantum mechanics, and if it agrees with quantum mechanics it will not be local.”