Gravitational radiation

Gravitational radiation is a form of energy that is produced by certain gravitational interactions and has the ability to propagate as waves. These waves, known as gravitational waves, are ripples in the curvature of spacetime that are generated by accelerated masses and propagate as waves outward from their source at the speed of light.

Overview

Gravitational radiation is a key prediction of Albert Einstein's theory of general relativity. The theory, published in 1915, describes gravity not as a force, but as a consequence of the curvature of spacetime caused by mass and energy. When a mass accelerates, it can generate waves that propagate at the speed of light, carrying energy away from the system. This is similar to the way an accelerating electric charge generates electromagnetic radiation.

Detection

The first indirect evidence of the existence of gravitational waves came from the Hulse-Taylor binary, a system of two neutron stars orbiting each other. Observations of the system showed that the stars were gradually getting closer together, in line with the prediction of general relativity that the system should be losing energy through the emission of gravitational waves.

The first direct detection of gravitational waves was announced by the LIGO and VIRGO collaborations in 2016. The detected waves were generated by the collision of two black holes.

Effects

Gravitational radiation carries energy away from its source in the form of gravitational waves. This can have significant effects on systems that emit such radiation. For example, in binary systems, the loss of energy can cause the two objects to gradually spiral towards each other.

See also

• Gravitational wave astronomy
• Gravitational wave background
• Gravitational wave observatory