🚀 go-pugleaf

Hi folks,

OK, can someone address the timing issue here?  When exactly does the effect
of sonoluminescence occur during the cavitation cycle?  How well is that
timing really known (and by what methods)? 


From reference list Steven Jones provided I have this short quote:

> D.F. Gaitan, L.A. Crum, C.C. Church, R.A. Roy,
> "Sonoluminescence and bubble dynamics for a single, stable, cavitation
> bubble," J. Acoust. Soc. Am. 91(6): 3166 (June 1992)
> 
>   "High-amplitude radial pulsations of a single gas bubble in several 
> glycerine and water mixtures have been observed in an acoustic stationary
> wave system at acoustic pressure amplitudes on the order of 150 kPa (1.5
> atm) at 21-25 kHz.  Sonoluminescence (SL), a phenomenon generally attributed
> to the high temperatures generated during the collapse of cavitation bubbles,
                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> was observed as short light pulses occurring once every acoustic period." 
>
>   "Despite the extensive amount of research done on both acoustic cavitation
> and SL, many important questions relating to the nature and dynamics of
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> these phenomena remain unanswered."
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


From Dale Bass in <1993Jan5.180115.17549@murdoch.acc.Virginia.EDU> I have:

>  ... in stable cavitation in acoustical fields, the sonoluminescence occurs
> shortly after the bubble reaches maximum radius (i.e. just as the bubble
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> starts its inward cycle.  Keep in mind that in stable sonoluminescence,
> the bubble itself does not completely collapse.).  This implies that the
> sonoluminescence is mediated by a strong shock in the vapor itself (See
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Barber and Putterman PRL: 69:3839 (1992) among others), ...


Sooo... Am I trying vainly to solve a pretty-much-fully-understood problem?

If it's rock solid that the luminescent pulse occurs in the central void just
as the surface of the a vapor-filled bubble twitches inward, then what's to
solve?  It would indeed have to be a vapor-filled bubble (not void), and it
would indeed _have_ to be a shock wave, not a surface implosion.

So again, has sonoluminiscence _already_ been solved, or not?


				Cheers,
				Terry Bollinger