The well-known theoretical physicist, Albert Einstein has been widely acknowledged for developing the Theory of Relativity. Although, there has been a lot of controversy surrounding the validity of his experiments that prove the theorizing of time-space by gravity caused by massive objects.

So, what is the theory of general relativity?

Albert Einstein had provided that General relativity is generally the same idea as gravity, a force that keeps the planets in orbit around the sun, and a force that pulls everything to the ground. The reason why gravity keeps the planets in orbit at an angle is because space is curved, and gravity is caused by that curvature in space-time. Space-time is formed by space and time, making it a single geometry that states that space-time is a pseudo-Riemannian manifold, which in simpler terms, indicates that curved spacet-ime is locally flat and matter in curved spacetime obey Newton’s laws of motion.

Now, let’s imagine that you are sitting in a stationary train, and the train next to the one you are in, begins to move. It might seem as though you are in motion, and not the train next to you. This is an instance of relative motion. For this example of relative motion, it is necessary to understand that the speed of light (c) is constant for any frame of reference (coordinates that determine the position of the object in that particular frame) because each observer’s motion is relative to each other, the speed of light will then be measured the same. Therefore, we can acknowledge that “the faster you travel to the speed of light, time will slow down and the distance decreases”. So if we were able to travel as fast as the speed of light, we’ll notice that time slows down because the amount of time passed is small.

It is controversial as it questions the validity of this theory because the general relativity theory is an approximation, it is only applicable to certain situations which are that the energy momentum tensor (both energy & matter) and pseudo-Riemannian manifold (spacetime) obey Einstein’s field equations. The limitation of the theory of general relativity that makes it unable to inculcate the principles of quantum mechanics after the formulation of Einstein’s theories is because for the theory of general relativity, it focuses on how the events match up to the local effect. On the other hand, in quantum mechanics the events are produced by the interaction of subatomic particles. Hence, in quantum mechanics there is no definite outcome, it is subject to chance variation. Particles have some quantum properties which obeys the uncertainty principle allowing them to be at two places at the same time. For instance, if an electron travels through two slits it raises the question of which direction will the gravitational pull be. Even though gravity is about the curvature of spacetime, it needs to include the theory of quantum properties of time and space. Furthermore, general relativity doesn’t model the foundation of the Euclidean space and time model (Combination of euclidean space and time in a 4D manifold hence it is a spacetime interval where 2 independent events based upon where they are recorded. The general Euclidean concept is that it is the measure of the distance between 2 points of space) pervaded by energy bearing unchanging point charges.

A test done to verify the theory of general relativity was done by the scientists of RIKEN (Institute of Physical and Chemical Research) where they had utilized curvature of spacetime by gravity. This transportable optical lattice clock can be a precise test of the theory of relativity as it can allow the measure of ground swelling in active volcanoes, crustal deformation to define the height reference.

Overall, the theory is universally successful as the mathematical relationships and theories have been proven and tested to understand an alternative model of gravity under some circumstances reiterating the mention of parameters of the theory’s validity.

References:

“An Atomic Clock Measured How General Relativity Warps Time Across A Millimeter”. Science News, 2021, https://www.sciencenews.org/article/atomic-clock-general-relativity-time-warp-millimeter-physics. Accessed 12 Mar 2022.

RIKEN. “Testing Einstein’s theory of general relativity.” ScienceDaily. ScienceDaily, 9 April 2020. .

Will, Clifford M. “Gravitational Radiation And The Validity Of General Relativity”. Physics Today, vol 52, no. 10, 1999, pp. 38-43. AIP Publishing, doi:10.1063/1.882860. Accessed 13 Mar 2022.

Image: S3.Amazonaws.Com, 2022, https://s3.amazonaws.com/cms.ipressroom.com/173/files/20196/5d35ff9a2cfac239e9942675_Andrea+Ghez+art+1+final+by+Nicolle+Fuller+2019/Andrea+Ghez+art+1+final+by+Nicolle+Fuller+2019_cf3ee8d8-f673-41d7-ac3e-8b26c29e7a8e-prv.jpg. Accessed 13 Mar 2022.

“Relativity V Quantum Mechanics – The Battle For The Universe”. The Guardian, 2015, https://www.theguardian.com/news/2015/nov/04/relativity-quantum-mechanics-universe-physicists. Accessed 17 Mar 2022.

Elegio.It, 2022, http://www.elegio.it/mc2/LandauLifshitz_TheClassicalTheoryOfFields_text.pdf. Accessed 17 Mar 2022.