Field equations
Field equation of Einstein's General theory of relativity is perhaps one of the greatest theories ever discovered by any human intellect. It reveals a certain structure of the physical world, which has a great impact on philosophy and science. Gravity can be easily explained using the field equations as a curvature of spacetime. It is a tensor equation and so valid in any reference frame. Although the field equation is harder to solve, many exact solutions have been found over a century. Solutions of field equations gave many interesting facts about the universe like black holes, worm holes, and time travel. A worm hole is a hypothetical gateway that connects two distant regions of space. It can be used as a time machine also. In the movie Interstellar, the crew of the ship travel through a wormhole, which was shown to be a sphere in three dimensions.
