[LAD] Audio Levitation

[Dominique Michel]

Le Sat, 4 Jan 2014 20:19:27 +0000,
Fons Adriaensen <fons at linuxaudio.org> a écrit :

> On Sat, Jan 04, 2014 at 06:16:31PM +0100, Dominique Michel wrote:
> 
> > According to that presentation
> > http://www.dalembert.upmc.fr/Oleron2010/docs/Presentations/Oleron-Barriere.pdf
> > it look like Langevin (which is the same than Rayleigh first formula
> > in 1902) apply well when we are long enough from the source, and
> > when we are in its vicinity, Rayleigh (1905) must be applied.
> 
> Interesting, thanks for the pointer. And it closes the circle... 
> 
> The first slide is a quote from one of Beyer's papers:
>  
>   "It might be said that radiation pressure is a phenomenon that the
>    observer thinks he understands — for short intervals, and only
>    every now and then”
> 
> I remember reading the paper that comes from a very long time ago,
> and that was what inspired my remark about radiation pressure being
> one of the more elusive topics in acoustics !

And classical physics is even worst. In Einstein formula e=mc^2, the
only term for which we have a definition is c...

For e, it is no definition, only equations which are not definitions,
and this is the same issue with m=e/c^2, which is maybe the less
obvious equation of all equations.

Ciao,
Dominique
> 
> Ciao,
>