- You can try it at home with a empty soda can).
- Fill it with a little amount of water.
- Heat it up, make sure to leave a hole in the container. Water will evaporate, replacing the air.
- After some time, seal the hole. Put it in cold water (you can put it in a bucket of water, head first - so you don't have to seal the hole). Water fumes will cool off, decrease in volume, the pressure inside the can will drop. Outside pressure will crush the can.