Now, you may have seen Ruben's tube before. That's basically a pipe with a bunch of holes in it, and you pump inflammable gas, and light it on fire, so you basically create a row of Bunsen burners. What's really coolis to play some sounds into the tube, and you can actually set up standing waves. Thatis, 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'stube, a whole plane of Bunsen burners, effectively. How many holes in this tube? - 2,500 - 2,500 in this Pyro Board? - Yeah - 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. - Why did you make this? - Because, we really liked 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 - So what are we seeing here?
It's pretty much like the standing wave on Ruben's tube. It's just in this direction. This is the lowest frequency that makes a standing wave in this pulse. - So this is like the fundamental. - It's fundamental. - Can you show me what happens when you vary the volume a little bit? 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. - 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 ina node. - Because you can measure the sound pressure? - I can hear it. Like here is very much an anti-node. - I never thought about that. - This is a node, and you guys can hear it. - That's true. - It's incredible. The flames must be coming out in the anti-nodes. - The flames are coming up in the anti-nodes, yeah. - And you can even hear it. That incredible. - Yeah, It's nice that it can do that. - That is awesome. - We just learned something. - What happens if we try to go higher frequency? - Yeah. We have something. Oh, that's a good one. - That is crazy. We're right in the anti-node. - Are your ears okay? - Oh, God! - My ears are hurting now. - That was painful. Why don't try to put something more pleasing to the ear through the speaker and see what happens? - I think that's a good idea.
Let's put some music on there. You ready? - Go.- 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. - That is the actual Czech word for hello. I have made it to Olomouc in the Czech Republic, and this is partly thanks to supporting from Audible.com, the leading provider of audiobooks, with over 150,000 titles in all areas of literature, including fiction, non-fiction, and periodicals. Now, today I wanted to recommend the 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.
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