THEORY OF RELATIVITY BY ALBERT EINSTEIN

ABSTRACT

The theory of relativity, or simply relativity in physics, usually encompasses two theories by Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space contracts and time dilates; Spacetime: space and time should be considered together and in relation to each other; Space is a physical entity that can be changed, space is not just nothing, space can affect mass (gravity; The speed of light is nonetheless invariant, the same for all observers. 

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