MOBILE, Ala. (WKRG) – In today’s Science Corner experiment, learn how to make thunder using just a brown paper bag!


STEPS (check out the video for a visual):

  1. Blow air into the brown paper bag
  2. Twist the top of the bag so the air is trapped inside
  3. Hit bag hard with hand


When you hit the brown paper bag with your hand, the force causes the air inside the bag to compress, the bag breaks and the air rushes out. The sound is caused by air escaping quickly. It is some of the same concepts for how thunder is formed.

When lightning moves through the cloud, it has a ton of energy and heat. Lightning heats up the air around it to over 50,000 degrees F. This is 5 times hotter than the surface of the sun! When the lightning heats the column of air, the air expands (because warm air expands), hits the cooler air outside of the column and contracts VERY QUICKLY. The crack and boom you hear (thunder) is that expansion and contraction happening so fast. The rumbles of thunder you hear after that initial boom, is the heated column of air vibrating. We often see lightning before we hear thunder. They actually happen around the same time, but because light travels faster than sound, we see the lightning first.