 I have an empty glass bottle with me, with a balloon attached at the top and I have a container of really hot water. I will place this bottle into this hot water and I want you to predict what will happen. Will you see anything happening to the balloon? Take a prediction. Alright, let's see. Well, it seems that the balloon is inflating. Wow, that is amazing. Look at that. The balloon has almost inflated entirely. That is pretty awesome. But why did it happen? Can you think of an explanation?