A Brief History of Relativity (Cont.)

Part 5 Einstein's Ideas

     As it was known throughout the 20th century, Einstein re-imagined and completely changed some of the most prominent scientific thought of his time. However, he was not done there with his theory of relativity and E=MC2, for once his gears started moving, so did the rest of the scientific world. There was one fault to Einstein's theory of relativity though, and that was even though the theory coincided with the laws of electricity and magnetism, it was not compatible with Newton's law of gravity. As stated in the book, it says that this law explains "that if one changed the distribution of matter in one region of space, the change in the gravitational field would be left instantaneously everywhere else in the universe." With this law, it essentially means that we could send signals faster (which is forbidden by the law of relativity) through out the universe. It also, meant that there had to be a required existence of universal time, which the theory of relativity also abolished. Once Einstein returned to Prague in 1911, this is when he seriously put some thought into deciding what he could do to solve the problem and this is what he deduced.

       There is an actual tight relationship between gravitational fields and acceleration, and so he came up with this example of a man within an elevator. He said to imagine someone inside a closed box, such as the elevator, the individual inside could not tell if that box or elevator in this case  was at rest due to Earth's gravitational field. Also, one could not even accelerate in that matter or free fall at an extreme distance within the elevator due to confinement. As a result of this conclusion Einstein, upon his return to Zurich in 1912, discovered that the there will be an equivalence with acceleration and gravitational fields only if the geometry of space time was curved and not flat.

 To put it in other words, for example, from the book, objects such as an apple or planet would try to move in a very straight and forward line through space time, but due to the gravitational fields, their paths would seem to appear to bent because space time itself is curved. Eventually after this study, Einstein collaborated with Marcel Grossman, to write a joint paper putting out the idea that what is known as a gravitational field to us, is simply a result to due the curvature of space time.