Re: Scientists Bring Light to Full Stop, Hold It, Then Send It on Its Way

Date: Thu Jan 18 2001 - 12:35:30 MST

John Clark writes:
> I'll bet that when the first practical quantum computer is built this technology
> will be part of it.

That does sound pretty amazing. I'm looking forward to reading about it in the
technical journals.

However I have become suspicious about this kind of reporting after all
the fuss over the experiment where light supposedly exited the chamber
before it entered. See the thread from this past summer "FTL on Nature",
starting from
and following the thread links. That was a case of terrible misreporting.

The new experiment sounds somewhat similar except they've turned it
around and are pushing the light wave back at the speed of light, maybe.
I'm guessing that what they are really doing is transforming the light
into excited gas molecules, which they then liberate. Of course that
happens all the time in nature but in this case they must be able to
preserve the phase information, which would be an important advancement,
and as John says could have practical usage in quantum computers as well
as quantum cryptography, perhaps.

BTW I've been trying to work out a new idea for quantum cryptography.
You may have heard of the "Dining Cryptographers Net", a crypto protocol
for anonymous communication. My variant uses photons so I call it the
"Shining Cryptographers Net". It doesn't require pre-shared keys as the
DC Net does. I've been discussing it on Perry Metzger's cryptography
mailing list.


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