THE cartoon character SpongeBob SquarePants is renowned for his ability to blow bubbles in the shape of everything from squid to sausages. But for us, the physics of surface tension ensures that such feats are usually impossible.
Bubbles are spherical because this shape contains the maximum volume within the minimum surface area. For the same reason, the double bubble formed when two similar-sized bubbles touch usually combines into a bigger bubble, as this cuts the surface area by about 20 per cent.
But when the surfaces of the original bubbles are studded with polystyrene or zirconium beads around 3 micometres…
