Einstein and Relativity.

Albert Einstein electrified the physics, community in the United States with his special theory of relativity in 190S and his general theory of relativity in 1916. In his speci.il theory of relativity Einstein posited that space and time aie not ahsolure and independent realities. Indeed, the word relativity indicates that motion, space, and time cannot be measured from a fixed point but are relatne to the observer measuring them. The speed of light, however, is a constant in all frames of referenie. As an object approaches the speed of light, it appears to contract in the direction of motion: its mas*- increases; and time, as measured by a clock moving with the object, slows. Lulstein asserted that mass and energy are interchangeable properties: E=mc , where energy is said to be equivalent to mass times the square of the speed...