I found my type of people lol. It was so even in his pace and periodicity I couldn't help but feel satisfied even after continuing when the centre line has stopped. Bravo.
look at his wrist and the forearm while he's drawing it. very similar to a piano player having done their homework practicing legato slurs... never occured to me this helps improving sine drawing skills as well... btw. has anyone else spotted the grand piano with the pile of scores? ;)
This phenomenon is used practically in a lot of music for string instruments (guitars, violins, etc)! If you lightly hold a string down, you can double the frequency it vibrates at, causing it to ring an octave higher :) There are all sorts of variations on using this (touch harmonics, pinch harmonics, natural harmonics) and they're all very valuable to musicians :)
BunniBuu the touch harmonic happens because you force the second mode of vibration of the string by creating an artificial node, not sure it has anything to do with this 😬
Stargazer I'm no expert, but I thought touch harmonics produced two octaves since they first reduced the length of the string (as you mention with the node), but also create a harmonic the same way a natural harmonic would. I don't personally play any string instruments beyond an elementary level, so my knowledge of the physics of them could very well be off!
Btw if you tap the fork then roll it between your fingers, the Doppler effect between both branches will produce two notes, one slightly higher and one slightly lower than the fork « at rest », and the interference between these create yet another note.
Antonin Caors - this comment deserves to be upvoted more! That's fantastic. I remember waving tuning forks about when I was a kid, but I don't think I ever tried that. I will now :)
@@kaaiplayspiano7200 "Up" and "voted" have meanings independent of Reddit. The words existed first :) Had I written "liked", the nuance of the idea of voting for something *to make it rise higher on the page* would have been lost.
The thing he showed at the end with the bouncing so that only every second or third vibration hits excited me the most, because it's the first time I've see the subharmonic series represented in reality, and not just as a theoretical construct.
Is it actually a representation of the undertone series of the fundamental, or a new tone created in a new manner with its own overtone series? The fundamental frequency itself isn't convincing and I don't remember having seen anyone demonstrate with accurate measurements that actually produces an undertone series as opposed to just a new fundamental with a new overtone series with a different Fourier series approximation
This is giving us a pretty good look at how long your production cycle is. Hair for the interview. Bald a few videos ago. Hair growing out in the outro.
Preamble: I'm the Physics Demonstration Technician at a university. This is so cool! I had to stop the video and grab a tuning fork off the shelf about a third of the way in. I showed dozens of people around the physics department this effect and every one of them thought is was a very cool effect.
This is great stuff. I knew there was an issue with tuning forks and double/half frequencies, but only now I understand what it exactly is! Thank you so much. By the way I have two tuning forks, one labeled 440 Hz and an older one labeled 438 Hz. Fun to hear the beats when they go together!
I use a set of tuning forks to tune pianos, and from the start I noticed these same properties you discussed here. But I could never wrap my brain around the maths. Awesome explanation, gentlemen! Cheers! -Phill, Las Vegas
As a musician I have to voice this fact like others: It IS the same note. You said it yourselves, it's just an octave higher so it's still use the same note name What it is though is a different PITCH which is what directly correlates with the frequency of the vibration. I understand where you're coming from though and it's quite interesting.
As a musician I'd like to point out though that composing something out of unison (unisons? Sorry, english is not my first language) is different from using octaves, as a matter of fact. Though classic harmony has a set of rules that limit the same way both consecutive octaves and unison.
The base of your Tuning Fork "Round- vs Square-base" does different Resonance while touching the Table. The peak at the Second Frequencies on the square base caused by the Shape of the base. You see similar effects watching Resonance experiments with Different Material/Particles and different Resonance plates (Round vs Square). It's all about Creating an interference pattern in a mechanical resonance with a different Material shape. The force and the response of the Square structure form are in phase with one another, creating different resonance patterns by the form, and the energy in the vibration increases.
The Hz was reading as low by ~1 because you were in a room that was slightly hotter than the standardization temperature, causing thermal expansion of the metal tuning forks, lengthening them and thus lowering the frequency.
Overtones! Elements of this idea actually show up in Adam Neely's "SUBHARMONIC Music" video, so that may make for an interesting piece of further reading.
5:40 Yeah dude it's not going to annoy your musical friends because any decent musician already knows about the overtone series. It was a very nice demonstration of where the higher octave comes from. If you had a spectrometer that showed more than one frequency you would actually be able to see both the frequencies resonating at the same time although the higher octave would be significantly quieter. On most instruments it's common when one note is played for several different multiples of the fundamental to resonate as well. Those are called overtones and are exactly what you just demonstrated. The ear focuses on on the fundamental, but it hears the rest as well. It's what makes a piano playing one note sound different from a guitar or a French horn playing the same note.
Musicians typically won't be surprised you get multiple notes from one fork, as that is the principle of the harmonic series. A vibrating instrument causes notes an octave higher (double the frequency), an octave and a fifth (triple the frequency), two octaves (quadruple) etc. This is how a trumpet is able to play all the notes even though it only has 3 buttons.
5:45 "How can the one tuning fork be vibrating at 2 different notes at the same time?" The same way you are able to speak in a voice that's not a singular sine wave. I mean look at the harmonics on the app. It's already vibrating at lots of prominent frequencies. Good stuff, as always :)
There's some really cool stuff you do with the harmonic series using Fourier transforms and spectrograms which you can do with the human voice. Bit harder to do with other instruments because of the way they're tuned- that's really interesting as well.
Forgive me if this is basic and mentioned elsewhere but rotate an oscillating tuning fork around its vertical axis and hear the nodes and antinodes of waves in and out of phase. Great things tuning forks and they have many interesting properties and uses that are not all musical.
Regarding the thee-sided coin problem, I will be fascinated to learn that once the optimal ratio is discovered, how it makes sense mathematically (since it appears it will fit neither of the proposed hypotheses).
What is happening is that you are creating longitudinal waves down the mast as the forks are vibrating in and out, the mast is moving up and down, when you press the butt of the mast against a flat surface it is essentially trading a sustained ring for a shorter amplified ring by transferring the longitudinal waves into the flat surface of the table, like a speaker driver
I'm not sure if you could annoy the musician friends by saying there's two notes, in musical terms it's the same note in two different octaves, and the original note already contains the harmonic overtone frequency, but the original frequency overpowers it. The demonstration actually shows it pretty nicely where you can see the original frequency and the octave as the strong peaks but different levels when you touch. Also a fun thing to do is touching the ball end of the fork to your skull. Internal loudspeakers.
If you haven't read it yet, "Fundamentals of Musical Acoustics" by Arthur H. Benade was a mindblower for me. Also, how incredible is it that we have excellent oscilloscopes available as free apps on our phones?!? when i was in college, a used device that could come close to this would cost me a couple thousand dollars.
The waveform at the handle wouldn't actually be a sinusoid. It would be more like |sin(wt)|. The motion of the handle is akin to the signal coming from a full-wave rectifier, which is why its fundamental frequency is twice that of the tines, but spectrally it's actually quite different.
That last demonstration is a cool example of when the subharmonic series actually does appear naturally! You're getting integer divisions of your fundamental instead of multiples.
this can be done with ordinary forks as long as the style of the fork accidentally has a nice tone. It's a cute trick. Pluck a couple of the fork tines to get clear tone holding the fork just off the table. Hold fingers in a pinch near the fork then put your fingers into a glass while setting the end of the fork on the table just as your fingers go into the glass etc. Balancing the fork on a finger and allowing the fork end to barely touch the table will produce a buzz too.
Thats a logical explanation. I never noticed that. Went back to check it with my tuning fork and surprisingly it doesn't work. The top part of the fork and the "handle" at the bottom vibrate at exactly the same frequency. (even though I'm a musician, I know how to distinguish between different octaves). Now I'm confused. Can anyone explain this? (I have a smaller tuning fork, similar to the one Hugh showed in the beginning, tuned to 440 Hz, also the "branches" of the fork are more cylinder shaped, not rectangular like in this demonstration.)
I tried it too. I never knew the effect happened because my fork produces the same frequency. I double checked it with a tuner, and it is in the same octave, A4. Perhaps what we hear in our ear is the second harmonic and the fork is designed to supress the first.
an analogous effect was observed when electro boom and the slow mo guys filmed a tesla cool at a million frames per second- the arcs were strobing at twice the resonant frequency of the tesla coil because both the positive and negative peaks correspond to luminosity peaks in the plasma
How about a standing wave in the tuning forks stem? The stem oscillates up and down and should be tuned in length. I'm thinking standing wave ratio, like an RF antenna. Also, holding the fork introduces a node pretty much at the center (half way) of an already vibrating element. I don't have a tuning fork, but I wouldn't be surprised if by changing the way the fork is held, different results occur. This would inevitably change the ratio between the fundamental and the first harmonic. Maybe holding the fork higher or lower on the stem and/or rotating the stem 90° might yield interesting results.
I thought the conclusion would be that as the first tunning fork has a square shape, the vibrations don't flow on a spiral down the fork, making the tone go up an octave when the opposite vibrations combine at the base. With the second fork, the vibrations get to the higher octave at first, but then find their way up and down the fork on the same direction and flowing all in one, keeping the intended frecuency. Just as cilinders can take up more weight than a cube, as the force flows and gets a better distribution. Maybe compare two rounded forks with different bases, to see if that's what's making the vibrations flow steadly?
Fab, reminds me of something I discovered years ago and baffled a few people with: Why, if your domestic electricity supply is 50Hz (UK), do your lights flicker at 100Hz? Good luck 😉
I expected a little aside about how air conduction is stronger than bone conduction for humans... so that if you hold the butt of the tuning fork to the bone just behind the ear and wait for the sound to die off, then take it off and listen to the fork "normally", you should be able to hear the note again... though I wonder if the notes also differ by an octave!
Fascinating! Can you also explain why the ring when you hit the tuning fork is higher than the resonant frequency? For example, my 440Hz fork rings at what seems to be 6x higher (2640Hz, or two octaves and a fifth higher).
Hmm, my tuning fork doesn't have that effect it seems. Is that possible? It has an small scoop on the bottom of it, maybe that's compensating the octave change?
Hard boundary for internal wave reflection as opposed to soft boundary emphasizes the harmonic. The guitar harmonic selection comment is misleading. Finger positions on a guitar select the primary resonance length and tension, and likewise shift all resonances accordingly as opposed to selecting them.
I was not able to reproduce part 1 of this vid: the double frequency when put on the table vertically. The explanation seems logical, but the main frequency stayed the same (i.e. did not double). In the demo, I don't see a real frequency peak in the analyser graph. A pitty because it would have been amazing effect.
Guys, if you ask a musician they will tell you that it is the same note because it IS the same note. What you're doing is the same as if you fretted a stringed instrument at the half way point. You would get the same note different octave. Now can you isolate the overtone series based on the surface you use to amplify the tuning fork?
As a musician, I'm actually not that surprised that a tuning fork can play different frequencies in different situations. I would have been surprised however, if it wasn't a note which differs by and octave, a fifth or a fourth. Sound waves tend to act strangely, and usually when you hear a note, you're actually hearing many frequencies at once, the higher being a multiple (or near a multiple) of the lowest (that's called the harmonic series). The first intervals in the harmonic series are an octave, then a fifth, then a fourth (an octave above the first one) which is why I expected these changes.
it looked to be a lot more than 2 frequencies...when you used the spectrum analyser, you could see fundamental, 2nd order, and some of the higher order harmonics as well
The musical friends who say both notes are the same are still correct, because it is exactly an octave jump, which in music is the same named note, example A4 (440hz) to A5 (880hz) is still called A, even though they are in actave apart
I have a tuning fork that is cylindrical, so it oscillates rotationally, meaning when I put it against a resonant surface the same frequency is produced, not double!
as a pseudo-musician it doesn't surprise me to get different octaves out of one string. not just by pressing them on the frets, but by inducing a standing wave in the string, so effectively it only swings on half its length. or a third... whatever fret you lightly press on it before letting go...
For the fear of being too nerdy about it, but I think I might be in the right place for this, that is the same note. If you go an integer number of octaves from a note, you get the same note, albeit in a different octave.
i seem to recall i've heard a word you can stick in front of the word "note" which would make the claim correct. (the same way it would make it correct to switch out the word "note" for "pitch"). can you tell me what that is? intuitively i would go for "exact note", but i may be completely wrong. maybe there isn't even such an expression at all and i'm just misremembering something, or someone told me inaccurate information...
I think I have the solution, and I think you’re wrong. The higher pitch sound occurs when the teeth of the tuning fork are perfectly parallel, the more they are bent (inwards or outwards), the less you hear the high pitch tone. Once the amplitude of the vibration is smaller than the bending-angle, you don’t have the high pitch tone at all. For better understanding, picture a tuning fork that is bent open 180 degrees.
It would be interesting to know what would happen, if you put the fork down on the table at different angles instead of always at 90°. Shouldn't both frequencies crossfade the more you lower the angle?
I initially thought it was going to be something to do with the harmonic series, as the surface of the table isn't moving in a perfect sine wave like the fork
It's funny because at least in my speakers the mics are picking up more of the overtones, it's hard to hear the actual fundamental of the tuning fork unless it's placed on the table.
Us musicians are interested in whether you can highlight other positions in the harmonic series! We know you can get the octave, but can you highlight the fifth or even the third?
It's all a matter of ratios! In the same sense of cutting a string into smaller bits to get the harmonic series, you'd just have to make it vibrate faster!
I'm not sure about the fifth or the third, but if Hugh can accurately get the tuning fork to vibrate on the table every third cycle, he'd have a fifth DOWN from the original pitch of the fork.
My brother would like this, not because he likes math, but because he likes music... although, now that I think about it, one of his roommates likes math... (On a different 'note,' I have found that many two-pronged forks, like meat forks or toaster tongs, will act in the same way as a tuning fork, making a tiny tone when struck... just thought some people might find that interesting. [Watch now a bunch of people will be striking their forks to see if they vibrate. Please be careful with the meat forks!])
As a munition I feel the need to say that a musician saying it's the same note WOULD be right, because it's the same note an octave higher. Which in music is often considered the same thing. Still cool and science-y but to a musician it is the same note.
Interesting that the camera microphone only picked up the fifth harmonic at the beginning of the video (until they touched the tuning forks to the table)!
3:31 I’m trying to figure out if he just claimed that centripetal force and centrifugal force are interchangeable terms. Centripetal force is what he’s talking about. Not centrifugal force. They’re not the same thing.
how does that simulation work? I mean, if "we" are trying to determine proper ratio for some distribution, what goes into program for expected results?
Take a violin string and just touch it at half was bewegen fixed points, you will get a perfect octave up. Same on violas and cellos. Musicians call this flacholet (at least in Germany)
What’s the best iPhone app for trying this out? I’ve got a few but none of them show the dominant frequency in large text as in the video and I like that feature :)
Funnily, my tuning fork doesn't do this... Neither do I hear different pitches (and my hearing is very good), nor does the app on my phone, it is both 440 Hz...
I am a musician and I can tell when a note is an octave higher. I think the musicians he has asked are referring to the pitch class of the note, not the sounding octave...
I dont mean to sound like a dick or a genius or anything but it just made sense it would be double. 2 into 1 with the same output. It made me think back to Learning about waves with those really long springs they had in physics in high school and gave me an idea... Suppose you were to attach two springs to one and had one friend on the end of the one, holding it still. Then you and another friend, or just you if you could do it easily, grab the two ends of the double end. Hold them far enough apart so they wont physically interfere with each other and set them in wave motion, trying to maintain synchronicity. The amplitude in the one spring should be roughly double the height of the amplitude of the two springs. Would that work? Then you could actually see the effect on a much larger scale.
What if you have two forks of same frequency, and then touch their stems together? Depending on the phase, they might either cancel out or double, right?
To all you musicians out there, this is really only half the story. The frequency doubling is on top of the original frequency of the tuning fork. So instead what you hear is a change in timbre and not pitch, as the new frequency is in the harmonic series. Rest easy.
This video really resonated with me.
6:09 Best hand-drawn sine ever
It is so annoying when people use half circles!
I found my type of people lol. It was so even in his pace and periodicity I couldn't help but feel satisfied even after continuing when the centre line has stopped. Bravo.
Joshua Rando. It must really annoy you that most spheres and circles drawn by computer algorithms are using using sine and cosine curves.
look at his wrist and the forearm while he's drawing it. very similar to a piano player having done their homework practicing legato slurs... never occured to me this helps improving sine drawing skills as well... btw. has anyone else spotted the grand piano with the pile of scores? ;)
609 good numerology :)
This phenomenon is used practically in a lot of music for string instruments (guitars, violins, etc)! If you lightly hold a string down, you can double the frequency it vibrates at, causing it to ring an octave higher :) There are all sorts of variations on using this (touch harmonics, pinch harmonics, natural harmonics) and they're all very valuable to musicians :)
BunniBuu the touch harmonic happens because you force the second mode of vibration of the string by creating an artificial node, not sure it has anything to do with this 😬
Stargazer I'm no expert, but I thought touch harmonics produced two octaves since they first reduced the length of the string (as you mention with the node), but also create a harmonic the same way a natural harmonic would. I don't personally play any string instruments beyond an elementary level, so my knowledge of the physics of them could very well be off!
BunniBuu you do not reduce the length of the string but it's the whole string that vibrates with half the wavelength 🙂
Btw if you tap the fork then roll it between your fingers, the Doppler effect between both branches will produce two notes, one slightly higher and one slightly lower than the fork « at rest », and the interference between these create yet another note.
Antonin Caors - this comment deserves to be upvoted more! That's fantastic. I remember waving tuning forks about when I was a kid, but I don't think I ever tried that. I will now :)
@@macronencer not reddit it called like
@@kaaiplayspiano7200 "Up" and "voted" have meanings independent of Reddit. The words existed first :) Had I written "liked", the nuance of the idea of voting for something *to make it rise higher on the page* would have been lost.
The thing he showed at the end with the bouncing so that only every second or third vibration hits excited me the most, because it's the first time I've see the subharmonic series represented in reality, and not just as a theoretical construct.
You can also do it by touching a piece of paper with the fork, and you can also do it on a violin by pressing the bow very strongly on the strings.
Blad That makes me think maybe the action in vocal fry is actually using a subharmonic, since its made with very pressed vocal chords.
ZipplyZane Actually I think this is also the "beginner violonist sound". I saw this in a video by Adam Neely
Is it actually a representation of the undertone series of the fundamental, or a new tone created in a new manner with its own overtone series? The fundamental frequency itself isn't convincing and I don't remember having seen anyone demonstrate with accurate measurements that actually produces an undertone series as opposed to just a new fundamental with a new overtone series with a different Fourier series approximation
ua-cam.com/video/o4jgPdGrZYI/v-deo.html
This is giving us a pretty good look at how long your production cycle is. Hair for the interview. Bald a few videos ago. Hair growing out in the outro.
Jason Bailey I imagine they recorded a ton of these and he's releasing these slowly
Like his head releases hair?
Yet, the same shirt :)
Preamble: I'm the Physics Demonstration Technician at a university.
This is so cool! I had to stop the video and grab a tuning fork off the shelf about a third of the way in. I showed dozens of people around the physics department this effect and every one of them thought is was a very cool effect.
I am a musician and I never thought about that, i really enjoyed the video, more about tuning forks and music/Maths related videos please!!!
The tension on the rope of a swing while swinging made brilliant sense!! thanks! Long time fan of the channel
This is great stuff. I knew there was an issue with tuning forks and double/half frequencies, but only now I understand what it exactly is! Thank you so much.
By the way I have two tuning forks, one labeled 440 Hz and an older one labeled 438 Hz. Fun to hear the beats when they go together!
I like this one .. learning something never perceived / noticed before .. ty for producing and posting!
Never before have I seen such beautiful, hand-drawn sin/cos waves. Well, done Mat, at least you can draw that (cough - parker circle - cough)
I wonder if his hair grows in and out like a sine wave
Lol
I can draw a sum of perfect sin functions
I use a set of tuning forks to tune pianos, and from the start I noticed these same properties you discussed here. But I could never wrap my brain around the maths. Awesome explanation, gentlemen! Cheers! -Phill, Las Vegas
What an incredible simulation !
Great work Miako
As a musician I have to voice this fact like others:
It IS the same note. You said it yourselves, it's just an octave higher so it's still use the same note name
What it is though is a different PITCH which is what directly correlates with the frequency of the vibration.
I understand where you're coming from though and it's quite interesting.
As a musician I'd like to point out though that composing something out of unison (unisons? Sorry, english is not my first language) is different from using octaves, as a matter of fact.
Though classic harmony has a set of rules that limit the same way both consecutive octaves and unison.
Lovely bit of pointless pedantry there! I think these experienced mathematicians know that, and given there's a piano in the background....
Nicely done. I’m sure I would have puzzled over this a long time and I’m not sure I would have reached that answer. Thank you.
This is one of the more elegant, simple, and supremely interesting math/physics facts I've ever seen
The base of your Tuning Fork "Round- vs Square-base" does different Resonance while touching the Table. The peak at the Second Frequencies on the square base caused by the Shape of the base.
You see similar effects watching Resonance experiments with Different Material/Particles and different Resonance plates (Round vs Square). It's all about Creating an interference pattern in a mechanical resonance with a different Material shape.
The force and the response of the Square structure form are in phase with one another, creating different resonance patterns by the form, and the energy in the vibration increases.
5:37 that was a Parker wave of a graph
That's super cool! I've always wondered why there was an octave difference
The Hz was reading as low by ~1 because you were in a room that was slightly hotter than the standardization temperature, causing thermal expansion of the metal tuning forks, lengthening them and thus lowering the frequency.
Very impressive. A new bit of information.
Brilliant is the new Audible. Its everywhere!!
Brilliant!
So Audible is now inaudible...
What is the app used on his phone?
Overtones!
Elements of this idea actually show up in Adam Neely's "SUBHARMONIC Music" video, so that may make for an interesting piece of further reading.
Parker-green at 2:35
Parker Color Coding
5:40 Yeah dude it's not going to annoy your musical friends because any decent musician already knows about the overtone series. It was a very nice demonstration of where the higher octave comes from. If you had a spectrometer that showed more than one frequency you would actually be able to see both the frequencies resonating at the same time although the higher octave would be significantly quieter. On most instruments it's common when one note is played for several different multiples of the fundamental to resonate as well. Those are called overtones and are exactly what you just demonstrated. The ear focuses on on the fundamental, but it hears the rest as well. It's what makes a piano playing one note sound different from a guitar or a French horn playing the same note.
Musicians typically won't be surprised you get multiple notes from one fork, as that is the principle of the harmonic series. A vibrating instrument causes notes an octave higher (double the frequency), an octave and a fifth (triple the frequency), two octaves (quadruple) etc. This is how a trumpet is able to play all the notes even though it only has 3 buttons.
WHERES THE MATT AND HUGH PLAY WITH A THING AND THEN DO SOME MATHS INTRO?
*then do some working out
I was thinking that they really didn't do enough working out to merit the other intro.
5:45 "How can the one tuning fork be vibrating at 2 different notes at the same time?" The same way you are able to speak in a voice that's not a singular sine wave. I mean look at the harmonics on the app. It's already vibrating at lots of prominent frequencies.
Good stuff, as always :)
There's some really cool stuff you do with the harmonic series using Fourier transforms and spectrograms which you can do with the human voice. Bit harder to do with other instruments because of the way they're tuned- that's really interesting as well.
Forgive me if this is basic and mentioned elsewhere but rotate an oscillating tuning fork around its vertical axis and hear the nodes and antinodes of waves in and out of phase. Great things tuning forks and they have many interesting properties and uses that are not all musical.
Regarding the thee-sided coin problem, I will be fascinated to learn that once the optimal ratio is discovered, how it makes sense mathematically (since it appears it will fit neither of the proposed hypotheses).
What is happening is that you are creating longitudinal waves down the mast as the forks are vibrating in and out, the mast is moving up and down, when you press the butt of the mast against a flat surface it is essentially trading a sustained ring for a shorter amplified ring by transferring the longitudinal waves into the flat surface of the table, like a speaker driver
‘I never knew you were so good at playing the table”. Please never stop being funny.
I'm not sure if you could annoy the musician friends by saying there's two notes, in musical terms it's the same note in two different octaves, and the original note already contains the harmonic overtone frequency, but the original frequency overpowers it. The demonstration actually shows it pretty nicely where you can see the original frequency and the octave as the strong peaks but different levels when you touch. Also a fun thing to do is touching the ball end of the fork to your skull. Internal loudspeakers.
If you haven't read it yet, "Fundamentals of Musical Acoustics" by Arthur H. Benade was a mindblower for me. Also, how incredible is it that we have excellent oscilloscopes available as free apps on our phones?!? when i was in college, a used device that could come close to this would cost me a couple thousand dollars.
The waveform at the handle wouldn't actually be a sinusoid. It would be more like |sin(wt)|. The motion of the handle is akin to the signal coming from a full-wave rectifier, which is why its fundamental frequency is twice that of the tines, but spectrally it's actually quite different.
That last demonstration is a cool example of when the subharmonic series actually does appear naturally! You're getting integer divisions of your fundamental instead of multiples.
this can be done with ordinary forks as long as the style of the fork accidentally has a nice tone. It's a cute trick. Pluck a couple of the fork tines to get clear tone holding the fork just off the table. Hold fingers in a pinch near the fork then put your fingers into a glass while setting the end of the fork on the table just as your fingers go into the glass etc. Balancing the fork on a finger and allowing the fork end to barely touch the table will produce a buzz too.
Thats a logical explanation. I never noticed that. Went back to check it with my tuning fork and surprisingly it doesn't work. The top part of the fork and the "handle" at the bottom vibrate at exactly the same frequency. (even though I'm a musician, I know how to distinguish between different octaves). Now I'm confused. Can anyone explain this?
(I have a smaller tuning fork, similar to the one Hugh showed in the beginning, tuned to 440 Hz, also the "branches" of the fork are more cylinder shaped, not rectangular like in this demonstration.)
Same here, using a small fork with rectangular branches and cylindrical base. 440 Hz from fork and resonance surface.
Same to me with the classic 440Hz small "cylindrical" fork, same octave to the ear and to the app.
I tried it too. I never knew the effect happened because my fork produces the same frequency. I double checked it with a tuner, and it is in the same octave, A4. Perhaps what we hear in our ear is the second harmonic and the fork is designed to supress the first.
I recall you using that app for the fidget spinner video, could you tell us what it's called?
an analogous effect was observed when electro boom and the slow mo guys filmed a tesla cool at a million frames per second- the arcs were strobing at twice the resonant frequency of the tesla coil because both the positive and negative peaks correspond to luminosity peaks in the plasma
How about a standing wave in the tuning forks stem? The stem oscillates up and down and should be tuned in length. I'm thinking standing wave ratio, like an RF antenna. Also, holding the fork introduces a node pretty much at the center (half way) of an already vibrating element. I don't have a tuning fork, but I wouldn't be surprised if by changing the way the fork is held, different results occur. This would inevitably change the ratio between the fundamental and the first harmonic. Maybe holding the fork higher or lower on the stem and/or rotating the stem 90° might yield interesting results.
Nice one!
I thought the conclusion would be that as the first tunning fork has a square shape, the vibrations don't flow on a spiral down the fork, making the tone go up an octave when the opposite vibrations combine at the base. With the second fork, the vibrations get to the higher octave at first, but then find their way up and down the fork on the same direction and flowing all in one, keeping the intended frecuency. Just as cilinders can take up more weight than a cube, as the force flows and gets a better distribution.
Maybe compare two rounded forks with different bases, to see if that's what's making the vibrations flow steadly?
You should do a follow up with weighted tuning forks!!
Fab, reminds me of something I discovered years ago and baffled a few people with:
Why, if your domestic electricity supply is 50Hz (UK), do your lights flicker at 100Hz?
Good luck 😉
That was amazing! Thanks!
I expected a little aside about how air conduction is stronger than bone conduction for humans... so that if you hold the butt of the tuning fork to the bone just behind the ear and wait for the sound to die off, then take it off and listen to the fork "normally", you should be able to hear the note again... though I wonder if the notes also differ by an octave!
Fascinating! Can you also explain why the ring when you hit the tuning fork is higher than the resonant frequency? For example, my 440Hz fork rings at what seems to be 6x higher (2640Hz, or two octaves and a fifth higher).
Hmm, my tuning fork doesn't have that effect it seems. Is that possible? It has an small scoop on the bottom of it, maybe that's compensating the octave change?
Arthur Weasley finally made it big in the muggle world. So proud of him, way to go man.
Hard boundary for internal wave reflection as opposed to soft boundary emphasizes the harmonic. The guitar harmonic selection comment is misleading. Finger positions on a guitar select the primary resonance length and tension, and likewise shift all resonances accordingly as opposed to selecting them.
3:42 Oh God, the little arrows disappear and reappear again, I will not be able to sleep tonight
I was not able to reproduce part 1 of this vid: the double frequency when put on the table vertically. The explanation seems logical, but the main frequency stayed the same (i.e. did not double). In the demo, I don't see a real frequency peak in the analyser graph. A pitty because it would have been amazing effect.
Guys, if you ask a musician they will tell you that it is the same note because it IS the same note. What you're doing is the same as if you fretted a stringed instrument at the half way point. You would get the same note different octave. Now can you isolate the overtone series based on the surface you use to amplify the tuning fork?
As a musician, I'm actually not that surprised that a tuning fork can play different frequencies in different situations. I would have been surprised however, if it wasn't a note which differs by and octave, a fifth or a fourth.
Sound waves tend to act strangely, and usually when you hear a note, you're actually hearing many frequencies at once, the higher being a multiple (or near a multiple) of the lowest (that's called the harmonic series). The first intervals in the harmonic series are an octave, then a fifth, then a fourth (an octave above the first one) which is why I expected these changes.
it looked to be a lot more than 2 frequencies...when you used the spectrum analyser, you could see fundamental, 2nd order, and some of the higher order harmonics as well
That is pretty darn fantastic ... The whole relation octave / double the frequency blew my tiny mind !
Cheers!
Which spectrum analyzer app are you using?
Congrats on committing to the aerodynamic look! I'll be there soon, myself. But still kidding myself that it's not quite thin enough yet...
The musical friends who say both notes are the same are still correct, because it is exactly an octave jump, which in music is the same named note, example A4 (440hz) to A5 (880hz) is still called A, even though they are in actave apart
I love this!
I have a tuning fork that is cylindrical, so it oscillates rotationally, meaning when I put it against a resonant surface the same frequency is produced, not double!
as a pseudo-musician it doesn't surprise me to get different octaves out of one string. not just by pressing them on the frets, but by inducing a standing wave in the string, so effectively it only swings on half its length. or a third... whatever fret you lightly press on it before letting go...
2 old men hit forks against their hands and then apply them to the table to listen to the sounds.
For the fear of being too nerdy about it, but I think I might be in the right place for this, that is the same note. If you go an integer number of octaves from a note, you get the same note, albeit in a different octave.
i seem to recall i've heard a word you can stick in front of the word "note" which would make the claim correct. (the same way it would make it correct to switch out the word "note" for "pitch").
can you tell me what that is?
intuitively i would go for "exact note", but i may be completely wrong.
maybe there isn't even such an expression at all and i'm just misremembering something, or someone told me inaccurate information...
I think I have the solution, and I think you’re wrong. The higher pitch sound occurs when the teeth of the tuning fork are perfectly parallel, the more they are bent (inwards or outwards), the less you hear the high pitch tone. Once the amplitude of the vibration is smaller than the bending-angle, you don’t have the high pitch tone at all. For better understanding, picture a tuning fork that is bent open 180 degrees.
It would be interesting to know what would happen, if you put the fork down on the table at different angles instead of always at 90°.
Shouldn't both frequencies crossfade the more you lower the angle?
I initially thought it was going to be something to do with the harmonic series, as the surface of the table isn't moving in a perfect sine wave like the fork
Could the property of a tuning fork have anything to do with the effect of the double slit experiment?
Go Mirko!
Adam Neely - The undertone series!
It's funny because at least in my speakers the mics are picking up more of the overtones, it's hard to hear the actual fundamental of the tuning fork unless it's placed on the table.
Very interesting! I always wanted to buy tuning forks but didn't know how to use them. Where can I buy them and what's the name of that app?
Matt's hair is resisting baldness...? It's come back. Well done Matt's hair, this is impressive.
Us musicians are interested in whether you can highlight other positions in the harmonic series! We know you can get the octave, but can you highlight the fifth or even the third?
It's all a matter of ratios! In the same sense of cutting a string into smaller bits to get the harmonic series, you'd just have to make it vibrate faster!
BunniBuu Right! But I'm wondering whether one can one get a tuning fork to highlight those ratios.
I'm not sure about the fifth or the third, but if Hugh can accurately get the tuning fork to vibrate on the table every third cycle, he'd have a fifth DOWN from the original pitch of the fork.
My brother would like this, not because he likes math, but because he likes music... although, now that I think about it, one of his roommates likes math... (On a different 'note,' I have found that many two-pronged forks, like meat forks or toaster tongs, will act in the same way as a tuning fork, making a tiny tone when struck... just thought some people might find that interesting. [Watch now a bunch of people will be striking their forks to see if they vibrate. Please be careful with the meat forks!])
It's twice as fast because the table is receiving the vibrations of both prongs in that position whereas in the air the whole thing has the same.
This was great, but I was SO disappointed that the video ended before we heard the /3 pitch :( Did he manage to produce it?
As a munition I feel the need to say that a musician saying it's the same note WOULD be right, because it's the same note an octave higher. Which in music is often considered the same thing. Still cool and science-y but to a musician it is the same note.
maybe its just the two fork tines canceling in the air air but when you put it on the table they combine through the base and double the frequency?
Interesting that the camera microphone only picked up the fifth harmonic at the beginning of the video (until they touched the tuning forks to the table)!
3:31 I’m trying to figure out if he just claimed that centripetal force and centrifugal force are interchangeable terms.
Centripetal force is what he’s talking about. Not centrifugal force. They’re not the same thing.
how does that simulation work? I mean, if "we" are trying to determine proper ratio for some distribution, what goes into program for expected results?
Take a violin string and just touch it at half was bewegen fixed points, you will get a perfect octave up. Same on violas and cellos. Musicians call this flacholet (at least in Germany)
What’s the best iPhone app for trying this out? I’ve got a few but none of them show the dominant frequency in large text as in the video and I like that feature :)
Funnily, my tuning fork doesn't do this... Neither do I hear different pitches (and my hearing is very good), nor does the app on my phone, it is both 440 Hz...
which app?
Matt’s hair is BACK!
_Matt & Hugh Play With a Thing, and Then Do Some Working Out_
3:58 That's a really nice photo of Albert Einstein in the background!
I am a musician and I can tell when a note is an octave higher. I think the musicians he has asked are referring to the pitch class of the note, not the sounding octave...
I feel like Hunt is mixing up notes and frequencies a little bit.
Could you have a tuning fork with 3 tongs? And would it then create a pitch other than an octave up when placed on the table?
I dont mean to sound like a dick or a genius or anything but it just made sense it would be double. 2 into 1 with the same output. It made me think back to Learning about waves with those really long springs they had in physics in high school and gave me an idea...
Suppose you were to attach two springs to one and had one friend on the end of the one, holding it still. Then you and another friend, or just you if you could do it easily, grab the two ends of the double end. Hold them far enough apart so they wont physically interfere with each other and set them in wave motion, trying to maintain synchronicity. The amplitude in the one spring should be roughly double the height of the amplitude of the two springs. Would that work? Then you could actually see the effect on a much larger scale.
When the note was being displayed there where two side bands next to the main note. Why are ther there?
Is there a difference between puttin the fork on a table and have it fixed to resonance box?
What if you have two forks of same frequency, and then touch their stems together?
Depending on the phase, they might either cancel out or double, right?
I love the pen(i almost said where's the brown paper??)
To all you musicians out there, this is really only half the story. The frequency doubling is on top of the original frequency of the tuning fork. So instead what you hear is a change in timbre and not pitch, as the new frequency is in the harmonic series.
Rest easy.