Barking Dog (slow motion) - Periodic Table of Videos
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- Опубліковано 12 чер 2013
- Barking Dog reaction at 3000 frames per second.
More about filming & editing this video: • Behind the Scenes - Ba...
The Barking Dog is combustion of nirous oxide (laughing gas) and sulfur dioxide.
This video features Martyn Poliakoff, Pete Licence and Darren Walsh.
More slow motion chemistry like this:bit.ly/chemslomo
More chemistry at www.periodicvideos.com/
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From the School of Chemistry at The University of Nottingham: www.nottingham.ac.uk/chemistry...
Periodic Videos films are by video journalist Brady Haran: www.bradyharan.com/
Brady's other channels include:
/ sixtysymbols (Physics and astronomy)
/ numberphile (Numbers and maths)
/ computerphile (Computer stuff)
Watch videos about EVERY element: bit.ly/VT9nNZ
Reactions filmed with a Phantom Miro. We used this: www.visionresearch.com/Product...
Special thanks to Destin from Smarter Every Day for helping us out: / smartereveryday
Music by Alan Stewart - / alankey86 - Наука та технологія
I love when people stumble on something so new and profound that their primary explanation is that they don’t know. It is in that moment of not knowing, that they live for because they’ve found another question that needs an answer. It’s truly beautiful.
It feels like a slow walk through a hanging garden of unicorn tails. The warmth and comfort remind me of some far off place in my childhood where I have limitless potential and I'm ignorant of all evil. So majestic.
in short it is amazing
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What the
The first man looks like science
H E
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scientist
Waaait didn't you say the same in another video
Now that I see the oscillation in the reaction, the loud sound the results now makes a lot more sense!
Would be interesting to hook up a pressure sensor a the bottom of the tube and sample at the same or close to the same speed as the high speed camera as well as maybe hooking up a microphone and sampling that as well and see how all three pieces of data correlate as well as to verify the correctness of the professors hypothesis.
Either way very cool, thanks
You know you have a boring job when your best form of entertainment is staring at colours change on a monitor. Great video as always guys.
The example used at 2:45 sounds amazing.
I repeated it a lot.
So majestic in its own way.
I was thinking at first that's really cool... then I realized if there wasn't some kind of oscillating pressure there wouldn't be anything to create a sound.
you're right. there's no chemistry content in this video. fun, though !
True! Never thought about that, but that was definitely surprising
It was oscillating much more than I expected
Knowing a reasonable amount about acoustics, I was thinking exactly the same thing!
Also the length in relationship to the diameter dictates what pitch it resonates at!
But then that means that chemists/physicists must have figured that out before, which means that from the fact that it makes a particular sound they knew it had to be oscillating within the tube. Then why are they presenting this observed oscillation as so much of a surprise?
I love that something done so often is able to provide such a great learning experience, not just to us non-scientists but even scientist, learning shouldn't stop and it doesn't stop, well done well done indeed!!
1:54
VOOOOOSH
😂😂😂
Gotta love the professor
I love how he is so enthusiastic and excited by chemistry, even at his wise age.
The barking dog always reminded me of a pulse jet, very loud and low frequency sound, now i see the flame kind of resonates like the one in a pulse jet, cool stuff!
The barking dog is my favorite reaction! This just made it even more exciting!! :D Amazing footage, both surprising and beautiful. Absolutely superb!
Whoever edits these videos has a great sense of humor.
oh man i hope for more slow motion videos soon, they are the most beautiful and give such insight into things
Delighted to see a review of Professor Poliakoff and his work in Chemistry World this month!
5:25 HEY! Look it's Michael from Vsauce! XD
Guys this was a really well produced and put together video, all you videos are usually very good, but this one stands out! Well done keep it up!
Awesome stuff once again! I live how everyone learns something new every day no matter how young or old they are!
Wow! I've been watching these videos for a few years, and I've gotta say this high-speed series is probably the most amazing yet.
I truly enjoyed the clips and voice-overs of Colonel Shaw. Thank you for including those bits. ~ Michelle
This is one of the most amazing videos I have ever watched in this channel.
Great video! I really enjoyed all the explanations and video clips
Now it's time to relate the ratio of descent and ascent of the flame front to pi, just like the bowling ball on the pool table. Nice job Brady!
it sounds like a carrera gt with straight pipes
Another brilliant video. Absolutely spectacular.
i love how the man in the older footage is lighting up the tube so nonchalantly.
Absolutely awesome video, thank you!! You can even see the harmonic. Node
Amazing that you've just learning something new about a demonstration you've seen hundreds of times. I assume much of the power of the sound being generated is due to the shockwave exiting the top of the tube. Also, if you capture the sound of the reaction in an audio program, you can see the frequency of the sound occillations increasing rapidly.
I really love the voice-over from the old videos!
I surely wasn't expecting it to look like this. Thank you for this awesome video.
Absolutely love the sound it makes!
Loved it in you Chemistry Dubstep video as well :)
I love the flame plumes chuffing out the top. So cool.
Surprised me how it moved down the tube like that. Never get tired of seeing these awesome slow motion. videos, always end up being surprised in some way.
Chemistry and slow motion footage is really a match made in heaven!
Very well edited! Well done!
wow this was just amazing! best slow motion video yet!
this just proves that this is the most badass experiment they have shown
the most intriguing thing about this to me, if when it's in slow motion if you look at the back draft coming out the back, while the flames look like it's obviously slowed down, the back draft looks normal, like as if it was just smoke from a chimney it's dispersing in such a normal way, not as if it's being thrusted out the end like i would have expected
I love how you share knowledge & science, thank you! Keep up the Good Work :)
Hm, if you look closely at the bottom part of the test tube thing during the slo-mo you can see condensation forming during every circulation and then disappearing just as quickly.
Another proof of it being a pressure wave from the flame front, I guess?
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+Irval Firestar I was thinking the same thing, pressures at both ends of the test tube was acting against each other; the combustion was propelling the flame down, the pressure build up and pushes it back up, but because the reaction is propelled down, when the pressure normalizes at the bottom, it gets pushed back down again.
@@hoseinqadam It is a bit more complexx than that, since there is also a pressure wave being reflected back down the tube from the mouth.
It is the same oscillatory burning you find in a pyrotechnics whistle - except the fuel is dispersed through the full tube length, rather than being compacted at the bottom.
I've been waiting for this one. Was not dissapointed.
This is the true heart of science. Not degrees, not journals, but this.
Most interesting: During the pressure Drop, as the shock wave ascends the tube, there's Vaporization/boiling-off of the water&solvent mixture a the tube's bottom. Very apparent if you watch the bottom of the tube closely from around 5:09 mark.
Classic experiment seen in a whole new light. Really causes you to pause and question all the things we thought we knew.
Also notice how when the pressure wave reflects off the bottom of the tube and is coming back up, it pushes through the flame, again pushing it up, but look at the top of the tube: some of the flame gets pushed out of the tube each oscillation. Very cool indeed
Great idea! I was thinking with every downward push of the flame the pressure must have been increasing, what an awesome way to test that!
That's probably part of why it's sound is so distinctive. Those oscilations are fast enough to be audible, although they're probably the lowest pitched part of the sound. Also, the fact that the oscillations get faster as the flame approaches the bottom is audible in the way that low frequency component of the sound get's higher and higher pitched as the reaction proceeds down the tube.
It may be too fast for the eye to see (except I think kind of saw it in one of the full speed examples in this video), but that just means that it's fast enough to hear.
That was actually a very interesting result, many thanks :)
6:20 with captions (The new of of red circle) All made by the slowed down experiment sounds! Keep the exciting videos coming, Periodic Videos!
This makes sense actually. Pyrotechnic (firework) whistles work based on special compositions that burn in an oscillatory manner called crepitation. The rapid chuffing causes the column of gasses inside the tube to oscillate at a frequency determined by the length and diameter of the empty space. Very large pyrotechnic whistles and large bore whistling rockets make more of a ripping sound somewhat like the barking dog.
I totally love that periodicvideos is now teaching the professors.
Always wows me seeing the brilliant blue flames chugging up out of the tube. I love seeing the blue flame at the bottom pulsing as the fuel burns down the tube. 👍
This is a most interesting video, and well done for Brady filming it. This, to me, strikes of two very different things that must be taken into account. Gas dynamics and chemistry, the pressure changes will come from the chemical reaction. So to be able to model this chemical reaction properly you need the combustion equations linked in to the equations of gas dynamics to understand how the two different fronts interact. It's a very very nice applied maths problem.
3:24 the little Lego doll made me laugh
This is an outstanding visualization of resonance in a tube. Pulse jet engines and pipe organs work on this same principal. If one were to change the length of the tube and or the diameter the frequency of the wave propagation will be changed and thus the pitch of the sound. There is a formula for calculating the frequency of the wave given the length and diameter of the tube. This was worked out during the middle ages by the early organ builders. Look up tuned pipes.
absolutely incredible!!!
This is arguably my favourite ever sound.
I remember seeing this done twice at the RI last year. It is even more interesting now I've seen it in slow motion.
This is amazing!
i think straight tubes are most common because they are easy to produce and easy to clean and nicely fit into a non-curved box. if you mess up a tube with sulfur and need to clean it later, picking a straight one is just the obvious and smart thing to do.
I love this channel
I thought the same thing...someone's Phd is in this video. I'm especially fascinated at how the plasma? above the flame front freezes and bounces in sync with the flame front. You'd think it would just burn off independently, but it doesn't. Fascinating.
Well said, this is touching, thank you
I think this video is a perfect example of why humans are intrigued by science. We might expect something, but the result might be very different. The journey that we embark on to understand and explain that difference is,and always will be the incentive that drives us forward. Kudos to you Brady and the rest of you guys @periodicvideos
Just incredible.
That is insane. The hypothesis about the pressure wave getting shorter in every stroke is very plausible.
It sounds awesome in the slow footage...
The rapid pressure waves are "kicking" resonant modes of the tube which is why it oscillates. Every geometry has resonant modes but depending on the "natural frequency" of the object, the reaction may not generate sufficient energy or bulk movement of the gas to excite modes of oscillation. Notice how the varying sized tubes made different pitched "barks".
Every time I see this experiment I've always noticed the slightly irregular burn but I never thought something as cool as this was happening. Science!
I really love the point, when a chemical reaction starts to look like an unrealistic special effect in a movie! This is so amazing!!!
Yes it is. He went to Nogha once. He also made a video about his trip to the university.
It is my hope that Martyn Poliakoff never dies, but just reaches equilibrium.
When I listen to my dogs bark (actual dog) audio recording and look at it on an oscilloscope, if you were to zoom in on the wavelength you can see the individual vibrato patterns. I love this because this is like a visual version of just that! The amount of vibrations in the sample and the shape in which is vibrates determines the way it sounds, for example...sine wave shapes determines the resonance (the acoustics of the sound) and the amount of vibrations/cycles/hertz in the given second of the sample determines the pitch. This initial sound is probably about 140hz but I wouldn't be surprised if you would get different sounds out of different sizes and shapes of tubes. =)
It makes sense, it sounds like its a very low pitch, which means the pulsing of the flame is generating most of the sound, with probably resonance in the tube. It also explains why the pitch increases when the flame front gets lower
The professor is on top of the world (:
I honestly think you guys could have reeled in a few million views with this awesome experiment if you had given it a title like "Most Insane Chemical Reaction", because the insanity is there, so once people see it they really won't be disappointed. Great videos keep em up:)
Amazing, stunning
It's great that we are discovering new things all the time now about subjects people thought were settled science.
This is glorious!
this man deserves about 1 million more views
I remember seeing such a reaction in a huge spiral test tube which went really slowly at first and then sped up more and more. I don't know if it was this reaction exactly but it also oscillated and you didn't need a high-speed camera to see it. I'd suspect the same reasons for the oscillation, too.
Can't find that darn thing anywhere on YT though.
That is really cool. If you watch closely tho the bottome of the tube when the flame front goes up, you can see some mist rising from the bottom. I bet there is a lower than atmospheric pressure at the bottom in that moment.
Build a Pulsejet!
The slow motion surprised me, hope we can see more footage from other experiments.
If you look closely in some of the slow motion demonstrations, especially the one starting at 5:05 or thereabouts, you can also see vapor condensing and vaporising off the tube's walls. That I think supports the shock wave theory very well, as the rapid changes in pressure would make the carbon disulfide go from vapor to liquid and back with the same frequency.
I'm surprised that it was surprising! There has to be some sort of vibration going on to make the "bark" sound - and the wavefront going up and down is it.
The sounds produced by this experiment make great samples to use in dubstep tracks
I think it may be an effect of the mass of the gas flowing from the top of the tube. As the burning gas leaves the top of the tube its momentum is acting like a plunger and drawing the flame front upwards and lowering the pressure of the gas below it. Hense why you see the vapour form. This will only last a certain length of time until the pressure drop is enough to draw the flame front downwards. This would set up an oscillation, very similar to the one that is used in pulse jets. The frequency change could be related to a perhaps decreasing density and hence mass of the material in the tube, or that the reduction in unburnt fuel changes the pressure/volume relationship of the system in effect changing the 'spring constant'
Gd
@Philbert de Mercey: I think that it has to do with the flame moving. When the flame moves upwards, it makes the particles at the top of the tube move away (maybe more energy and bigger vibrations because of heat). When the flame then goes back down, there is space for the particles on the top again, and they move down. These particles moving result in vibrations (sound waves) in the air. And the close the flame gets to the bottom, the faster it moves, which makes the frequency of the sound....
If you feel it of value, perhaps several pressure gauges or indicators could be moulded at regular intervals down the length of the tube to show, over a few experiments, just what sort of pressures this reaction is making.
I'm sure that even the final graph of time/mbar would even be fascinating.
Yeah, he did a special video with them guys once where he was talking about the best metal or element to make into a wedding ring or somethin' like that. It was quite a while ago.
You can see the sound waves at the top of the flame as it gets nearer the bottom. It reminds me afterburner "shock diamonds"
Amazing!
Beautiful.
I never knew Albert Einstein was still alive 😂
I thought I was going to see a video of a dog barking in slow motion. I was pleasantly surprised.
The noise the barking dog makes is the sound futuristic toilets make when you flush them
Is there a full version of the recordings of the old Thunder&Lightning lectures? I love watching those special lectures at the Royal Institution channel and would greatly appreciate seeing this one in its entirety.
I have a different theory, I believe the gases in the bottom become so compressed under the energy and force that it thickens to the point where the fire can't ignite it all at once, this is also helped by the small diameter of the pipe, and the noise is actually created due to oxygen or other gases trying to escape the tube all at once. I noticed an almost vacuum effect towards the bottom, it'd be interested to see if this experiment still worked the same on a larger scale and would also like to see the barking dog in slow motion but from a bottom view looking up to see if the fire has a inward dip on it.
Notice the periodic condensation cloud at the bottom of the tube. I think that indicates the pressure down there is oscillating quite a bit.
What's really fascinating me here isn't the bottom of the flame, it's the top and how firmly it gets pushed down with each bounce.