Definition of relativity
1a : the quality or state of being relativeb : something that is relative
2 : the state of being dependent for existence on or determined in nature, value, or quality by relation to something else
3a : a theory which is based on the two postulates (1) that the speed of light in a vacuum is constant and independent of the source or observer and (2) that the mathematical forms of the laws of physics are invariant in all inertial systems and which leads to the assertion of the equivalence of mass and energy and of change in mass, dimension, and time with increased velocity —called also special relativity, special theory of relativityb : an extension of the theory to include gravitation and related acceleration phenomena —called also general relativity, general theory of relativity
4 : relativism 1b
Recent Examples of relativity from the Web
That seems like a bit of a stretch, so astronomers long ago reached a much more simple conclusion, one powered by the newfangled general theory of relativity : the space itself between galaxies is expanding, and galaxies are just along for the ride.
The genius behind the theory of relativity is regularly credited with discovering a clever accounting rule for investments then reeling off a witty quote to go with it.
Albert Einstein is justly famous for devising his theory of relativity, which revolutionized our understanding of space, time, gravity, and the universe.
One of the yellowing pages, bearing Einstein’s signature and embossed seal, and a handwritten general relativity equation, opens at $8,000 and is expected to sell for at least twice that.
One of the yellowing pages, bearing Einstein's signature and embossed seal, and a handwritten general relativity equation, opens at $8,000 and is expected to sell for at least twice that.
Relativity predicted that the mass of the Sun should distort space enough to bend the light arriving from distant stars.
Before general relativity, the only thing that could have explained this eccentric behavior would have been another planet’s gravity, an imaginary planet that Neptune predictor Urbain Le Verrier called Vulcan.
Einstein’s theory of general relativity perfectly explained Mercury’s 43 arcsecond procession.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'relativity.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
First Known Use of relativity
RELATIVITY Defined for English Language Learners
Definition of relativity for English Language Learners
physics : a theory developed by Albert Einstein which says that the way that anything except light moves through time and space depends on the position and movement of someone who is watching
Seen and Heard
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