Re: Quantum question?

[Jack Uretsky <jlu@HEP.ANL.GOV>]

        But you did not confine yourself to a single photon, which was
the challenge.  And, strangely enough, and depending on the measurement,
a single photon is pretty darn close to being an energy eigenstate.
        One can certainly see the interference pattern after many photons
have entered the apparatus, but that is not a measurement on a single
photon.
        It is single photon measurements that one uses to detect particles
such a the neutral pion or the eta.
                                Regards,
                                        Jack

Adam was by constitution and proclivity a scientist; I was the same, and
we loved to call ourselves by that great name...Our first memorable
scientific discovery was the law that water and like fluids run downhill,
not up.
                          Mark Twain, <Extract from Eve's Autobiography>

On Fri, 28 Jan 2000, Roger Haar wrote:

>     I suggest a Michelson interferometer or modern variant.  Even with light
> entering at a low enough rate, there is a finite range of difference in optical
> path lengths in which one observes interference.  One can know the energy of the
> atom photon system and not necessarily know the energy of the photon.   The
> world is not made of things in energy eigenstates
>
> Thanks
> Roger Haar U of AZ
> ************************************************
> Jack Uretsky wrote:
>
> >         Please tell me how to measure the width of a single photon, or,
> > for that matter, its extent in space and time.  What photonic process do
> > you invoke?  What instruments do you use?