Hooked on Science: Pop a balloon inside a balloon

It's possible to pop a balloon that's inside another balloon, without popping the out balloon. Find out how.

Materials

• Magnifying glass
• Black balloon
• Clear balloon

Instructions

STEP 1: Push the black balloon inside the clear balloon. Inflate the black balloon. Tie the black balloon.

STEP 2: Inflate the clear balloon, so the black balloon can move freely inside the clear balloon. Tie the clear balloon.

STEP 3: Using the magnifying glass, focus the sun's rays through the clear balloon, to the black balloon and observe.

Explanation

The black balloon pops quickly. The magnifying glass allows you to concentrate the sun's rays through the transparent balloon to one spot on the opaque or black balloon, which eventually weakens the rubber, causing the balloon to pop. The black balloon pops, while the transparent balloon stays inflated. The reason: the color of the black balloon. Black absorbs the sun's rays, causing the balloon to heat up faster.

Jason Lindsey is a science outreach educator with Hooked on Science. Check out his website, hookedonscience.org, for webcasts and experiments.