Apropos of Nothing

Silly Putty, like custard, is a dilatant; both are materials that are viscous liquids when under little pressure (or more accurately, shear forces). When placed under pressure (like, jumping in a thin layer of custard, or throwing a ball of silly putty against a wall), they "tighten." Silly putty and custard, to put it simply, are liquids at rest, and solids when stressed.

Hey, neat, that rhymes.

What this means for Silly Putty afficionados is that you can't build sculptures out of the stuff. You try, and it basically flows down under the force of gravity and becomes a pile of really unattractive pink goo. If you try to freeze the sculpture, it will puddle before it gets cold enough to solidify, and you'll have an unattractive puddle of very cold pink goo. If you try to bake it, it will catch fire and kill you and your family.

But here's the interesting part, and I just discovered this today while playing with some Silly Putty and a can of compressed air (for cleaning keyboards...the air, not the rubbery goop): Silly putty holds an open "vacuole" when wrapped around an air bubble.

When you push compressed air into the Silly Putty, it expands it. In theory, this should weaken the structure. However, for reasons unbeknownst to me, the damn stuff is holding the bubble inside and not losing volume. Admittedly, it's still flattening out. And it's still some unattractive pink goo. But it seems that as long as the stuff's integrity remains, it will hold that bubble. And even better, it looks like it's holding it longer than a standard blob of silly putty would hold up.

I imagine that I'm the only one who finds this interesting.