phonons

hey didya know that just like the particle form of light is a photon, the
particle form of acoustic waves is the phonon? As far as I can tell poking
around websites I really cannot understand, its only really applicable to
extremely high frequency acoustic energy passing through solids and also
something to do with superconductivity, but its cool nonetheless to think
there might be a quantum theory of sound! Maybe John S. or some other
mathematically literate member here might know if there is any relevance at
all to audible sound??

Dante

My understanding is that when you do granular synthesis, you're using
phonons, which are the same thing as wavelets which are the same thing as
Gabor logons. I think that wavelet synthesis was developed from taking the
quantum mechanics concept of wave/particle duality and applying it to music.

- Jeff

--- In metatuning@y..., "Dante Rosati" <dante.interport@r...> wrote:

> hey didya know that just like the particle form of light is a
photon, the
> particle form of acoustic waves is the phonon?

yes, this was a source of great controversy on the tuning list a
while back (was it in the Mills days), the argument involving myself
and Gary Morrison. the fact is that you need quantum mechanics to
understand what the relationship is between the photon and light
waves. once you've grasped that, the situation with sound is really
no different.

> As far as I can tell poking
> around websites I really cannot understand, its only really
applicable to
> extremely high frequency acoustic energy passing through solids and
also
> something to do with superconductivity, but its cool nonetheless to
think
> there might be a quantum theory of sound! Maybe John S. or some
other
> mathematically literate member here might know if there is any
relevance at
> all to audible sound??

yes, quantum mechanics is applicable to all phenomena in the
universe, except we don't exactly know how to apply it in regions of
extremely high gravity (like the big bang).

anyway, study quantum mechanics (preferably as the third or fourth
year of a physics degree course), get a good grade, and you'll be
prepared to grasp phonons. popular media accounts really won't get
you anywhere.

--- In metatuning@y..., "X. J. Scott" <xjscott@e...> wrote:

> My understanding is that when you do granular synthesis, you're
using
> phonons,

not at all!

> which are the same thing as wavelets

wavelets are an alternate basis for decomposing functions -- this is
mathematical, not physical.

> which are the same thing as
> Gabor logons.

never heard of those.

> I think that wavelet synthesis was developed from taking the
> quantum mechanics concept of wave/particle duality and applying it
>to music.

nope. the *classical* uncertainty principle, which has been discussed
on the tuning list, predates quantum mechanics by a long time,
underlies fourier analysis, and is what motivated wavelet theory as
well.

that said, it's true that the mathematics of all these things is
closely related. but no, granular synthesis does not deal directly
with phonons.

> > hey didya know that just like the particle form of light is a
> photon, the
> > particle form of acoustic waves is the phonon?
>
> yes, this was a source of great controversy on the tuning list a
> while back (was it in the Mills days), the argument involving myself
> and Gary Morrison. the fact is that you need quantum mechanics to
> understand what the relationship is between the photon and light
> waves. once you've grasped that, the situation with sound is really
> no different.

I'm sure, but what I was wondering is if there are any applications of this
to musical issues or tuning.

> anyway, study quantum mechanics (preferably as the third or fourth
> year of a physics degree course), get a good grade, and you'll be
> prepared to grasp phonons. popular media accounts really won't get
> you anywhere.

I'd love to, but there aren't enough hours in the day as it is!

Dante

--- In metatuning@y..., "Dante Rosati" <dante.interport@r...> wrote:

> I'm sure, but what I was wondering is if there are any applications
of this
> to musical issues or tuning.

classical physics works fine for these issues. quantum mechanics is
useful in realms where the laws of classical physics break down.
maybe someday it will be useful in the understanding of the workings
of the human brain, including in the perception of music. but this is
all speculation at this point . . .

on 11/22/02 3:47 PM, wallyesterpaulrus wrote:

>> which are the same thing as
>> Gabor logons.
>
> never heard of those.

From Denis Gabor's work.

A Gabor logon is the smallest unit of information in a hologram.

Some research back around 1987 showed that it was also the smallest unit of
information in a Monkey's brain.

I used Gabor logons to model subatomic objects when I resolved the GUFT
about 15 years ago.

- Jeff

<snip> Maybe John S. or some other
> mathematically literate member here might know if there is any > relevance at all to audible sound??
>
> Dante

All I know about phonons is that they are a way to characterize vibrations of a lattice. Imagine, for the sake of simplicity, that we have a crystal made up of atoms in a cubic configuration. These atoms can be visualized (imprecisely, but close enough for our purposes) as an infinite 3 dimensional array of balls connected by springs (six springs per atom, one to connect to each neighbor). The springs represent the atomic forces between the atoms. Then you can imagine that a small vibration of one of the atoms could be transferred to each of it's neighbors, and so on down the line. You can get periodic waves, like a vibrating crystal (think piezo electric buzzer) or a soliton, that is an isolated wave pulse (and probably other wave types I haven't thoughta).

It turns out that the vibrations in a crystaline lattice (or any continuous almost incompressible media) can be modelled as a quantum system. That means that the energy of any particular frequency of vibration take on only a certain set of discrete values, as if your amp could put out, say, only 11 distinct volumes. Because of the quantum mechanical nature of phonons, they can be viewed as particles or waves. When two waves interact, it can be viewed as the creation and/or destruction of sound "particles", phonons. These "particles" have a constant momentum (mass times velocity) because the velocity is fixed at the velocity of sound in the medium, and the energy is fixed, due to the discrete values of energy.

So sound waves in an almost incompressible medium can be modelled as a kind of particle. That is the extent of my knowledge. Some of it may be a little off, but it is essentially correct (I hope!) So if you had **really** sensitive hearing, perhaps you could hear the discrete volume levels as you pumped up the exitation of a crystal oscillator.

John Starrett