Parental Note: This experiment is geared towards ages 7 and up.
Additional Note: This experiment will take roughly 30 minutes to set up and complete. Adult assistance is required to boil water.
Air is all around us, and air pressure is the force exerted on a surface by the air above it due to gravity pulling it towards Earth. Pressure on Earth varies with altitude — the closer to Earth’s surface you are, the higher the air pressure, and the further up in the atmosphere you go, the lower the pressure becomes. The same is true in the ocean. The further down you go in the ocean, the greater the surrounding pressure from both the ocean water and the air above it becomes.
In this experiment, you will observe how differences in air pressure in a closed space can cause an object to collapse. The sudden collapsing of an object toward its center is called an implosion.
- Hot water
- Cold water
- Plastic bottle
- Glass baking dish
Remove the cap from the bottle and place the bottle standing upright in the baking dish and place the funnel inside the mouth of the bottle.
Ask an adult for assistance with this step. Bring some hot water to a boil. Using the funnel, carefully pour the hot water into the bottle.
Screw the cap back onto the bottle and lay the bottle on its side in the baking dish.
Pour the ice and cold water into the baking dish, surrounding the bottle. Roll the bottle around a bit in the ice water.
Stand the bottle upright again in the baking dish and observe what happens next.
Share Your Results:
What happened to the bottle after it was placed in the ice bath for a few moments? What do you think caused this to happen?
It is the difference in air pressure that caused the bottle to crush. As the warm air inside of the bottle cooled, it exerted less and less pressure on the walls of the bottle. Since the pressure outside of the bottle became greater than the pressure inside of the bottle, this created a vacuum, and eventually, the bottle began to get crushed. This happens because nature wants everything to be in balance, or in equilibrium. In order for the internal pressure of the bottle to be in equilibrium with the external pressure of the bottle, the bottle implodes. This is why underwater vessels such as submarines have what’s called a “maximum depth rating.” As the submarine travels deeper and deeper in the ocean, the pressure from the outside environment increases. If the outside pressure becomes greater than the pressure inside of the submarine, it could eventually crush the submarine.