World line
World line is a term used in the theory of relativity and describes the trajectory of an object in space-time .
The world lines of freely falling objects, i.e. objects that are only subject to gravitation , are geodesics in curved space-time according to the general theory of relativity . This also applies to objects whose spatial paths are closed. In a reference system that is at rest relative to the sun, the world line of the earth is a helical line whose axis is the time axis.
In connection with the special theory of relativity , the concept of the world line was introduced by Hermann Minkowski in 1908 (see also Minkowski diagram ). World lines for massless particles lightlike and for mass-prone properties is time-like .
The concept can be generalized to higher-dimensional objects. The movement of a one-dimensional string through space-time results in a world plane, a two-dimensional object can be assigned a world volume , etc.
Individual evidence
- ^ Paul A. Tipler , Ralph A. Llewellyn: Modern Physics. Oldenbourg Publishing House, 2002, ISBN 978-3486255645 .
- ↑ A. Friedmann , G. Singer: The world as space and time. Verlag Harri Deutsch, 3rd edition, 2006, p. 124, page no longer available , search in web archives: Google Books.