Why Lightning Comes Before Thunder (Mind-Blowing Science Explained!

[00:00:00]Have you ever counted the seconds between a lightning flash and the thunder that follows?

[00:00:06]Here's something crazy.

[00:00:08]>> [music] >> They actually happen at the exact same moment.

[00:00:14]So, why does [music] it feel like thunder is always running late?

[00:00:19]Let's find [music] out.

[00:00:21]During a thunderstorm, clouds build up a massive amount of electric charge.

[00:00:26][music] Kind of like static electricity, but millions of times stronger. [music] When that charge gets big enough, it needs to release.

[00:00:37]>> [music] >> And it does that in one dramatic burst.

[00:00:41]Lightning.

[00:00:43]Lightning is actually hotter [music] than the surface of the sun.

[00:00:48]For a tiny fraction of a second, it can reach [music] around 30,000 degrees Celsius.

[00:00:55]That insane heat causes the air around the lightning bolt to expand outward [music] incredibly fast.

[00:01:04]Almost like a tiny explosion.

[00:01:07]This rapid expansion [music] creates a powerful shockwave through the air.

[00:01:13]And that shockwave is [music] exactly what we hear as thunder.

[00:01:19]So, here's the key part.

[00:01:21]The flash [music] and the boom are actually born at the exact same [music] instant from the exact same event.

[00:01:31]So, why don't we experience them together?

[00:01:35]It all comes down to speed.

[00:01:38]Light [music] is incredibly fast.

[00:01:41]It travels at about 300,000 km [music] per second.

[00:01:46]That's fast enough to circle the entire Earth seven times in just 1 second.

[00:01:55]Sound on the other is much, much slower.

[00:01:59]>> [music] >> It only travels about 343 m every second.

[00:02:06]That's over 870,000 times [music] slower than light.

[00:02:12]So, even though lightning and thunder start at the same moment, light [music] reaches your eyes almost instantly, while sound has to slowly travel through the air to reach your ears.

[00:02:26]And that gap is what creates the delay you notice. [music] Here's a fun trick you can use next time there's a storm.

[00:02:36]Count the seconds between the flash [music] and the boom.

[00:02:40]Then divide by three.

[00:02:43]That number [music] tells you roughly how many kilometers away the storm actually is.

[00:02:50]So, if you count six seconds, the storm is about 2 km away.

[00:02:56]Getting closer?

[00:02:58]Time to head indoors.

[00:03:00]>> [music] >> So, next time you see a flash of lightning, remember, you're not just [music] watching light.

[00:03:08]You're watching one of nature's most powerful bursts of energy racing to reach you [music] at 300,000 km per second, while the sound takes its time catching up.

[00:03:23]If this made storms a little less scary and a lot more fascinating, hit subscribe.

[00:03:30]We explore a new science mystery every week.

[00:03:34]And tell me in the comments, what's the closest storm [music] you've ever counted?