(March 20, 2018)

Gravitational waves, which Albert Einstein predicted in 1916.2 were a riddle until 14 September 2015. Gravitational waves are small deformations of the four dimensional space–time geometry. They propagate with the speed of light and they are generated by catastrophic events in the Universe, in which strong gravitational fields and sudden acceleration (or deceleration) of asymmetric distribution of large masses are involved. In the other words, according to the theory of relativity, any accelerating or decelerating massive object that isn’t spherically or cylindrically symmetrical generates detectable gravitational waves. That object could be for example neutron star or black hole binary system. Gravitational waves are also produced by cosmological explosions such as supernova. Gravity is the weakest of the four fundamental forces, it is known for a very long time, but still there is no a good unique gravity force (field) theory.