How to Make Thunder

This is a super easy experiment that’s especially great for younger kids! It can help you teach the principles of thunder and why you always hear the thunder several seconds after you see the lightning. The only thing you need for this experiment is a paper bag.

Open the bag and blow air into it to slightly inflate the bottom. Then close it off at the top with your hand to keep all that air inside. 

*This will make a loud noise, so prepare your audience ahead of time if you think that is necessary*

Using your free hand, smash the inflated end of the bag. It will rip a hole in the bottom of the bag from the compressed air trying to escape. This is similar to what happens during a lightning stroke. Lightning is so hot it literally burns a hole in the air around it like the whole you created by popping the bag. 

From the location where you popped the bag, sound waves travel out. Where you are standing the sound was almost immediate after you popped the bag. But if someone stands in the next room, they will not hear the sound immediately. It will take several milliseconds to travel to them. Thunder originates from the point of the lightning, but then it takes several seconds to travel to where you are miles away. Just like ripples in a pond, sound travels out from the point of origin in waves (or ripples). 

If you watch the video on my IGTV on Instagram, you can hear how the sound echoes through the TV studio