Physics behind freezing bubbles’ hypnotic ice crystal dance revealed
Marangoni flow responsible for the often photographed but never studied snow globe effect in freezing soap bubbles
Scientists have uncovered the physical effect that turns freezing soap bubbles into tiny snow globes. When temperatures reach far below soapy water’s freezing point, –6.5°C, bubbles freeze in a dizzying display of swirling ice crystals. Unlike in bulk water, there is no single freezing front. As ice crystals form where the bubble touches the cold surface, they quickly move upwards, dancing wildly around the surface before slowing down and merging into a solid ice layer.