Re: wave trains

[Roger Haar <haar@PHYSICS.ARIZONA.EDU>]

HI,

        I am not sure why you would say that
a 100 meter long wave train cannot be a single
photon.  If one knows the energy of the photon
very well then the exact time it passes is
poorly known.  Similarly with momentum and
position.

        I am pretty sure that inference
experiments have been done with path difference
of at least a meter and at single photon rates.
Photons can be long.

Thanks
Roger Haar

Ludwik Kowalski wrote:
> The "wave train" of a laser is often very long, for example,
> 100 meters or more. Obviously, it can not be identified
> with a single photon from one atomic transition. It is a
> sequence of photons matching each other perfectly.
>
> Suppose that the train is made from 1000 photons and
> that one of them, from somewhere in the middle, happens
> to ionize an atom. What happens to the train? Is it divided
> into two uncorrelated trains of shorter length?
> Ludwik Kowalski