Einstein's general theory of relativity

 

Einstein, a celebrated German-born theoretical physicist who spent the final years of his life at Princeton University in the northeastern United States, presented his theory on November 25, 1915 before the Prussian Academy of Science.

The document was published in March 1916 in a journal called Annalen der Physik.

The general theory of relativity was among the most revolutionary in history; it marked a major leap from the law of universal gravitation put forth by Sir Isaac Newton in 1687.

Einstein believed that "space and time are not fixed, which was what others had thought, but are flexible, dynamic phenomena like other processes of the universe," said Michael Turner, director of the Kavli Institute for Cosmological Physics.
"So space bends and time warps, and it was a whole new way at looking at gravity."

Einstein had put forth a more restrained version of his theory in 1905, the special theory of relativity, which left out gravity but described the relationship between space and time. It held that the speed of light is the same in a vacuum, and the laws of physics do not change regarding inert objects.

He also came up with his famous equation, E=mc2, which says that energy equals mass times the speed of light in a vacuum, squared. In other words, mass and energy are the same but in different forms.