Copyright © 2006, by The Science House (sciencehouse.ncsu.edu)

Not Popping a Balloon With a Needle Physics Concept

A balloon pops because the rubber is stretched. When it is nicked with a needle the rubber pulls away rapidly and the higher pressure inside the balloon causes the "POP!" If the balloon is nicked where it is not stretched, it will not pop. Some things that appear to be magic are really physics.

Materials

A balloon and a needle or a straightened coat hanger that has been sharpened at one end. A little grease, glycerin or WD-40 on the needle helps.

Method Blow up and tie the balloon. Using all of the showmanship you can muster, insert the needle into the balloon near where you tied it and out the "dimple" at the other end. Pop the balloon after you remove the needle.

Questions An inflated garbage bag will not pop in the same way. Why?