Make a non stop water fountain out of 3 plastic bottles and straws. This really cool self pouring liquid science trick is a great experiment to try at home. It’s a fun experiment that led to a lot of discussions about perpetual motion and free energy. My version does not exhibit either of these properties, but you may be able to fool people into thinking it does.
This is a really easy build and would be a perfect project for to build with your kids. Maybe you could even sneak in a lesson on fluid dynamics or perpetual motion.Heron’s fountain is not a perpetual motion machine.If the nozzle of the spout is narrow, it may play for several minutes, but it eventually comes to a stop. Watch the video from DaveHax for more info:
The water coming out of the tube may go higher than the level in any container, but the net flow of water is downward. If, however, the volumes of the air supply and fountain supply containers are designed to be much larger than the volume of the basin.
With the flow rate of water from the nozzle of the spout being held constant, the fountain could operate for a far greater time interval.As soon as the water level in the upper container has dropped so low that the water bearing tube no longer touches the water surface, the fountain stops.//wikipedia