The following posts have no fixed theme or style, but I hope you enjoy reading them!

Tuesday, 27 March 2007

Silly Putty

I bought silly putty today from a shop that was about to close down, so I thought I would tell you about it. It's pretty cool stuff

Like other polymers, it's made of long chains of atoms. These chains are linked together a little bit, but the main force holding it together is that the chains are all tangled up. So if you stick some sticky putty covering a hole, it will gradually drip through, as the chains untangle themselves (in GCSE science you learn that atoms are always vibrating - the chains actually shake themselves free of their neighbours)
But if you pull them really quickly apart with your hands, they can't untangle that quickly, so the only way they can react is to snap. Anytime you do things quickly, it will react like a solid, but if you do it slowly it is like a liquid. So it bounces and it flows, if you pull it slowly it stretches, or quickly it snaps. Yay so much fun

No comments: