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Posted

By Lothar Cremer - who has read this book?

I'm considering buying it to gather as much info as I can to prepare an informal lecture at my subatomic physics "bunker" building. I'm currently not sure if I can find interesting enough information for such an occasion.

For example, simply describing it as a vibrating plate with a particular contour shape that imposes limit conditions, which in turns produces sounds that are combinations of the Chladni modes - wouldn't be interesting enough for these physics buffs. Nor would a tentative exhaustive list of all the roles of the violin's components in the transmission of sound, cut it. I mean, both of these would be part of it, but the talk wouldn't be focused on them. They'd be a good introduction.

What I need is an interesting basis for this talk - if there's a special topic in violin physics that's still unresolved (I'm thinking about the open question as to whether there is still lots of room for sound improvement for this instrument), that still raises interest piquing questions.

These informal lectures last 30 minutes. They are the prelude to free pizza and soft drinks for everyone - that should give you an idea of their relaxed nature, which in turns easily allows for light-spirited remarks, from both the lecturer and the audience!

Posted

About Chladni modes:

Remember the modes of vibration for a rope fixed at one end (stationary oscillations)? Mode 'n' has 'n-1' nodes (not counting the extremeties). Each of these modes have a unique associated frequency. If you vibrate at frequencies other than those specific ones, you get a combination of many, if not all modes.

The Chladni patterns is the same idea, but applied to the violin-shaped top and back pieces (and therefore essentially in 2D).

Look at pretty pictures of some modes here (the lines you see are the regions where there is very little or no motion - the nodes): http://www.phys.unsw.edu.au/~jw/chladni.html

Posted

MuOn

How about"Violins,Variability,and Quantum Mechanics."? The variability relates to the impossibility of two instruments sounding and behaving the same, even when made by the same maker from the same tree, etc. Quantum mechanics is the answer....This is what makes stringed instruments so wonderful,no? Also, an orchestra section could be viewed as Quanta....Maybe you could bring several violins and have a demo performance to illustrate your these ideas? I hope I have been a little helpful... I love applied physics!

Posted

how about comparing the relative value of modern physics, science technolgy etc in contributing to actual violin making, as opposed to Tradition.

I know that sounds awkward, but there's alot of folks who believe, that for all the hype of modern science that very little actually has been forthcoming.

Maybe that's against your nature to Muon, as a physicist.

I mean it's all very interesting but "where's the beef"

I myself am but a fascinated observer

Posted

I don't think one needs quantum mechanics to explain violins - there is enough in the physical understanding that was available to Helmoltz in his time. Mechanical properties of materials at a "classical" level should be sufficient, without getting into the "nature of the chemical bond."

Cremer's book is not a easy read or an easy do. It is a mathematical engineering (physics, if you will) discussion of the violin. I still find it unsatisfactory as a full explanation of the physics of bows. I have the book, I've had it open and read parts of it. I would not claim to have "read the book," and probably will never live to make that claim.

Still if I had to give a talk (lecture) to a group of physicists or engineers on some violin-related subject I would be sure to work my way through Cremer's "The Physics of the Violin" with enough rigor to feel "safe."

Andy

Posted

The Chladni thing is a 19th C. physics done by Savart and his friend Chladni. The Cremer book is rather dry but has lots info. It didn't serve us professional violin makers much good though. Why buy that book, doesn't the McGill Library have it? I would suggest the topic " Uncertainty Principle in Violin Acoustics". Starting from the bowed string, the harmonic spectrum, the excitation of violin body AT THE BRIDGE (forget about the normal modes of body, they are useless because the violin is excited at the bridge). These published modes shapes are at low freq. No one knows what they are at high frequencies. (1) psycho-acoustics: there are min. freq. difference (uncertainty) that human ear can distinguish two different pitches. Some people claim to have perfect pitch is a borogny. (2) What constitutes good tone? Spectral analyses show that great violins have strong partials in 3 to 5k Hz.

[This message has been edited by David Tseng (edited 02-09-2001).]

[This message has been edited by David Tseng (edited 02-10-2001).]

  • 16 years later...
Posted

It could be interesting to focus on the cause/effect relationship of the Chaldni nodes geometries by focusing on perturbation theory, which is what quantum mechanics does when they actually want to do something useful, since partical /field/wave theory is full of duality/paradox. For instance, violins do have some dimensional ratios that are known to be effective &imply geometry. Remember, a wave is what something does, not what something IS. For example, a wave of water is something water does, not what it is, if there is no wave, water is still water, but if there is no sound there is Nothing, hence the potential is in the capacitance of the materials. Perhaps make a statement that "all insulators are also capacitors"(ie. wood), and frequency is simply a field perturbance related to the capacitance of the materials , find the cause of the effect, which is what physics has never been able to discover with the violin. I am sure that if they attempt to answer this question from this angle they will learn something very valuable about their field.

Posted
42 minutes ago, Pylorius said:

It could be interesting to focus on the cause/effect relationship of the Chaldni nodes geometries by focusing on perturbation theory, which is what quantum mechanics does when they actually want to do something useful, since partical /field/wave theory is full of duality/paradox. For instance, violins do have some dimensional ratios that are known to be effective &imply geometry. Remember, a wave is what something does, not what something IS. For example, a wave of water is something water does, not what it is, if there is no wave, water is still water, but if there is no sound there is Nothing, hence the potential is in the capacitance of the materials. Perhaps make a statement that "all insulators are also capacitors"(ie. wood), and frequency is simply a field perturbance related to the capacitance of the materials , find the cause of the effect, which is what physics has never been able to discover with the violin. I am sure that if they attempt to answer this question from this angle they will learn something very valuable about their field.

You'll have to rephrase this one - it has neither head nor tail. Why would I need "perturbation theory" to study "Chaldni node geoemtries" ??? Surely, you meant "Attractor theory". We have a couple of fine scientists on the forum - I'm sure they'll be happy to explain the finer points.  

Posted
1 hour ago, Pylorius said:

It could be interesting to focus on the cause/effect relationship of the Chaldni nodes geometries by focusing on perturbation theory, which is what quantum mechanics does when they actually want to do something useful, since partical /field/wave theory is full of duality/paradox. For instance, violins do have some dimensional ratios that are known to be effective &imply geometry. Remember, a wave is what something does, not what something IS. For example, a wave of water is something water does, not what it is, if there is no wave, water is still water, but if there is no sound there is Nothing, hence the potential is in the capacitance of the materials. Perhaps make a statement that "all insulators are also capacitors"(ie. wood), and frequency is simply a field perturbance related to the capacitance of the materials , find the cause of the effect, which is what physics has never been able to discover with the violin. I am sure that if they attempt to answer this question from this angle they will learn something very valuable about their field.

Ummmm..........in the absence of sound, air, or any other sound transmitting fluid is still there, just as all the quantum fields (such as EM, Higgs, or whatever) are still there in the absence of anything to interact with.  IMHO, you need a good refresher on electrostatics and electrodynamics alongside and contrasted with acoustics, to understand why you shouldn't mix one with the other while theorizing. :)

Posted

I think you should just discuss string theory. There seems to be a lot that is unresolved about that. 

Or how about discussing and debunking the pseudoscience around Stradivarius violins. People love stories about Stradivarius violins. They will ask questions. They will laugh. 

Posted
7 hours ago, Pylorius said:

It could be interesting to focus on the cause/effect relationship of the Chaldni nodes geometries by focusing on perturbation theory, which is what quantum mechanics does when they actually want to do something useful, since partical /field/wave theory is full of duality/paradox. For instance, violins do have some dimensional ratios that are known to be effective &imply geometry. Remember, a wave is what something does, not what something IS. For example, a wave of water is something water does, not what it is, if there is no wave, water is still water, but if there is no sound there is Nothing, hence the potential is in the capacitance of the materials. Perhaps make a statement that "all insulators are also capacitors"(ie. wood), and frequency is simply a field perturbance related to the capacitance of the materials , find the cause of the effect, which is what physics has never been able to discover with the violin. I am sure that if they attempt to answer this question from this angle they will learn something very valuable about their field.

Yes, it could be very interesting, and it has been. While some of us fiddlemakers are highly interested in theory, a lot of us have come down to "pinning the tail on the donkey".

Posted
On 2/9/2001 at 0:33 PM, Andrew Victor said:

I don't think one needs quantum mechanics to explain violins - there is enough in the physical understanding that was available to Helmoltz in his time. Mechanical properties of materials at a "classical" level should be sufficient, without getting into the "nature of the chemical bond."

Cremer's book is not a easy read or an easy do. It is a mathematical engineering (physics, if you will) discussion of the violin. I still find it unsatisfactory as a full explanation of the physics of bows. I have the book, I've had it open and read parts of it. I would not claim to have "read the book," and probably will never live to make that claim.

Still if I had to give a talk (lecture) to a group of physicists or engineers on some violin-related subject I would be sure to work my way through Cremer's "The Physics of the Violin" with enough rigor to feel "safe."

Andy

I'm sorry I'm a little late but I fully agree. Simple mechanical physics (conservation of mass, momentum, and energy) like Cremer uses is good enough to fully explain everything the violin does.  

  • 4 months later...
Posted
On 2/16/2017 at 11:49 AM, carl stross said:

You'll have to rephrase this one - it has neither head nor tail. Why would I need "perturbation theory" to study "Chaldni node geoemtries" ??? Surely, you meant "Attractor theory". We have a couple of fine scientists on the forum - I'm sure they'll be happy to explain the finer points.  

You will have to think more on my statement, for one, the Chaldni nodes suggest geometry, when the angles of Platonic geometrical shapes are added together the resulting number is also a frequency within an A=432hz framework , so at this intersection Angle of geometric shape and frequency become one and the same. That relationship alone should be enough to pique ones interest, why would a true questioning scientist ingnore such an amazing connection? Another more mundane circumstantial evidence, why do so many videos demonstrating violins for sale have the violin tuned exactly to A=432hz? I have heard generally that this happens, but isn't it a bit strange that they always seem to be in A=432hz.? Is this a big clue into what a modern violin cannot recreate if it's tuned to A=440hz.? If a violin sounds better tuned down for resale, well that's kind of a big Frequency clue isn't it? If you recall, I have been slammed for even mentioning this, yet I continue to find an A=432hz pitch to prevail among the contemporary violin world, I have a large collection of recordings, and only the most horrible modern recordings are in A=440hz. It is absolutely undeniable that this exists and is known quite well among violin dealers right here on the forum! What's the big secret?

Posted
1 hour ago, Pylorius said:

You will have to think more on my statement, for one, the Chaldni nodes suggest geometry, when the angles of Platonic geometrical shapes are added together the resulting number is also a frequency within an A=432hz framework , so at this intersection Angle of geometric shape and frequency become one and the same. That relationship alone should be enough to pique ones interest, why would a true questioning scientist ingnore such an amazing connection? Another more mundane circumstantial evidence, why do so many videos demonstrating violins for sale have the violin tuned exactly to A=432hz? I have heard generally that this happens, but isn't it a bit strange that they always seem to be in A=432hz.? Is this a big clue into what a modern violin cannot recreate if it's tuned to A=440hz.? If a violin sounds better tuned down for resale, well that's kind of a big Frequency clue isn't it? If you recall, I have been slammed for even mentioning this, yet I continue to find an A=432hz pitch to prevail among the contemporary violin world, I have a large collection of recordings, and only the most horrible modern recordings are in A=440hz. It is absolutely undeniable that this exists and is known quite well among violin dealers right here on the forum! What's the big secret?

I really can't contribute much here but some violins feel better tuned slightly lower and some slightly higher. Myself use that the get some indication for adjustments, string angle etc. Nothing "scientific" though, more like quasi-informed guesswork. One thing to notice is that a lot of older players are tuned 437 but play slightly higher - often 1/4 tone higher, makes for good effect and helps one stay ahead of piano or orchestra. Some attack the note from underneath, drift passed the pitch and fall back on it - very effective. Now, given that a violin copes pretty well with 3 octaves and can do 5 with some struggle, what difference do you think 3 Hz can make which might not be easier explained as static load on the instrument ?

Posted

Why not go to the real mystery?  What physics could we be missing?  We know about vibration modes, we know about wood properties and materials properties, we know about cavity resonators.  We can even produce exact physical replicas of any given violin now that we have CT scans.  We have the ability to reproduce near perfect computer simulation of all of these issues at our disposal, yet we don't know how to combine our knowledge of the various phenomena, we haven't even been able to even decide what physical phenomena are truly fundamental so that we know what to model to examine the great violins.  We have 300 year old  violins that are in great demand in the market place but we can't seem to reverse engineer them, so what are we missing?  If you gave me a Ferrari or satellite launch system and an adequate budget, I could reverse engineer that exactly, yet with half pound of wood and some simple steel strings in hand, we flounder while violinists everywhere crave a Strad and we can't seem to come up with anything great repeatedly.  What could we possibly be missing?  And of course we know, that Stradivari was missing it also for much of his output.  Maybe black magic is the only explanation...........

Posted
4 minutes ago, David Beard said:

Caution, Carl.  Pylorius has shown in the past that it is the number 432 that he thinks is special.   It's numerology, not science or music.

Thank you. I'm out of here. :)

Posted

Hi Roger,

Consider that two Strads from the same time don't measure exactly the same.   Even on one classical instrument the two sides won't measure out equally.

As long as we keep looking at old instruments by 'measuring precisely', then we keep seeing in a particular way that hasn't worked all that well.   Before 'reverse' engineering, we must determine what is invariant across many classical examples.   That isn't precise measures!

What is 'invariant' or 'variant through a simple finite range' is somewhat imprecisely executed simple geometry constructions, and simple ratios between parts.

After thoroughly looking at what is invariant across many classical instruments, only then could we meaningfully ask why those choices worked.  And only then are we positioned to 'reverse engineer'.

 

IMO

Posted
36 minutes ago, David Beard said:

Caution, Carl.  Pylorius has shown in the past that it is the number 432 that he thinks is special.   It's numerology, not science or music.

You are incorrect, and I suggest you reread any of the the exchanges I have had, the new agey stuff were all accusations from other Maestronet members...I am not talking about numerology, but Geometry, which is a science, not numerology. For someone who spends so much time using geometric relationships, you should know the difference...

Posted
36 minutes ago, carl stross said:

Thank you. I'm out of here. :)

I suggest you review my previous exchanges, if English is your first language, you will see that I have been attacked at all angles, with mostly logic chopping answers  that address no fine points of the conversation, virtually no consideration, and some of the most shamefull vitriol that I have witnessed on Maestronet...

Posted

Hi David:

You're making my point.  We don't even know what to measure to model, what is invariant across a spectrum of great violins, yet we have something carved from wood, easily picked up by a 10 year old child. It appears to be something only slightly more complicated than a soccer ball.   As Sacconi noted, where are the secrets?  Not in evidence, yet for all the apparent simplicity, we don't know the key ingredients that separate  $100 dollar ebay violins from $10 million del Gesus.  It isn't the cosmetics, the workmanship can be duplicated, the materials properties can be measured, the geometry can be precisely duplicated, material properties can be adjusted to render desired dynamic properties, but we still don't know, as you put it, what is invariant across the great violins.  We produce perhaps a few dozen violins per year that are equivalent to the great ones in tonal qualities, and thousands that have workmanship comparable to the great ones.  If there were a market for 1935 Rolls Royce automobiles, we could produce an exact equivalent, we know all the variables.  For violins, we are either failing to consider and implement some essential physics that we already understand or we need to dig deeper to identify some physical principles that warrant further study before we can discover those invariant properties.

Posted
19 hours ago, Pylorius said:

You will have to think more on my statement, for one, the Chaldni nodes suggest geometry, when the angles of Platonic geometrical shapes are added together the resulting number is also a frequency within an A=432hz framework , so at this intersection Angle of geometric shape and frequency become one and the same. That relationship alone should be enough to pique ones interest, why would a true questioning scientist ingnore such an amazing connection? Another more mundane circumstantial evidence, why do so many videos demonstrating violins for sale have the violin tuned exactly to A=432hz? I have heard generally that this happens, but isn't it a bit strange that they always seem to be in A=432hz.? Is this a big clue into what a modern violin cannot recreate if it's tuned to A=440hz.? If a violin sounds better tuned down for resale, well that's kind of a big Frequency clue isn't it? If you recall, I have been slammed for even mentioning this, yet I continue to find an A=432hz pitch to prevail among the contemporary violin world, I have a large collection of recordings, and only the most horrible modern recordings are in A=440hz. It is absolutely undeniable that this exists and is known quite well among violin dealers right here on the forum! What's the big secret?

Because it's not 432, it's 432.1

It's obvious. I don't know why you can't see it???

 

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