Do Not Open Bottle - Soda Prank
It's the ultimate prank using 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. Watch out, the fun is just beginning!
- Two plastic soda bottles (1-liter size works well)
- Large nail
- Deep sink or large pan
- Sharpie pen
Hey, if you're a kid who is trying to do this experiment, get an adult to help you poke the holes in the bottle. You don't want to hurt your hand!
The Leak-Proof Bottle
- Use the nail to poke a hole on the side of the bottle close to the bottom.
- Cover the hole with your finger while you fill the bottle with water all the way to the top. Screw on the cap.
- Slowly take your finger away from the hole. Are you ready for the water to come rushing out? Hey, there's no leak!
- Unscrew the cap and watch what happens. Okay, now it's time to stand back!
The "Do Not Open" Bottle Trick
- Start with a new plastic soda bottle (don't use the one from the previous experiment). Clean and dry the bottle and remove the label.
- Use the permanent marker to write" DO NOT OPEN!" in fat letters on the bottom half of the bottle.
- Carefully, use a sharp push pin (thumbtack) to poke tiny holes through the bottle along the lines of all the letters (the letters will help hide the holes).
- Place the bottle in a deep sink or pan and fill it with water. This is the tricky part. Water will leak out of the holes as you're filling the bottle. Keep the water running as you screw on the cap. Don't squeeze the bottle or it will start leaking before you're ready.
- Carefully set the bottle on the kitchen counter (word-side out) where someone can see it as they pass by. Stay close enough to watch what happens. Eventually, someone is bound to ask about the bottle. Play dumb with, "I dunno," when they ask about it. Let them unscrew the cap and you'll witness science in action!
How Does It Work?
Let's start by examining an empty soda bottle. Is the bottle really empty? No. The bottle is filled with air (gotcha!). 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.
You might think that poking a tiny hole in the bottom of a bottle would cause it to leak, and it does if air molecules can sneak into the bottle. When the lid is on the soda bottle, air pressure can't get into the bottle to push on the surface of the water. The tiny holes in the bottom or sides of the bottle are not big enough for the air to sneak in. Believe it or not, the water molecules work together to form a kind of skin to seal the holes - it's called surface tension. 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.
It's kind of a tag team combo between gravity and air pressure. Gravity is pushing downward on the water whether the lid is on the bottle or not. Air pressure can't do anything until it somehow gets into the bottle. When the lid is on, air pressure can't get into the bottle to push on the surface of the water. It does, however, push against the outside of the bottle on all sides. Since the outside atmospheric pressure is greater than the force of gravity, most of the water stays in the bottle. When the lid is uncapped though, the outside atmospheric pressure (14.7 pounds per square inch at sea level) and the force of gravity push down on the water at the same time. The water shoots out and the nosy person gets a scientific (but well-deserved) soaking.
- Super Cool Review by Max Witherstone
This is the coolest project (and prank) there is!
(Posted on March 16, 2010)
- Nice trick! Review by B R Sitaram
I use a variant with my shows: I prepare a bottle with two holes, one near the top and one (diametrically opposite) near the bottom. I fill the bottle with water and cap it, taking care to close the upper hole with my thumb. I call someone from the audience and hand over the bottle; when he/she takes it, obviously the upper hole is now open and the water comes out of the lower hole, drenching my victim.
(Posted on July 23, 2012)