Ultra-cold liquid helium

If you're squeamish, you may not want to listen to the strange whistle of ultra-cold liquid helium-3 that changes volume relative to the North Pole and Earth's rotation. When ultra-cold liquid helium-4 was squashed through an array of tiny apertures, a phenomenon occurred in which the helium-4 repeatedly sped up, slowed down and vibrated. This produced a "quantum whistle" -- a whistling sound that went from high to low.

Part of the Space is the Place project - for more information, see http://www.citiesandmemory.com/space

Recording by the European Space Agency.