This is the natural disaster to worry about

- [Derek] What happens if I heat up this rubber band? When you heat materials like glass or plastic,

the atoms vibrate faster. They get slightly farther apart and this reduces intermolecular forces.

So the material gets weaker. Under tension, it stretches. But when I heat up this rubber band, the opposite happens.

It actually pulls more strongly. The rubber band contracts and the weight goes up.

So why does this happen? Well, rubber is unlike any other material.