What is interferometers?

Interferometers are instruments that use the interference of waves (typically light, radio waves, or sound waves) to make precise measurements. They work by splitting a wave into two or more paths, then recombining them. The interference pattern created reveals information about the differences in path length or refractive index, which can then be used to measure distances, displacements, refractive index changes, and other physical phenomena with high precision. They are commonly used in astronomy (to measure the size and distance of stars), metrology (for precise length measurements), and other scientific and engineering applications.