Have you ever attempted to empty a full container of liquid? As autumn arrives, you may have an outdoor swimming pool filling with leaves, and now is the time to prepare for winter and empty your swimming pool.
Instead of relying on buckets to empty your pool if you don’t have a drain, simply use a siphon!
The History of the Siphon
The origin of the siphon can be traced back to the ancient Egyptians, who used siphons for their innovative irrigation systems as well as many other farming tools we recognise and use today.
Siphons were used to move water from canals and rivers to irrigation channels for crop production. Cotton farmers today still use similar siphons to irrigate crops.
Ancient Egyptians also used siphons for winemaking with a similar process that is still used. Siphons assisted the transfer of wine from large containers to smaller vessels. The hoses were placed inside the container. This simultaneously improved the wine’s purity by filtering particles at the bottom and top of the container.
Simply place one end into the pool with the other outside, ensuring that this end is below the water level and within an area the water can drain into.
You can use a small-scale pump, or even your mouth, to suck the water up through the hose. This gets the flow of water started.
Once the siphon starts to work, it will carry on draining water until there is no more or the end of the rubber hose is moved above the level of water. Either of these actions will stop the siphon.
The Science Behind the Siphon
Despite their being used for centuries, modern scientists are uncertain which exact forces and principles make the siphon work.
Most scientists believed siphons worked due to atmospheric pressure. However, when tested within a vacuum, the siphon still worked. This means there must be other forces at work, as atmospheric pressure requires air.
More recently, scientists have theorised that the likely major force at work is gravity. When the liquid is sucked through the tube, gravity continues to push the liquid through with the help of cohesive bonds within the liquid.