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It’s almost summertime in Indiana, and that wonderful weather doesn’t last all season long. Thunderstorms are always right around the corner, but have you noticed that you always see lightning before you hear thunder? SciJinks has the explanation!
WHAT CAUSES LIGHTNING
Clouds are made up of water droplets. When those water droplets get caught in an updraft of wind and climb high into the air, they freeze into tiny bits of ice. Those ice particles in bump into one another, creating a static charge. Suddenly, you’ve got a storm brewing!
Protons go to the top of the cloud, and electrons go to the bottom of the cloud. Since opposites attract, the electrons in the cloud try to reach out to the protons in the ground below, and it looks for the tallest object to do that. That might be a tree, a skyscraper, or the weathervane on a house that gets struck by lightning!
WHAT CAUSES THUNDER
No matter how loud it gets, thunder can’t hurt you. Thunder is just a sound, and all sound comes from particles vibrating. When lightning strikes, it causes the particles in the air all around it to vibrate.
Since lightning is also very hot (up to 6 times hotter than the surface of the sun!), it makes the air around it expand very quickly, which creates more vibrations as the particles get pushed. All those vibrations can make a big boom, which you hear as thunder.
Another source of sound comes after the lightning fades. During the lightning strike, the electrons open up pockets in the air they cut through. When the electricity fades, air rushes back into those pockets. That makes a sound, which contributes to the sound of thunder.
SO WHY IS LIGHTNING FAST AND THUNDER IS SLOW?
That’s because light travels faster than sound. To be exact, it travels 882,353 times faster! So even though lightning and thunder happen at roughly the same time, you don’t hear thunder until much later than you’ve seen the lightning. It takes fives seconds for you to hear thunder that happened a mile away, but you can see lightning from around 100 miles away!
Looking for more Never Stop Asking "Why?" questions? Catch up on all of the past "Whys" on the blog!
