Cartesian Diver

This week we did an experiment that went with our Apologia science. It showed the way a nautilus and an octopus would move in the water. Submarines also use this to move up and down in the water. First, we took a small water bottle and filled it to the top. Then we took a water dropper and filled it as full as we could and it still float in a cup of water. Then we put the dropper in the bottle and closed the lid tightly. When we squeezed the bottle the dropper(diver, nautilus, sub..) sank to the bottom of the bottom.

Dropper at the top.

Squeeze. It is sinking.

All the way at the bottom.

This is because when you put pressure on the bottle, you also put pressure on the water inside and the dropper fills with more water making it heavier and it sinks. When we let go of the bottle the water came out of the dropper and it floated. Pretty cool.

Usually you see this experiment labeled as a Cartesian diver. It was pretty simple to do and the kids loved it. Apologia is great!