Physicists have invented a new way to shake a martini

Shaking a drink in a martini glass creates mesmerising patterns of small whirlpools.

Zhao Pan at the University of Waterloo, Canada, was travelling abroad when he ordered a drink in a bar and stumbled upon an intriguing physics discovery. His martini was full of bubbles, and because he was sitting by a window, he could clearly see them trace a complicated structure of vortices when he shook the glass back and forth.

Later, he repeated the process in the lab with …