Gravitational waves are disturbances or ripples in spacetime produced by the acceleration of massive objects, such as colliding black holes, merging neutron stars, or even the early universe’s rapid expansion. These waves were first predicted by Albert Einstein in 1916 as a consequence of his General Theory of Relativity.
According to general relativity, massive objects curve the fabric of spacetime. When such objects undergo rapid changes in motion—especially asymmetric acceleration—they generate waves that propagate outward at the speed of light, carrying energy away from the source. These waves stretch and compress space itself, though the effect is extremely tiny.
Gravitational waves were directly detected for the first time in 2015 by the LIGO (Laser Interferometer Gravitational-Wave Observatory) when it observed the merger of two black holes over a billion light-years away. This discovery opened a new era of astronomy, enabling scientists to observe cosmic events that are invisible to traditional telescopes.
These waves provide unique information about the most extreme environments in the universe, such as:
- Black hole mergers
- Neutron star collisions
- Early-universe dynamics
Gravitational wave astronomy complements electromagnetic observations, giving us a deeper and more complete understanding of the cosmos.