When there is a storm, we often see lightning and hear thunder. This lesson will teach you what thunder is, how it works, why thunder makes different sounds, and some other cool facts about this stormy occurrence.
What is Thunder?
It’s finally the weekend and you have been waiting all week to go outside and play with your friends. Just as you put your shoes on, you hear it. There is a deep rumble across the sky as dark clouds move in. The last thing you wanted to hear was thunder because it means a storm is coming and you can’t go hang out with your friends.
Thunder is the loud sound you hear after a lightning flash. Lightning is a bolt of very hot electricity that also makes the air around it very hot. In fact, that air can get as hot as 54,000 degrees. That’s about 44,000 degrees hotter than the surface of the sun!When air gets hot, it gets bigger.
A balloon that has been stretched over the mouth of an empty plastic bottle will inflate when the bottom of the bottle sits in a bowl of hot water, heating up the air in the bottle. This happens because the air has warmed up, expanded, and the bottle can’t hold it all.Just like the air in the bottle, the air around lightning gets bigger, too. But this happens really fast, like a giant blast, because it’s so hot. It smashes into the colder air around it, cools off fast, and shrinks again quickly, making a sound wave that we hear as thunder.
Thunder Makes Different Sounds
If you are very close to the place where lightning hits the ground, the thunder you hear might sound like a deafening bang.
Sometimes you will hear a crackling sound, like the sky is splitting in two. This is the sound the air makes when it is cooling and shrinking.
Thunder also sometimes sounds like a low grumble, tumbling through the sky. This is caused when the air continues to shake and shudder from the lightning bolt.
Where There’s Thunder, There’s Lightning
You can’t have thunder without lightning, and lightning is dangerous.
If you are in the middle of a storm, you will probably see lightning before you hear thunder because light moves faster than sound.But sometimes you hear thunder before you ever see the lightning of a storm that is farther away. If you can hear thunder, you are close enough to be struck by lightning and should go inside to be safe right away.