Liquid droplets splashing against a surface are actually bouncing off a tiny cushion of air (Image: Joe Pepler / Rex Features)
WHEN does a raindrop splash? Surprisingly, the process begins before it makes contact.
A liquid drop hitting a surface often flattens into a thin sheet that then bounces to form a crown shape. Previous experiments have suggested the surrounding air plays a role: a droplet doesn’t splash so easily when the air pressure is low, instead spreading out into a thin pancake.
Shreyas Mandre of Harvard University and colleagues ran computer simulations of liquid drops hitting a solid…
