GRAND RAPIDS, Mich. (WOOD) — This is a great kid question that some adults don’t even know the answer to! Connor and Ethan would like to know how is lightning made, and what makes the thunder sound?


Believe it or not, scientists are still not 100% sure what creates lightning. The most logical explanation as of now has it all starting with ice crystals and turbulence!

As clouds grow high in the sky they enounter much colder air. Thunderstorm clouds, or cumulonimbus clouds, are the only type of cloud to form closer to the surface and surge all the way up to as high as 30,000 to even 60,000 feet into the air! As the cloud grows higher into the sky, it encounters colder air. The individual cloud droplets start turning to ice crystals, which is an important step to lightning!

Ice crystals inside the thunderstorm cloud aren’t standing still. In fact, they are being thrown around like crazy and bumping into each other in the intense wind inside the storm. As these ice crystals bump together, they start building up electric charges. This is static electricity!


Electric charges will start stacking up inside a thunderstorm cloud over time and organizing. Negative charges in the clouds group up with the other negative charges, and the positive charges group up with the other positive ones.

As more and more ice crystals bump into each other, more and more electrical charges build up inside the cloud until there is just too much energy and the cloud has to discharge it! A bolt of lightning, which is like a giant bolt of static electricity, is formed!

The cloud will discharge electricity with bolts of lightning until it is finally in balance again!


Put on some socks and find some carpet. Take turns sliding around the carpeted floor, rubbing your feet vigorously on the carpet. After about a minute walk to a metal door knob and try to touch it! There is a good chance a mini-bolt of lightning will form, jumping from your finger to the knob! This is an example of static electricity and how the imbalance needs to be discharged with a bolt of electricity!


As for thunder, it is formed because of lightning. Believe it or not, a single bolt of lightning is five times hotter than the surface of the sun! Every time a hot bolt of lightning cuts through the sky, it heats the air up rapidly. When air heats up, it does something really neat! It expands!

The air heats up so much and so fast from a bolt of lightning that the expanding air makes a loud BOOM! Thunder is the sound of air expanding!


We can see a similar thing happen with popcorn! Kernels of popcorn get so hot that they burst open and expand with a big pop!

This is a fun experiment to do at home. With a parent’s help, have kids take a single kernel of popcorn with a pair of tweezers and place it in between the hot plates of a hair straightener!

If we think of the kernel as a parcel of air we can see how it can make a noise when it heats up and expands! A mini thunder-maker!