そうたいせいろん 相対性理論
1. theory of relativityPhysics terminology, See also 相対論 そうたいろん
Wikipedia definition
2. Theory of relativityThe theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity. The basic overall concept is that both time and space are relative, not fixed. However, the word relativity is sometimes used in reference to Galilean invariance. The term "theory of relativity" was based on the expression "relative theory" used by Max Planck in 1906, who emphasized how the theory uses the principle of relativity.
Read “Theory of relativity” on English Wikipedia
Read “相対性理論” on Japanese Wikipedia
Read “Theory of relativity” on DBpedia


to talk about this word.