How to Make Lightning

Full disclosure: the spark from this experiment is impossible to capture on my iPhone camera, so I don’t have a video or picture to share with you of the result. You can see it with your eyes if you follow this experiment, though, so give it a try! And to those of you with nicer cameras than what I have, if you manage to capture this I would love to see it. 

What you need:

Balloon

Metal spoon

Wool fabric (optional)

What you do:

Blow up the balloon

Rub it on your hair for two minutes. You will feel your hair start to build up static much more quickly than that, but trust me you need to go the full two minutes. If you would rather not mess up your hair, you can rub the balloon on wool fabric. 

Turn off the lights as you continue to rub the balloon on your hair or fabric. After two minutes hold the metal spoon close to the balloon and slowly move it closer until you see the spark between the balloon and the spoon. 

Lightning forms the same way, but it’s hard for us to study. Much of what we know about lightning is still theory as opposed to hard fact that can be observed and replicated. Positive and negative charges build up in clouds just like you built up charges on the balloon and in your hair. We believe these charges come from all the different ice fragments rubbing together and moving around inside a cloud. The cloud just wants everything to be even - positive and negative charges all mixed together instead of separated. This is why cloud-to-cloud lightning is more common than cloud-to-ground lightning, because much of this difference in charge distribution can be solved between clouds. Sometimes, though, charges also build up in the ground and in objects on the ground and it’s easier for the cloud to discharge through those objects than through another cloud. That’s what you just did - the balloon wanted all its charges to be even, so it discharged them through the spoon and now everyone is happy again.

This image from the National Severe Storms Laboratory helps explain the charge distribution in a cloud.

There’s a more complicated way to do this experiment, but I find this version much easier. If you’re interested in seeing a blog about the more complicated way, use the Contact Me form on this website to let me know and I’ll put a post together!