yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Sound + Fire = Rubens' Tube


2m read
·Nov 10, 2024

So Dr. Phil, uh, what's going on here?

Okay, what we've got here is a metal pipe with a whole lot of holes in it. We're pumping gas through it, and we've lit it up, as you can see. So we have like a whole lot of, uh, buns and burners all in a row—a whole bunch of little flames burning gas. And um, this is all very pretty, but what does it have to do with science? Just you wait. I've got a speaker on the end here.

Whoa! So there you go, you're pumping a sound through the pipe. Now, is that right?

That's right. It's quite an annoying sound, Phil. Let me change [Music] it.

Okay, a few changes happening.

Yeah, so there's these areas where the flame is higher and other areas where the flame is not as high. What's causing that?

Well, it kind of looks like a wave, doesn't it?

Yeah, it definitely does look like a wave. But I mean, what is it showing us? Why has it got these high points and low points?

Well, sound is a wave. When I speak, my vocal cords vibrate the air, which sends a wave to your eardrum, vibrates your eardrum, and that's how you detect sound.

Okay, so how is this sound wave changing the height of these flames?

Well, the wave is actually areas of high pressure and low pressure in air. So there's actually a sort of compression traveling through, and that's what we can see is the pressure in the pipe here. There's areas where there's high pressure and areas where there's low pressure, and that results—the higher pressure is obviously pushing the gas out, uh, faster, and so we're getting these higher flames.

That's right, in a simplistic way. Pretty complex situation. But what about if we change it?

So you made it a higher pitch now, and I noticed that these peaks are sort of getting closer together.

That's right, yeah! So we've actually changed the wave by having a different frequency. We've made a short, shorter wavelength. We've changed the sound wave—changed the sound wave; we've made a higher pitch, so that's a higher frequency. Yep! It's vibrating faster, and to get all those vibrations in, it has to do it in a shorter space—in a shorter wavelength.

Shorter wavelength.

Okay, but uh, this is all very interesting, but you know, it's killing my ears! So what are we going to do?

Let's go for something a bit more musical, shall we?

All right, let's try a fairly simple tone. So I'll just [Music] whistle.

[Music]

So that's, uh, not bad. Let's have a listen to someone singing— you know anyone who can sing a bit?

I don't know anyone who can really sing.

Oh jeez! All right, it's just that you and me are made of these.

Hey, do you know any Mozart?

I don't. I'm sure—I'm sure you know a bit of Mozart. Maybe you heard it in the womb! Here, go have a try of this.

Okay, I'll just warm the orchestra up. Ready, you guys?

[Music]

[Applause]

[Music]

Than [Music]

[Applause]

[Music]

Very good.

More Articles

View All
Indefinite integrals: sums & multiples | AP Calculus AB | Khan Academy
So we have listed here two significant properties of indefinite integrals, and we will see in the future that they are very, very powerful. All this is saying is the indefinite integral of the sum of two different functions is equal to the sum of the inde…
Don’t Rely on Credibility Stamps
There are a lot of institutions in our society today that are relying upon credibility stamps. They used to be how you gain credibility in society. So, if you were a journalist writing for the New York Times or Washington Post, then you had the masthead o…
15 Financial Lessons You Need To Be Aware Of
Financial literacy is an indispensable life skill that empowers individuals to navigate the complex landscape of personal finance. This way, they can make informed decisions and secure their financial future. Whether you’re at the beginning of your financ…
Save the Ocean, Save Ourselves | Sea of Hope: America's Underwater Treasures
There’s been this arc to my career in the sense that in the beginning I just wanted to make beautiful pictures. But I began more and more to see all these problems happening in the ocean. Fewer fish in the places I used to see many fish, or not as many sh…
He Spent His Career Studying a Frog. Then He Discovered Its True Identity. | Short Film Showcase
[Music] So, after all the different tree frogs, there is one group that really captivated my interest, and that was the leaf frogs. You can just imagine seeing one of those in the wild; it’s just incredible. You know, the great big eyes open, they’ve got …
Khan Academy Sample Zoom Class
Hey everyone, this is Jeremy Shifling at Khan Academy. Um, thank you so much for making time out of your busy back-to-school season to join us today. You know, there’s a ton going on in your class and in the world, and so I want to make the next 30 minute…