THE CARTESIAN DIVER

new twist for the great classic
Cartesian divers were first noted by a student of Galileo Galilee! Some people back in those days thought its mysterious dives and accents in the water smacked of dark magic, as witnessed by the name it was sometimes called: Devil's Diver. The advent of clear plastic bottles made Cartesian divers popular in school science classes, as well they should be. What a cool way to learn about density, buoyancy, compression of gases, etc.
Unfortunately, some diver designs are either too expensive for large groups, or they hide what's going on inside the diver. For example, pen caps and modeling clay are cheap enough for everyone to make, but you can't see the air compressing and the water rushing in. Using clear or translucent eye droppers costs at least a dollar each. Not bad if you're just making one at home, but quite a bit of money if you are making them with a large group. I offer two designs to fill the void. If my design is not what you are looking for