Physics
Interferometry
Quick fact
The Laser Interferometer Gravitational-Wave Observatory (LIGO) uses interferometry to detect ripples in spacetime as small as one-thousandth the diameter of a proton.
Why this is interesting
Have you ever noticed the shimmering colors on a soap bubble? That iridescence is a beautiful example of interference—and the same principle allows scientists to measure distances smaller than the width of an atom.