In physics, the twin paraox is a thought experiment in Special Relativity, in which a person who makes a journey into space in a high-speed rocket will return home to find he or she has aged less than an identical twin who stayed on Earth. This result appears puzzling, since the situation seems symmetrical, as the latter twin can be considered to have done the travelling with respect to the former. Hence it is called a "paradox". In fact, there is no contradiction and the apparent paradox is explained within the framework of relativity theory, and has been verified experimentally using precise measurements of clocks flown in airplanes.