Gravitational wave detection involves measuring ripples in spacetime caused by massive cosmic events, such as the collision of two black holes or neutron stars. These waves travel at the speed of light and can stretch and compress space as they pass through it. Instruments like the Laser Interferometer Gravitational-Wave Observatory (LIGO) use laser beams to detect these tiny changes in distance caused by gravitational waves. By analyzing the data collected, scientists can learn more about the universe's most violent events and test predictions made by Albert Einstein's theory of general relativity.