archiv~1: Re: SETI Quantum Communications.

Re: SETI Quantum Communications.

Wayne Shanks ( )
Tue, 03 Nov 1998 22:45:24 -0500 wrote:
> In a message dated 11/2/98 10:57:19 PM Eastern Standard Time, MAILER-
> writes:
> >
> > In a message dated 11/2/98 2:46:35 PM Eastern Standard Time,
> > writes:
> >
> > > To summarise, even if you have a member of the twin pair, your
> measurement
> > > results don't reveal that there is another twin somewhere else - only
> > > comparison of measurements on both show that there was some 'link'. And
> > > this is the basic reason why you can't use quantum teleportation to send
> > > information FTL, as I see it.
> Link means link. Lots of potential there. With some kind of control over the
> link, you have FTL linking. Maybe not practical, but the glimmer of a
> possibility. How about this:
> Entwined particals, say photons, are sent left and right. All the left ones
> are up spin. All the right ones are down spin. One thousand miles to the
> left,
> the photons are read. To transmit info to the right, the left one decomposes
> the spin. Thereby when the photons get to the right one, they know the spin
> has been read,

There is no way to know if one member of an entangled pair has been
measured, thus no bit of info.

You can't communicate at FTL speeds. IF you could then you could
violate causality.

It is not a matter of being clever, with quantum mechanics as we know
it, you can't have instantaneous information transfer. The interesting
thing about QM and all this particle entanglement stuff is that
something is being transmitted, but it is not that is
an odd concept.

Maby it is a half bit :-)

>so a bit of info has been transmitted by the left.
> Of course this wont work because of ..... whatever. But something might.

Ther is no reason to believe that enything can work.... We can always
hope for something new, but Quantum mechanics forbids you to be able to
send a message at FTL speeds. It is not a matter of hope. Quantum
mechanics forbids hope for such a thing.

But of course nobody said that QM is the last word.

Wayne S

> sincerely,
> John Marcus.