Quantum physics: Bubbles give off weird light when popped and now we know why

Sonoluminescence, in which small bubbles in a liquid produce flashes of light when they collapse, is now known to be a quantum process

By Alex Wilkins

When a bubble pops in a liquid, it can produce a flash of light, which we now know is thanks to quantum mechanics.

Sonoluminescence is a phenomenon in which small bubbles, produced and fixed in place by an ultrasound wave in a liquid, collapse and make particles of light, or photons. Physicists have known about this process for decades, but the mechanisms behind it weren’t fully known.

Now, Ebrahim Karimi at the University of Ottawa, Canada, …