A Brief Response to Jan Slowak's "Special Relativity and Length Contraction''

Jan Slowak’s paper Special Relativity and Length Contraction argues that length contraction presents a fundamental problem for special relativity. His argument is based on a thought experiment in which a body initially at rest relative to an inertial frame S is accelerated until it moves with constant velocity v relative to S. Slowak argues that the body must then “suddenly” change its length from its rest length to its Lorentz-contracted length. He also argues that it is problematic that the length-contraction formula contains neither t nor t′ . In this response, we show that neither objection is valid. Slowak's mistake arises from the well-spread confusion of a frame-dependent measurement of length with a physical deformation of the body.