Do Not Open Bottle - Soda Trick
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.
Materials
•Two plastic soda bottles (1-liter size works well)
•Cap
•Large nail
•Sharpie pen
•Thumb tack
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!
Experiment
The Leak-Proof Bottle
1.Use the nail to poke a hole on the side of the bottle close to the bottom.
2.Cover the hole with your finger while you fill the bottle with water all the way to the
top. Screw on the cap.
3.Slowly take your finger away from the hole. Are you ready for the water to come
rushing out. Hey, there's no leak?
4.Unscrew the cap and watch what happens. Okay, now it's time to stand back!
The "Do Not Open" Bottle Trick
1.Start with a new plastic soda bottle (don't use the one from the previous
experiment). Use the permanent marker to write DO NOT OPEN! in fat letters on the
bottom half of the bottle.
2.Use a sharp push pin (thumb tack) and carefully poke tiny holes through the bottle
at the bottom of the letters (the letters will help hide the holes).
3.Place the bottle in a deep sink or pan and fill it with water. The tricky part is that the
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.
4.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, œI dunno when they ask about it. Let
them unscrew the cap and you'll witness science in action!
How does it work?
Think about why the bottle spews water when the cap is loosened. It's kind of a tag
team combo between gravity and air pressure. Gravity is pushing downward on the
water whether the lid's 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.
Experiment From Steve Spangler Science
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