Gravitational waves are disturbances in spacetime caused by the acceleration of massive objects. They are predicted by Einstein's theory of general relativity and were first detected in 2015.

Albert Einstein predicted the existence of gravitational waves in 1915 as a consequence of his theory of general relativity.

Gravitational waves travel at the speed of light, which is approximately 299,792,458 meters per second.

The LIGO experiment (Laser Interferometer Gravitational-Wave Observatory) is a large-scale interferometer used to detect gravitational waves. It consists of two L-shaped interferometers, one in Hanford, Washington, and the other in Livingston, Louisiana.

Gravitational waves were first detected on September 14, 2015, by the LIGO experiment.

The first detected gravitational waves were produced by the collision of two black holes, which occurred approximately 1.3 billion light-years away from Earth.

The first detection of gravitational waves was a major scientific breakthrough. It confirmed the existence of gravitational waves, opened up a new window on the universe, and allowed us to study the properties of black holes.

Gravitational waves have a wide range of potential applications, including studying the early universe, detecting black holes and neutron stars, and measuring the properties of dark matter and dark energy.

The theory of relativity is a theory that explains the relationship between space, time, and gravity. It was developed by Albert Einstein in the early 20th century.

The two main types of relativity are general relativity and special relativity. General relativity is a theory of gravity that explains the relationship between space, time, and gravity. Special relativity is a theory of motion that explains the behavior of objects moving at very high speeds.

The principle of equivalence is the principle that all objects fall at the same rate in a gravitational field. This principle is one of the cornerstones of general relativity.

The Schwarzschild radius is the radius of a black hole. It is the radius at which the gravitational pull of a black hole becomes so strong that nothing, not even light, can escape.

The event horizon of a black hole is the boundary around a black hole from which nothing, not even light, can escape. It is the point of no return.

The singularity at the center of a black hole is a point of infinite density and gravity. It is a region of spacetime where the laws of physics break down.

The cosmic microwave background radiation is the leftover radiation from the Big Bang. It is a faint glow of radiation that fills the entire universe.