For many years time travel was the stuff of science fiction. This was all just part of the world's imagination until recently. Scientists now believe that the current laws of physics allow us to travel though time. They believe that we can now travel back to see our founding fathers sign the declaration of independence. We could travel to 2999 to witness the birth of the next new millennium. Such travel would require a machine capable of withstanding great pressures and incredible amounts of speed. The act of actually traveling though time is for the most part, agreed upon, but the implications of such travel is not so decided upon. Many different theorists have different views of what could happen and some go, as far as to say that if we did travel to the past, we would end up in a different universe that is a replica of this one. One of the most basic concepts is that of Dilation, a stretching of something. Some scientists believe that the main gateway to the past or future is a wormhole. Einstein's general relativity theory explains about universal constants, this is important to understand the concepts of travel at light speed. Traveling to the past could create problems if someone tried to change something. This is a paradox. A few of these paradoxes are explained through the use of quantum mechanics. Sailing though the cosmos at the speed of light with no time passing us by, moving throughout time to witness the ancient Egyptians create their masterpieces. This is an exciting concept that we could actually formulate and make happen. .
Before the time of Einstein, Newton and other great investigators thought of space as an infinite expanse in which all things exist (Hewitt 213). We are in space and we live in it along with all of the planets and stars. It was never clear if the universe exists in space or space exists in the universe. Dose space exists outside the universe or only within the bounds of it.