Gravity

Gravity is a physical phenomenon as an attraction between two bodies possessing mass. This includes all the celestial bodies to the subatomic particles. Any object with mass and energy is influenced by gravity. Gravity is what that causes the tidal waves, the moons to be tidally locked, the Earth to withhold all the life and structures, the starts to form clusters and so on. The common misconception in physics about gravity is that it is regarded as a force. Gravitational Force is one of the fundamental forces of nature, but it is a phenomenon.

Gravitational force is long range and the weakest of all fundamental forces. It gets weaker if the distance between objects increases. Gravity is approximately 1040 times weaker than The Strong force, which is the strongest fundamental force in nature. Gravity is more prevailing in macroscopic level while other fundamental forces play an important role in more smaller scale. Sir Isaac Newton, in the year 1687, stated the inverse square law of gravitation. It says that the gravitational force between two or more objects is directly proportional to the product of masses of the objects and inversely proportional to the square of the distance between them, where G is the universal gravitational constant. This formula and theorem describe the effects of non-relativistic gravity in classical mechanics, that is it works for bodies that travel with speeds much lesser than the speed of light.

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The equivalence principle had a few chains of experiments to demonstrate that all objects fall at the same rate when opposing forces such as friction, air resistance, drag, etc are removed. It was to check if effects of gravity were indistinguishable with certain aspects of positive and negative acceleration. When bodies of unequal masses are dropped from a certain height in resistance free space like the vacuum, they fall at same rate and acceleration, that is the acceleration due to gravity, g= 9.8 ms^-2.

The weak equivalence principle by Lorand Eötvös, states that the trajectory of a mass in the gravitational field only depends on its initial velocity and position and independent of its composition. Einstein also stated that any non-gravitational experiment in free fall is independent of the velocity of the constitution and its location in space-time. Albert Einstein says that gravity is a result of Quantum mechanics and general relativity. It may not have any significance in subatomic level for now but he proposed that this could be a key to the standard model's last unfinished piece. It was theorized that gravity might arise through exchanged of virtual particle called gravitons, the same way Electromagnetic forces arise due to the exchange of Photons. He also said that Gravity is a consequence of warps, disturbances, and curve of space-time, as distorted by bodies with mass. The twin neutron stars that rotate around each other so fast that they warp space-time fabric producing gravitational waves. The black hole tears a hole through space-time curvature deep into a singularity, where nothing can escape from its gravitational pull. Any object goes beyond its event horizon is lost for good.

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Einstein's last work was to unify all the fundamental forces, The unified field theory. He tried to unify the fundamental forces and elementary particles and write them in terms of Physical and Virtual fields. Unifying gravity to Grand unification theory would result in The theory of everything (ToE). This would explain all the physical aspects of the universe and its theoretical frameworks. In general relativity, the effects of gravity are prescribed by the curvature of space-time. In an inertial frame of reference, the effects of gravity are stated by classical mechanics. In the non-inertial frame of reference, the free-falling objects take a straight path in space-time called geodesics. They are said to be inertial in space-time in other frames of reference. For radial distances greater than Schwarzschild Radius of a celestial body, the accelerations prescribed for it is identical to Newton's gravitational theory. The earliest peak of gravity was most possibly in form of quantum gravity or gravitational singularity which came into being about 10^-43 seconds after the birth of the Cosmos. It can exist as being as theorized by Zero-point field (Quantum state with the lowest energy), virtual particle (Identical to an ordinary particle to which some of the characteristics are limited by uncertainty principle), etc.

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The unification of theory of gravity with The theory of everything would allow the explanation of anomalies and discrepancies in the universe like extra fast stars; energetic photons; massive hydrogen clouds, accelerated the expansion of Cosmos.