[LAD] Audio Levitation

[Patrick Shirkey]

On Sun, January 5, 2014 7:19 am, Fons Adriaensen wrote:
> 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 !
>

IIUC there are some people who understand it very well but the application
of their knowledge is considered classified so it's not released into the
public domain if it is even written down anywhere. A bit like RSA
decryption used to be.

The funny thing is that the technology that can be created using this
technique would probably solve the energy crisis if this knowledge was
allowed to be used for civilian purposes like power stations. It would
probably also be useful for deep space exploration. ( Avatar scale not
Hubble scale )

Depends on the fuel used of course. One thing we do know is the humble
pistol crab can generate impulses with the same heat intensity as the
surface of the sun and some salty water. What other exotic mixtures would
allow for is anyones guess.





--
Patrick Shirkey
Boost Hardware Ltd