PhilK

** Theory of Relativity ** is a general theory of physics, made by Albert Einstein, which involves an analysis of time and space, leading to a general idea of physical laws, withimportant contributions to physics and in cosmology. Historically, the theory developed in two stages. Einstein's first one in 1905 (now known as the special, or restricted, theory of relativity) does not treat gravitation; and one of the two principles on which it is based, the principle of relativity (the other being the principle of the constancy of the speed of light), stipulates the form invariance of physical laws only for inertial reference systems. Both restrictions were removed by Einstein in his general theory of relativity developed in 1915, which shows equivalence between inertial and gravitational effects, and leads to a successful realistic example of Isaac Newton's theory of gravitation. Here's an example: Our common sense tells us that if while standing on a moving boat we hit a golf ball off the front, the speed of the barge adds to the speed of the golf ball. If we were to shine a flashlight in the same direction as we had hit the ball we would find that the speed of the barge does not add to the speed of the light beam. Its speed would be the same as if the barge were not moving at all. It's basically saying everything is affected when things move, the way i see it. Robert H. Wald, Ronald J. Adler, "Relativity", in AccessScience@McGraw-Hill, [|http://www.accessscience.com], DOI 10.1036/1097-8542.580100.
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What really facinates me and most people, is how the theory deals with time travel. For Example, If you got in a rocket ship and accelerated you could go what seems to you to be very fast. You could travel to a star 100 light years away and get they by lunch, turn around, and get back to Earth the same day. But you will find that everyone else is 200 years (and one day) older than you are. From their perspective, you were traveling very close to the speed of light and it take 200 years for light to get to that star and back. But to you, it was only a day. Your aging slowed down because you move forward through time faster. What you observe as speed in space that obeys Newton's laws, isn't what really happens. You start out accelerating in space but as you gain speed you start accelerating through time instead. You can only move at the speed of light in space, but can move infinitely fast through time. We have Einstein to thank for this theory.