Olympiad beginning on the opening of the Olympic Games for the summer sports. The first modern Olympiad began in 1896, the second in 1900, and so on (the 31st began in 2016: see the Olympic Charter). The ancient and modern Olympiads would have synchronised had there been a year zero between the Olympiad of 4 BC and the one of 4 AD. But as the Gregorian calendar goes directly from 1 BC to 1 AD, the ancient Olympic cycle now lags the modern cycle by one year. An ancient Olympiad was a period of four years grouped together, counting inclusively as
United States National Physics Olympiad United States National Physics Olympiad The United States National Physics Olympiad (USAPhO) is a high school physics competition run by the American Association of Physics Teachers and American Institute of Physics to select the team to represent United States at the International Physics Olympiad (IPhO). The team is selected through a series of exams testing their problem solving abilities. Approximately the top 20 finalists are invited to a rigorous study camp at University of Maryland to prepare for the IPhO. The International Physics Olympiad began in 1967 among Eastern European countries and many western countries soon joined in the 1970s.