Let's think about Lightning - Smarter Every Day 15

2m read

·Nov 3, 2024

[Music] [Rainfall and thunder] Hey, it's me, Destin.

So I'm gonna explain why thunder sounds the way it does. And uh, we're in the middle of a thunderstorm here, obviously, so I'm going to try to make this quick.

So basically, if you're standing on the ground here, and let's say there's lightning that happens way up in the sky, really far away from you. So what happens is, as soon as it breaks the sound barrier, that sound wave starts traveling towards your body. But also, the speed of the electricity of the lightning bolt is a lot faster than sound, so that... Oh wow, that's going to be a big one. At least I could see it.

So also, that lightning bolt... [Thunder] outruns the sound. So the sound is simultaneously initiated from all points along the lightning bolt, at the same time. So what happens is you get some cracks that happen before other cracks and you get this low rumble. So you might get... [Thunder] a really low rumble, like that.

So what happens is, if the lightning bolt is really really really far away from you, then all the sound might make it to you at the same time. But sometimes you get this long drawn out thunder rumble, and that's because the sound is coming to you at different points from along the bolt. It has to do with the distance of the lightning bolt, your position and the sound.

So there you go. I know that's not in-depth at all, but I'm in the middle of a thunderstorm. But I hope you're smarter every day and you at least get to think about it. Have a good one. [Thunder]

[Music] ...Good at this, so... I'll show you.

Watch his head stay totally stationary as I move his body. I can move his body in pretty much any direction. Captioning in different languages welcome. Please contact Destin if you can help.

Proof of p-series convergence criteria | Series | AP Calculus BC | Khan Academy

Types of health insurance plans | Insurance | Financial Literacy | Khan Academy

View All

Paying yourself first | Budgeting and saving | Financial Literacy | Khan Academy

You might have heard the term “paying yourself first,” and this just means putting your safety, your needs, especially your future needs, first before you think about other things. So let’s give ourselves an example. Let’s say that you want to buy a lapt…

Hershey and Chase conclusively show DNA genetic material

In the last video, we began to see some pretty good evidence that DNA was the molecular basis for inheritance. We saw that from the work of Avery, McCarthy, and Mlead, where they tried to identify whether it was DNA or proteins that acted as a transformat…

How to Make Time for Language Learning with a Full-Time Job

If you have multiple responsibilities in life, such as juggling your job, maintaining your health and wellness, trying to communicate and socialize with your partner, friends, and family, and also if you struggle to find time to squeeze in language learni…

Homeroom with Sal & David C. Banks - Thursday, September 10

Hi everyone, welcome to our homeroom live stream. Sal here from Khan Academy. Really excited about the conversation we’re about to have with David Banks, who is really one of the leading educators in the country, president of the Eagle Academy Foundation.…

Underwater Cave Diving | Best Job Ever

When you tell people that you do tape tiling, they say, “Oh, you must be an adrenaline junkie!” But in fact, it’s the exact opposite. When I get underground and underwater, it’s a hundred percent focus, and all you hear is really the sound of your own bre…

The Billion Ant Mega Colony and the Biggest War on Earth

In nearly every corner of the earth, ants wage war against each other. Their weapons are what nature gave them. Some have strong armor, deathly stingers, or sharp mandibles. And then there’s this tiny and not very impressive ant, but it rules the biggest …

Let's think about Lightning - Smarter Every Day 15

More Articles