Over the years and in various experiments, however, researchers have generated entangled particles that have supported the theory. In these experiments, researchers first entangle two particles and then send them to different locations miles apart. The researchers then measure the state of one particle: for instance, the polarization (or direction of vibration) of a photon. If that entangled photon displays a horizontal polarization, then so too will its faithful partner.
John Preskill wrote a song about entanglement, and performed it with singer Gia Mora at One Entangled Evening, a 2016 IQIM event. Watch the video.