Dinky Dirigible Deflation DENIED!

Dinky Dirigible Deflation DENIED!

Materials:

- Electric Drill with 1/8" Bit

- Clean, Empty Hard Plastic 2 Liter Bottle

- Medium Sized Toy Balloon

Procedure:

With help from an adult, drill a hole in the center of the bottom of the soda bottle. At the other end, insert the balloon into the bottle, folding the neck of the balloon over the bottle of the mouth. Inflate the balloon inside the bottle by blowing into it. Immediately place your thumb over the hole in the bottom of the bottle and remove your mouth from the bottle. Then remove your thumb from the bottom of the bottle While your thumb is over the hole the balloon remains inflated inside the bottle with it's mouth open. When you remove your thumb the balloon instantly turns inside out to inflate again above the bottle.

Explanation:

What's going on?
The hole in the bottom of the bottle lets the air escape as you inflate the balloon. Placing your thumb over the hole prevents air from entering the bottle to deflate the balloon. If you fill the inflated balloon with water and then remove your finger from the hole at the bottom of the bottle, the increase air pressure will push the water out.