Cartesian Diver Toy

Make your own Cartesian Diver Toy! Fill a 2 liter bottle to the top with water, drop the diver in and close lid tightly.He will float at the top.Squeeze the bottle (very hard, you might have to help your little one… I leaned into making it more buoyant than normal to combat the plastic absorbing lots of water) and hold it for a moment, the diver will drop to the bottom.Release your grip and he will shoot back up to the top.Repeat until your hand gets tired! A little explanation of what is happening (courtesy of ChatGPT because my hand is sore from all the failed prototypes….) The physics behind a Cartesian Diver revolves around these key concepts:Buoyancy:An object will float if its weight is less than the weight of the fluid it displaces.This is governed by Archimedes' Principle.Density:Density is mass per unit volume.Objects with lower density than the surrounding fluid float.Objects with higher density sink.Pressure:Pressure is force per unit area.In a fluid, pressure increases