Re: more teleportation

John Clark (
Sat, 24 Oct 1998 01:27:26 -0400

Hash: SHA1

Hal Finney <> Wrote:

>This notion of instantaneous transmission of "encoded" information
>doesn't strike me as a very good analogy.

It's not a perfect analogy, nothing is, but personally I don't think it's bad.

>For one thing, the "speed" of transmission is potentially more than
>instantaneous. If you insist on thinking of this as transmission of
>information, the problem is that it can go into the past as well. It
>can even go into the past light cone of the "transmitter", which makes
>it faster than "faster than light". Also (or equivalently), there is no well
>defined moment of reception.

Some truth in that, if your receiver is a detector of polarized light then it's not clear if the message was received when you measured the rotation of your polarizing filter or when you determine if the photon I sent you makes it through the filter or not; and you could set the filter even before I sent my message.

>There are enough differences from what we normally mean by the phrase
>that I don't think it is useful to call this phenomenon "transmission of
>information" at all.

It's not faster than light but this phenomenon can transmit information, teleportation can be used to get information out of a system without causing quantum decoherence, that's why those who want to make a quantum computer are interested in it. Something like it has also been used in real world in quantum cryptography to transfer financial information between banks.

John K Clark

Version: PGP for Personal Privacy 5.5.5

iQA/AwUBNjFlPt+WG5eri0QzEQJBLACgppS4U2EEXBMrMfC4+V7gLz339rEAoMdl 1DleZ4oEj2SlaPlCJSa5Xzjr