Gravity, as we know it, is a force of attraction that exists between any two masses, any two bodies, any two particles. Gravity is not just the attraction between objects and the Earth. It is an attraction that exists between all objects, everywhere in the universe.
Newton’s law of universal gravitation states that every mass attracts every other mass in the universe, and the gravitational force between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them.
On the other hand, according to Albert Einstein, Gravity is not a force but just a property of spacetime.
Einstein’s theory of relativity defines Gravity as a consequence of the curvature of spacetime caused by the uneven distribution of mass.
Einstein’s general theory of relativity correctly describes the behavior of gravity over close to 30 orders of magnitude, from sub-millimeter scales all the way up to cosmological distances. No other force of nature has been described with such precision and over such a variety of scales.
The problem with Gravity is that it’s not like other known forces of the Universe.
If you try testing Gravity and happen to push it beyond a certain point, it collapses into a Blackhole.
And Blackholes are one of the 2 places where Einstein’s theory of relativity completely breaks down.
But if we are able to create a working quantum theory of gravity, it would change things in more ways than we can imagine.
And to that, it comes down to two theories:
String Theory and Loop Quantum Gravity.
String Theory is the most acceptable theory. Loop Quantum Gravity is just… ‘wrong‘.
P.S. So interesting yet so annoying!