Chapter 3 Part 3

Einstein's theories of relativity do not state that everything is relative, instead they stated that only somethings are relative and even introduced a new constant. That constant being absolute spacetime. Einstein also realized that you can divide absolute spacetime into "chunks" from many equally valid perspectives. This is due to the fact that when objects move relative to one another their way that they perceive spacetime falls out of sync with one another. Thus to different people events that occurred simultaneously would appear on different chunks of spacetime.  The concept just mentioned is known as the "relativity of simultaneity." It can be further simplified to "observes in relative motion do not agree on simultaneity-- they do not agree on what things happen at what time." His theory also provided a major point that all observers can agree on, that is that so long as your are moving straight through space time, you are not accelerating.Special relativity has one major weakness, that is that it does not account for gravity. Additionally Einstein realized that special relativity was in direct conflict with Newton's theory of universal gravitation, due to that statement  of the speed of light being that fastest that any object can go. According to Newton gravity  acts instantaneously and thus would move faster than the speed of light, making things a little bit difficult for Einstein. Einstein embarked on a quest to produce a new theory of gravity that would be as accurate as Newton's while conforming with special relativity. The key to Einstein forming the theory of general relativity was the realization that acceleration and gravity are the same, and using that equivalence he was able to apply the observation that accelerating observers view spacetime through curved/warped chunks to gravity, he then concluded that gravity is a warp or curve in the fabric of spacetime.