PITTSBURGH (KDKA) — Last time we showed you some interesting rubber band, or as we call it around here, “gum band” science where they heat up when you stretched.

This week we are going to find out what happens when you add heat to a stretched rubber band, and just to “let the cat out of the bag”, it is probably going to be the opposite of what you think!

To do this, we are going to attach a weight to a rubber band. Here we used a partially filled water bottle. We clamped the rubber band to our counter, and we want the rubber bands to stretch, but we also want it to remain suspended off the ground.

So we have reference points for this experiment, we drew some lines on a piece of old cardboard.

At this point, we use the hair dryer to heat up the rubber band.

Now, what do you think is going to happen?

Adding heat to the rubber band makes it shrink, causing our weight to lift! Many things expand when heated, but in the case of polymers, or chains of molecules, shrinking will occur.

Remember from last time, the polymers in rubber, when stretched, are like lines of chains.

When these chains of polymers are stretched and heated even more, they begin to vibrate. As these chains vibrate, they become shorter, causing the rubber bands to contract, or shrink. This lifts the water bottle!.

This is just another complex thing about a seemingly simple rubber band!