(New Scientist) Walking on water is possible – just as long as it contains corn starch. Now it seems this miracle mixture, dubbed oobleck, can also shatter like glass. Knowing how and why could help guide its use in soft body armour and car suspensions.
Oobleck gets its name from the artificial gloop that falls from the sky in the Dr Seuss book Bartholomew and the Oobleck. It has a split personality because the corn starch exists as a solid suspended in liquid water. Gently poke real-life oobleck and your fingers easily slip through, but slap it and it suddenly stiffens.
Along with ketchup and toothpaste, which jam up if you squeeze their containers hard, it is an example of a non-Newtonian fluid. “They can be solid if you make them flow too fast,” says Matthieu Roché of the University of Paris-South. Oobleck is the most extreme variety, capable of supporting a person running across a pool, though they will sink if they slow down.