Vincent Black Shadow to the new specifications. The prototype Black Shadow had engine number F10AB/1B/558 in frame R2549, and was completed on 16 February 1948. The bike was road tested by Charles Markham in Motor Cycling May 1948, during which test the bike was reported to have reached . The Black Shadow was officially introduced at the 1948 Motorcycle Show at Earls Court in London. The Black Shadows were built with the same labour-intensive hand-fitting of bearings and major engine parts that Vincent had used prior to the war. Official records say that 1774 Vincent Black Shadows were made. Vincent also built 15
Nonsingular black hole models Nonsingular black hole models A nonsingular black hole model is a mathematical theory of black holes that avoids certain theoretical problems with the standard black hole model, including information loss and the unobservable nature of the black hole event horizon. For a black hole to physically exist as a solution to Einstein's equation, it must form an event horizon in finite time relative to outside observers. This requires an accurate theory of black hole formation, of which several have been proposed. In 2007, Shuan Nan Zhang of Tsinghua University proposed a model in which the event horizon of a potential