Re: Optical repeaters

[jamesd@echeque.com]

At 07:35 PM 2/19/96 -0800, Timothy C. May wrote:
>By analogy, it is not clear to me that a simple regeneration mechanism,
>with no local observer or recording apparatus, will collapse the wave
>function. Seems to me an experiment may have already been done along these
>lines: separate fibers producing an interference pattern and then these
>inline amps added...if the interference pattern remains, as I would expect,
>then the amps/regenerators did not constitute a "measurement" in QM terms.

An amplification mechanism will usually couple the signal to the vacuum, 
and introduce vacuum noise.   Another way of thinking of vacuum noise 
is that amplification mixes the state of the signal, with the (unknown) 
phase of the universe at infinity.

Of course any statement in words about quantum mechanics is necessarily 
false, so the above statement is a metaphor or parable, rather than literal
truth.
 ---------------------------------------------------------------------
              				|  
We have the right to defend ourselves	|   http://www.jim.com/jamesd/
and our property, because of the kind	|  
of animals that we are. True law	|   James A. Donald
derives from this right, not from the	|  
arbitrary power of the state.		|   jamesd@echeque.com