What’s happen?
Squidy is made up of the eye-dropper, the bubble of air inside the eye-dropper and the small amount of water in the eye-dropper. It is the bubble of air that gives Squidy its buoyancy and makes it float. When the bottle is squeezed, the increase in pressure causes the air bubble inside Squidy to be compressed and get smaller. This allows more water to enter the eye-dropper which makes Squidy denser and it sinks. When the sides of the bottle are released the pressure acting on the air bubble inside Squidy reduces and the air bubble expands. As the air bubble gets bigger it pushes some water out of the eye-dropper. This makes Squidy less dense so it floats to the top of the bottle.
DID YOU KNOW?
Squidy works in a similar manner to how a submarine dives and rises. Submarines have ballast tanks that can be filled with water to increase the overall weight of the submarine to make it sink. A submarine rises to the surface when compressed air is released into the ballast tanks. This pushes the water out of the tanks which decreases the weight of the submarine, making it more buoyant.