What’s a Heron’s Fountain? It dates back to ancient Greece and it’s a great water science project for kids. Heron of Alexandria (ca 62 AD) was an inventor, mathematician and physicist who invented what looks like a magic trick. It’s fun and an opportunity for kids to learn about gravity, air compression and vacuums. A great end-of-summer project and, as we get ready to go back to school, a great science fair project.
How does the Heron’s Fountain work?
You know what gravity is, right? You would think that water draining from a top bottle into a bottom bottle would just flow down and stay put. This experiment defies that logic (which is why it seems like a magic trick.) Essentially, a Heron’s Fountain uses compressed air to lift water to a point higher than the origin. This action is the same thing that moves water in fish tank filters and some types of coffee percolators.
How do you make a Heron’s Fountain?
Connect two bottles together with a plastic tube (with strategically placed holes) in each bottle. We’ve got the Fountain Connection (made in USA!) which has done all the drilling for you. Fill one of the bottles with water. When you turn it over, gravity pulls the water from the upper bottle into the bottom bottle and compresses the air in the bottom bottle. As the water leaves the upper bottle, it decreases the air pressure of that bottle and causes a partial vacuum. Then water is forced from the lower bottle, up the fountain tube and into the upper bottle, taking the place of the draining water. Voila! A fountain!
What do you need?
- 2 clean, clear plastic 2-liter bottles. The labels and bottom plastic mount (if it’s on) should be removed so you can see better but just make sure you have a stable base. Hint: I’ve heard that you can easily remove the labels and plastic mount with a hair dryer.
- The Fountain Connection – this includes the clear plastic tubes that you’ll need to make the experiment work.
- Water (or experiment with different liquids!)
- Food coloring (optional)
(Note: you can make a fountain connector and find and cut tubing yourself. The cap requires precise drilling to make sure you have an airtight seal and the correct holes in the tubing.)
More Heron’s Fountain science experiments
- What happens if you add color (red erupting volcano anyone?)
- What about blending colors? Red in bottom, blue in top?
- What happens if you use fluids other than water?
- What happens if you vary the amount of fluid in the bottle?
- What if you change the length of the tubes? (If you do cut them down, don’t cut on the end with the holes!)
- Try the vacuum and compression experiments illustrated on the back of the Fountain Connection package.
Another fun activity is to create a swirling tornado with the Tornado Tube (also made in the USA). It also uses 2 plastic bottles. This is a fun, hands-on demonstration of vortex action (think, tornadoes, whirlpools, water spouts.)
What are your favorite experiments?