You Too Can Walk on Water

Everyone has seen this video by now haven’t they? Well, I hadn’t until very recently and because it’s got a science type theme I just had to share it. Thixotropic materials make walking on “water” quite possible, but don’t stand still for too long.

The pool is actually filled with a solution of cornstarch (cornflour in the UK) and behaves very much like a liquid when you try to stir or disturb it slowly, but apply a force more quickly (such as running across a big tub of it) and it behaves more like a solid. Such thixotropic, or non-newtonian fluid behavior is essentially down to the way the molecules comprising the mixture can move relative to each other.

There’s a nice experiment you can do at home here, unless you’ve got a tub as big as the one the “experimenters” in the video used!