Re: PHYS; Quantum Teleportation

Dan Fabulich (
Thu, 11 Dec 1997 15:47:38 -0500

At 11:13 AM 12/11/97 -0800, you wrote:
>If I want to send a message to a receiver 2 things must happen:
>1) I must change something in the receiver.
>2) The receiver must be able to compare that change with something else,
> as the voltage on a wire now compared to what it was a nanosecond ago.
>Quantum Mechanics can do #1 but not #2 , so I have just changed one "random"
>state in the receiver to another. The results are not really random but it
>would sure look that way to the receiver. It's only when the receiver
>compared his results with the records of what I did, and that can only be
>done at the speed of light or less, would it become obvious that what I did
>instantly changed what happened in the distant receiver.

This doesn't necessarily seem true to me... You don't have to compare your
photons against their previous states, but only against the states to which
we had previously agreed. Suppose I tell you that every second I'm going
to send you a photon, and that if the photon has agreed-upon property X you
should interpret it as 0, and if it has property Y you should interpret it
as a 1. This agreement would have to happen subluminally, but what if I
then travelled 4E8 meters away and started up the QT machine? Wouldn't
that be FTL communication?