Gravitational waves are ripples in spacetime caused by some of the most violent and energetic processes in the Universe. Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity. Einstein's mathematics showed that massive accelerating objects (such as neutron stars or black holes orbiting each other) would disrupt space-time in such a way that 'waves' of distorted space would radiate from the source (like the movement of waves away from a stone thrown into a pond).
Predicted by Albert Einstein in 1916 as part of his Theory of General Relativity. For decades, they were only a theoretical concept because the effects were thought to be too small to detect. Indirect evidence was found in 1974 by observing a binary pulsar system. The first direct observation was made on September 14, 2015, by the LIGO and Virgo collaborations, resulting from the merger of two black holes.
The detection of gravitational waves opened a new window into the cosmos, allowing astronomers to observe the universe in a way not possible with electromagnetic waves (light). This new field, 'multimessenger astronomy', combines gravitational wave data with light from telescopes to study cosmic events. It has confirmed the existence of binary black hole mergers and provided new insights into the nature of gravity, neutron stars, and the expansion of the universe.