Breakdown: Flash! Boom! Why lightning leads to thunder

Flash! Boom! Why lightning leads to thunder

MEMPHIS, Tenn. (WMC) - The flash of a lightning bolt, it only takes a few thousandths of a second for it to skirt across the sky. As always, a loud thunder will follow the lightning strike, but where does the grumbles and growls of a storm originate?

In this episode of the breakdown, we will explain why you can’t have that iconic thundering sound without a strike of lightning.

Lets first refresh what causes lightning. In the cloud above the ground, frozen and liquid particles will rub next to one another in a build cloud. Eventually, those particles will separate, with the positive charges floating to the top of the cloud while the negative charges to the bottom. Positive charges from the ground below become attracted to the negative charges above, when the bond becomes so strong, they finally connect, creating a bolt of lightning.

Air surrounding that bolt of lightning can heat up to nearly 50,000 degrees Fahrenheit, which is three times hotter than the surface of the sun. The super-heated air cools and produces a type of resonating tube of air surrounding the path of the bolt.

The nearby air quickly expands and contracts, causing the column to vibrate and collapse quickly. That will sound like a drum and produce the cracking sound we hear. When the vibrations start to die out, it then continues to echo and reverberate, thus creating the thundering sound we hear after a lightning strike.

You end up seeing the lightning first before hearing the thunder. This is because the speed of light is much quicker to your eye than the speed of sound is to your ears. Thus, you see the flash then hear the thunder once this sequence takes place.

Due to this fact, if you were far enough away from the strike of lightning, you could see the bolt but never hear the thunder, as the sound waves would die out by the time it reaches your location. Some consider this as “heat lightning.”

On the flip side, it is not possible to have thunder without lightning. Thunder is a direct result of lightning, all caused by the heat creating a rapid expansion of air and back.

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