Many children have tried to make a Cartesian diver with a pipette in a bottle of water, but it can be a little difficult to find the right amount of air in the pipette so that it works. We will show an easier way to do it, with lemon or orange peel.
- A jam jar
- A balloon
- Rubber band
- Peel from an orange or a lemon
- Cut the peel like a submarine and place it in a jar with water
- Thread the balloon over the opening on the glass, and secure the balloon with a rubber band
- Press the balloon
When you press the balloon, you see that the peel sinks. This is because the pressure increases in the water, and then the air bubbles inside the peel are pressed together, making the shell becomes heavier and sinks. Similarly, when you release the pressure, the peel rises again.