Elongation of Moving Bodies
Year: 2003 Pages: 4
Keywords: special relativity, rod length, 4-dimensional geometry
It is marked that the special relativity theory correlates a four-component quantity to a material rod. The corresponding limiting transition from Minkowski's 4-geometry to Euclid's 3-geometry (justified in the rest frame) is provided by vanishing the time component. It is emphasized that the interval (pseudo-length) as a Lorentzian scalar must not depend on velocity. In particular, the space-like interval is equal to the rod length at rest. In a moving frame, its space part (the rod length in motion) because of the negative sign (pseudo-Euclideanness) is always greater than the interval itself. And this means that bodies elongate (but do not contract) in motion.