Cartesian Jellyfish: increasing pressure in the water compresses air bubbles inside the plastic capsules, filling them further with water making them sink in this cute version of the famous Cartesian Diver toy. In this whimsical version the jellyfish also spin when the pressure is released as the water is channeled out of the capsule/head in a sideways jet. Pascal’s principle states that any change in pressure on an enclosed fluid (such as squeezing the plastic bottle) is transmitted evenly to e