In this simple presentation, we see how siphons work. I asked Alex and Max to pay attention and tell me at what level should be water so that it starts going through the straw. So they did, had fun and learned something new. A siphon can lift the water up without a pump, and that is the reason it has been used for thousands of years. But even today it is not 100% clear why it works. Perhaps the challenge is there because a few processes are happening at the same time for siphons to work. On the one hand, air pressure pushes down on the water, so that it stays in a glass and cannot get anywhere else, but once we give it a way out, it takes it and goes through a straw. On the other hand, when a straw is filled with water, the lower part of the siphon weights more than the upper part. So like with scales, the force of gravity pulls the heavy side down taking the water through the tube. This process relies on the property of water to stick to itself, creating an unbroken chain of drops.