Laser Barometer

This contraption is currently one of the most sensitive barometers on the planet earth... That is until YOU build one too! With a soup can, a balloon and a cheap laser pointer you can make a barometer that is so sensitive it's indicator will sweep across a scale of well over a meter down a short hallway. In fact it's so sensitive that even touching the can will make it swing the laser quickly upwards due to the heat of your hand! Aimed down a hallway you can see the weather outside change the re