Fermilab Holometer
The Fermilab Holometer, based at Fermilab in Illinois was a laser interferometer intended to be the world's most sensitive, surpassing the sensitivity of the GEO600 and LIGO systems, and theoretically able to detect holographic fluctuations in spacetime. According to the director of the project, the Holometer should be capable of detecting fluctuations in light of a single attometer, meeting or exceeding the sensitivity required to detect the smallest units in the universe, called Planck units.