Theory of Relativity


Throughout the course of life one stumbles on many questions about how things come to be and work. Asking questions is the simple part, analyzing them and formulating hypothesis/theories, is where the difficulty takes place. Many great minds of our past do this exactly, ask question, formulate theories, and perform experiments to test their theories. Great minds such as Bohr, Dalton, all the way down to Newton, have contributed to providing answers for some of our questions. Most of these minds were in fact physicists. However, of all these great and forever remembered names one stands out among the rest, The late, great, German born, Albert Einstein. Einstein's popularity comes from his Discovery of the, "Theory of Relativity". "The Special Theory" planted the roots of what was later developed to be "The General Theory". The General theory can be broken down into three assumptions, which were made by Albert Einstein.

Einstein's third major paper in 1905, on "Electrodynamics of Moving Bodies", contained what is now known as the, " Special Theory of Relativity". No explanation for the way radiation and matter interact when viewed from different inertial frames of references, that is an interaction viewed simultaneously by observers at rest and observers moving at uniform (constant) speed.

In 1905, after considering these problems for ten years, Einstein realized that the base of this problem lay not in a theory of matter but in theory of measurement. The heart of the theory of relativity lays in the realization that all measurements of time and space depend on Judgements as to whether two distant events occur simultaneously.

The general formula was created on a set of field equations, founded by Einstein in 1915. Einstein's idea was to regard the geometrization of gravity 4 dimensional, 3 dimensions for space, and 1 dimension for time. Each inertial system is given its own special time, our being seconds. Spatial co-ordinates and time have absolute characters/properties reasonable by stationary clocks and bodies depend on state of motion in inertial systems.

The special theory is based on two assumptions. The first assumption is: The laws of physics are the same in all inertial systems and no preferred system is preferred. This assumption became known as, "The Principle of Relativity". The second assumption is: The speed of light in space is the same in all-inertial systems. One consequence to the first assumption was that on e cannot detect whether an inertial system is, from within, at rest or is moving in a constant velocity.

A draw back of the special theory is that in principle it does not apply to matter which is in motion/accelerated, there would be no problem if the matter was under strong gravitational field much stronger than the one here on earth. In order to take acceleration in account Einstein made another assumption.

His final assumption was that the laws of physics in an inertial system in which there is a uniform (constant) gravitational field are the same as in a uniformly accelerated system in which there is no gravitational field. This assumption became known as, " The Principle of Equivalence".

Later Einstein proposed that the "Special Theory" along with "The Principle of Equivalence" also apply to non-uniform gravitational fields (Field with changing gravitational forces). Thus, the General Theory of Relativity was born.

Non uniform fields are hard to handle mathematically. By means of various mathematical transformation laws of fields can be imitated by less complex fields. Through metric geometry and gravitation, can be linked, so that the gravitational field corresponds to curvature of space-time. The presence of matter causes space-time to warp in a region near it. In some sense matter is absent in General relativity the role is taken over by curvature.

No new theory will ever gain any acceptance in the scientific communities unless it is able to make predictions that can be tested. The testable prediction of General Relativity are rather limited in number but have had crucial impact on our understanding of the cosmos - prediction and discovery of the gravitational redshift, prediction and discovery of the deflection of light in the gravitational fields and time dilatation in gravitational fields have changed the outlook of humanity completely with the assistance of Albert Einstein and his "Theory of Relativity".

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