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- Just press play, you mean?
- [Voiceover] Yeah, go for it. Whoa!
[Music]
- Now, you may have seen a Ruben's tube before. That's basically a pipe with a bunch of holes
in it, and you pump in a flammable gas, and light it on fire, so you basically create
a row of Bunsen burners. What's really cool is to play some sounds into the tube, and
you can actually set up standing waves. That is, there are areas, there are patterns of
the vibration of the air where there's a lot of vibration in some parts, and not very much
vibration in other parts. Now, that affects the flow rate of the gas inside that tube
into the atmosphere, and so it affects the height of those flames. So basically, you
can visualize the standing wave pattern. I'm currently in Denmark with a team of physics
and chemistry demonstrators who have taken this experiment to the next level. They've
actually created a two-dimensional Ruben's tube, a whole plane of Bunsen burners, effectively.
How many holes in this tube?
- 2,500
- [Voiceover] 2,500 in this Pyro Board?
- Yeah
- [Voiceover] So we're gonna see 2,500 little flames. Yeah. So, do you want to light it
up?
- Yes, I really want to light it up.
- [Voiceover] Why did you make this?
- Because, we really liked the Ruben's tube, but then we thought, "when you put on more fire, then it always gets better."
Let's just turn [the frequency] down
...and then we can just find the standing wave.
So, this is below the normal standing wave
- [Voiceover] So what are we seeing here?
- It's pretty much like the standing wave on the Ruben's tube. It's just in this direction.
This is the lowest frequency that makes a standing wave in this pulse.
- [Voiceover] So this is like the fundamental.
- It's the fundamental.
- [Voiceover] Can you show me what happens when you vary the volume a little bit?
- [Voiceover] Whoa! That was awesome. Okay, should we try to find another standing wave?
- Yes
You can see it. You can see it. You can hear it before you can see it.
- Woah
- [Voiceover] It's weird. With the microphones, I can actually hear, like here, I'm in a node.
And then here, I'm in an anti-node. Here I'm in a node.
- [Sune] Because you can measure the sound pressure?
- [Voiceover] I can hear it. Like here is very much an anti-node.
- [Sune] I never thought about that.
- [Voiceover] This is a node, and you guys can hear it.
- [Sune] That's true.
- [Voiceover] It's incredible. The flames must be coming out in the anti-nodes.
- The flames are coming up in the anti-nodes, yeah.
- [Voiceover] And you can even hear it. That’s incredible.
- Yeah It's nice that it can do that.
- [Voiceover] That is awesome.
- [Sune] We just learned something.
- [Voiceover] What happens if we try to go higher frequency?
- [Sune] Yeah. We have something. Oh, that's a good one.
- [Voiceover] That is crazy. We're right in the anti-node.
- [Sune] Is your ears okay?
- [Voiceover] Oh, God!
- My ears are hurting now.
- [Voiceover] That was painful. Why don't we try to put something more pleasing to the
ear through the speaker and see what happens.
- I think that's a good idea.
- [Voiceover] Let's put some music on there. You ready?
- Go.
[Music with bass thumping]
- So, you go around Denmark showing kids all about physics?
- We do. That's what we do.
- You show them the Pyro Board?
- We show them the Pyro Board, and we show them a whole lot of other stuff.
- You guys are also on YouTube?
- Yep, we have a YouTube channel. You can go to this link, right here.
- Go check it out if you want to see more of what these guys are up to. It's awesome.
- [Sune] It's great.
- Ahoy. That is the actual Czech word for hello. I have made it to Olomouc in the Czech
Republic, and this is partly thanks to support from Audible.com, the leading provider of
audio books, with over 150,000 titles in all areas of literature, including fiction, non-fiction,
and periodicals. Now, today I wanted to recommend a book, which is a little bit European, and
it's called Galileo's Daughter by Dava Sobel. I love this book because it includes the actual
letters written from Galileo's daughter to him during his life, and it really reveals
what he must have gone through as a human being. We all know about his science, and
about the trials that he went through, but to see this kind of insight into his personal
life, I think is remarkable, so you should really check out this book, and you can download
it for free by going to audible.com/veritasium, or you can pick any other book of your choosing
for a one month free trial. So I really want to thank Audible for supporting me, and allowing
me to go and meet great scientists, and filmmakers, and lots of people all around the world. Also,
I should note that I will be hosting Michio Kaku in Brisbane and Melbourne on June 5th
and 6th. Links in the doobly-doo. I would love to see you there. Thank you so much for
watching, and I will see you somewhere else in the world. Bye.