Strobe light

A strobe light is a device which produces regular pulses of bright light without the long period of decay in intensity at the end of a pulse, such as happens with ordinary incandescent light bulbs. It can cause a motion to seem to slow down due to aliasing. It was invented by Harold Edgerton.

They are common in nightclubs and at dance parties , although their use is limited because they can trigger epileptic seizures in susceptible people.