It’s a big boom, only on a miniature scale. When waves build up in a quantum fluid of ultracold caesium atoms, they can cause the atoms to ripple outwards in a starburst shape, creating beautiful, tiny, fireworks.
The fireworks occur in a Bose-Einstein condensate, (BEC), a quantum gas made of particles called bosons cooled to near absolute zero. Caesium atoms are bosons, so Han Fu at the University of Chicago and her colleagues placed a highly cooled gas of these atoms in a disc-shaped trap formed by lasers, which held …