General Relativity
CTCs appear in locally unobjectionable exact solutions to the Einstein field equation of general relativity, including some of the most important solutions. These include:
- the Misner space (which is Minkowski space orbifolded by a discrete boost)
- the Kerr vacuum (which models a rotating uncharged black hole)
- the interior of a rotating BTZ black hole
- the van Stockum dust (which models a cylindrically symmetric configuration of dust)
- the Gödel lambdadust (which models a dust with a carefully chosen cosmological constant term)
- the Tipler cylinder (a cylindrically symmetric metric with CTCs)
- Bonnor Steadman solutions describing laboratory situations such as two spinning balls
- J. Richard Gott has proposed a mechanism for creating CTCs using cosmic strings.
Some of these examples are, like the Tipler cylinder, rather artificial, but the exterior part of the Kerr solution is thought to be in some sense generic, so it is rather unnerving to learn that its interior contains CTCs. Most physicists feel that CTCs in such solutions are artifacts.
Read more about this topic: Closed Timelike Curve
Famous quotes containing the words general and/or relativity:
“In communist society, where nobody has one exclusive sphere of activity but each can become accomplished in any branch he wishes, society regulates the general production and thus makes it possible for me to do one thing today and another tomorrow, to hunt in the morning, fish in the afternoon, rear cattle in the evening, criticize after dinner, just as I have a mind, without ever becoming hunter, fisherman, shepherd or critic.”
—Karl Marx (1818–1883)
“By an application of the theory of relativity to the taste of readers, to-day in Germany I am called a German man of science, and in England I am represented as a Swiss Jew. If I come to be regarded as a bête noire the descriptions will be reversed, and I shall become a Swiss Jew for the Germans and a German man of science for the English!”
—Albert Einstein (1879–1955)