Saturday, 20 July 2013

Quantum Gravity


General Relativity accounted for the definition of this universe. It stated the model structure of the universe, its development and eventual fate. It predicts that the Universe must either be expanding or contracting. Before the introduction of General Relativity, space and time were thought of only an arena in which events took place. After General Relativity, physicists realized that space and time are dynamic entities that can be affected by mass, force and energy.


However General Relativity has its own limits. General Relativity was not able to explain the cause of Space Time distortion by mass. Many Physicists have not yet accepted the General Relativity completely rather they still stick to Newtonian Gravity which defines Gravity as a fundamental force. In fact Gravity is still defined by Newton's law. General Relativity too cannot explain the sub atomic particles too. Many scientist believe that it is Graviton (a bosonic particle) present in all bodies responsible for Gravity.

The subatomic world of science is primarily goverened by Quantum mechanics. One of the major goal of Modern Physics is to unify all theories of Gravity to build up Quantum Gravity. Quantum gravity takes with it Newtonian Gravity, General Realtivity and Gravitons and other two to three theories under it. It also accounts for the cause of forces in fundamental particles. Also Planck's Quantum theory is also taken into account.

A theory of quantum gravity which is also a grand unification of all known interactions, is sometimes referred to as a theory of everything (TOE) or a unified field theory (UFT). There is a great hope for solutions to all the problems in String Theory. Although some quantum gravity theories such as string theory and other unified field theories (or 'theories of everything') try to unify gravity with the other fundamental forces, others such as loop quantum gravity make no such attempt; instead, they make an effort to quantize the gravitational field while it is kept separate from the other forces.

All these theories are the solution to the modern physics. Several scientist have been involved in finding solutions from the last 50 years. If any of this theory is proved then there would be great scope of Physics in future.



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