Do Not Open this Bottle – The Ultimate Science Prank

Don’t bring your new neighbors a bottle of wine as a house warming gift. You are more creative, fun and love pranks. This ultimate prank uses the simplest of props… a plastic soda bottle filled with water. Even though the words “DO NOT OPEN” are printed on the bottle, people just can’t resist the temptation.

To make your own leaky bottle, you just need an empty plastic soda bottle, Sharpie pen, push pins and water. Fill the plastic bottle with water (make sure you screw the cap on tight). Write “DO NOT OPEN” on the outside. Use your push pin to poke little holes around the lower half of the bottle. Then head on over to the neighbor’s house.

They will not be able to resist opening the bottle. When they do, a nice little sprinkler spray of water will welcome them with open arms. To stop the spray, tighten the lid.

How does this work? The simple answer is air pressure. Before you fill it with water, the bottle is filled with air molecules. When you pour water into the bottle, the molecules of air that once occupied the bottle come rushing out of the top. You don’t notice this because molecules of air are invisible. When you turn a bottle filled with water upside down, the water pours out (thanks to gravity) and air rushes into the bottle. Think of it as an even exchange of water for air.

When the lid is on the soda bottle, air pressure can’t get into the bottle to push on the surface of the water. When the lid is uncapped, air sneaks in through the top of the bottle and pushes down on the water (along with the force of gravity) and the water squirts through the holes in the bottle.

Want more information? Read the experiment on the Do Not Open Bottle at SteveSpanglerScience.com.