Definition of "theory of relativity" []

• The generic term of the special relativity and the general relativity, two theories in physics developed mainly by Albert Einstein at the beginning of the 20th century from which several important results such as the equivalence of matter and energy and the Einstein field equations are derived. (noun)

Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License

• "Einstein’s theory of relativity offers both the promise of unlimited energy and the specter of complete annihilation,5 and it led to a fundamental shift in the way that we view our world and ourselves."