Pouring hot water through a long pipe, and allowing the pipe to expand and knock over a pingpong ball set at one end of the pipe.

Two sections of PVC pipes, ping pong ball, two stands, water kettle/hot water, books for levelling the pipes, bucket

Two sections of PVC pipe loosely held to 2×4's, push the two pieces together with a connector in the middle. There are two elbows at the ends of the joined pipe to pour hot water from one end and allow it to drain from the other into a bucket. A pingpong ball is set up at the draining end so when the pipe expands it knocks over the pingpong ball. With the use of the IR camera (optional), students can see the pipe lighting up.

The pipes are located over the red closet. Use books and stands to level the pipes over the lectern and the table in the lecture hall.