Summertime is here and things are getting hot, hot, hot! This experiment harnesses the energy of the sun to pop a balloon, letting all future scientists explore concepts around heat and light.
- 1 Clear Balloon
- 1 Black Balloon
- 1 Magnifying Glass
- A Sunny Day
- Adult supervision – adults can blow up the balloons for children and provide help tying off the ends
- Blow up the clear balloon but don’t tie the end…yet.
- Insert the black balloon into the clear balloon and keep some of the opening of the balloon outside of the clear balloon.
- Blow up the black balloon so it’s about half the size of the clear balloon and tie off the end of the balloon.
- Push the black balloon the rest of the way into the clear balloon and then tie off the clear balloon.
- Take the balloons outside and use the magnifying glass to focus sunlight on to the black balloon inside the clear one and watch what happens!
One POP but not Two!
The black balloon pops inside the clear balloon but the clear balloon doesn’t pop. Why do you think that is? The rays of the sun are incredibly powerful. When the rays are focused on one spot you’ve created an intense spot of heat. This spot of light is absorbed by the black balloon which means it also absorbs all the energy from that light. The balloon weakens and can’t contain the air inside.
The clear balloon is different. Light and heat pass through the balloon’s surface similar to a glass window, clear cups or a pair of eyeglasses.
If you want to expand on the experiment you can change the color of the internal balloon. What happens if you use a yellow or pink balloon on the inside? Does it take a longer or shorter time to pop?