Compact discs are optical discs used for storing digital data. They are made of polycarbonate plastic coated with a much thinner layer of super purity aluminum, protected by a film of lacquer. The information on a standard CD is encoded as a spiral track of "pits" molded into the top of the polycarbonate layer. The areas between pits are known as "lands." A change from pit to land indicates the 1, and no change indicates the 0, of binary code. What is the size of a pit?
E. M. Forster
Back in the day
Known as the Lockerbie bombing, the destruction of Pan Am Flight 103 killed 270 people from 21 countries, including 11 people on the ground. After a three-year joint investigation by the Scottish Constabulary and the US FBI, during which 15,000 witness statements were taken, indictments for murder were issued against two Libyans, one of whom was an intelligence officer. A number of people, several of them famous, accidentally missed the flight due to tardiness or other reasons; who were they?
Born on a day like today
Stalin ruled the Soviet Union from the mid 1920s to 1953, turning the fledgling Communist nation into a totalitarian state. Under his rule, the collectivization of Russian farmers helped the nation become an industrial power, but millions were killed in the process. He allied with Britain and the US to defeat the Axis Powers and later took control of Eastern Europe. Stalin's use of mass repression and a "personality cult" was repudiated by future Soviet leaders. What does "Stalin" mean?