Gravitational waves are ripples in the fabric of space-time, caused by the acceleration of massive objects. They were predicted by Albert Einstein's theory of general relativity and were first observed in 2015.
Gravitational waves are fundamentally different from electromagnetic waves because they are caused by the acceleration of masses, while electromagnetic waves are caused by the acceleration of electrically charged particles. Additionally, gravitational waves can pass through any type of matter, while electromagnetic waves can be absorbed or reflected by certain materials.
When a gravitational wave passes through matter, it causes the matter to stretch and compress in a cyclical pattern. This stretching and compressing is known as strain, and it is the main way that scientists detect gravitational waves.
While gravitational waves do have an effect on matter, it is usually too small to be noticeable on Earth. However, extremely powerful and close gravitational waves, such as those from a black hole merger, could potentially cause a measurable distortion in space and time.
Scientists use highly sensitive detectors called interferometers to detect gravitational waves. These detectors measure the slight changes in distance caused by a passing gravitational wave and convert it into a detectable signal. This signal is then analyzed by scientists to confirm the presence of a gravitational wave.