In 2016, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected space-time ripples after two black holes collided about 1.4 billion light-years from Earth. These space-time ripples are known as gravitational waves. LIGO first detected gravitational waves in 2015; 100 years after Einstein predicted their existence. The waves are a part of Einstein’s theory of general relativity.
The matter of Mercury’s orbit has been discussed earlier. It was general relativity which showed how Mercury’s motions were affected by the curvature of space-time. It is even possible for Mercury to be cast out of our solar system due to these changes after billions of years.
Gravitational Lensing is the phenomenon by which a massive object (like a galaxy cluster or a black hole) bends light around it. When astronomers observe that region through a telescope, they can see the objects directly behind the massive object, due to the light being bent. A commonly given example for this is Einstein’s Cross, a quasar in the constellation Pegasus. The light of the quasar was bent by a galaxy nearly 400 million light-years away in such a way that the former appears four times around the galaxy.
The first ever images of a black hole were shown by the Event Horizon telescope in April 2019. The photos once again gave confirmation of several facets of general relativity. It not only showed that black holes exist, but also the existence of a circular event horizon. This is a point at which nothing, including light, can escape.
Picture Credit : Google