At Year 7 Science Club, after School on Thursday this week, our students took on the challenge of making Cartesian Divers. This classic science experiment is named after René Descartes (1596-1650), a French scientist and mathematician who used the diver to demonstrate gas laws and buoyancy.

The students had to fill a bottle with water and drop in their ‘diver’- in this case our budding Scientists used pen lids. They discovered that squeezing the bottle caused the diver to sink because the increased pressure forces water up into it, compressing the air at the top. This increases the mass, and density, of the diver causing it to sink.

By releasing the squeeze, the students found that this decreases the pressure on the air at the top of diver, and the water is forced back out of it, lowering its density and allowing it to float back to the top of the bottle.

Year 7 had great fun testing out their divers and racing against each other, seeing who could create the most pressure to make their diver move faster.