Re: Quantum Computers

John Clark (
Fri, 20 Aug 1999 12:51:33 -0400

Hash: SHA1

Lee Daniel Crocker <> Wrote:

>That's my point: the observer /can't/ tell us anything. Ever.
>The act of doing so violates reversibility. Your "document" is
>part of the state of the observer, and it has to be reversed too

Why? The document does not say which slot the electron went through, thus if many worlds is correct the documents in both universes are identical, the brains have been reversed so they are identical too, and so the two universes will merge and produce interference, if Copenhagen is right they will not.

>That's no different from putting ordinary recording gadgets at the
>slots: the pattern goes away, and we get a simple result.

It is different, the physical state of the recording instruments are different so the universes are different and have not merged and so no interference. Many worlds still gives the correct result and so does Copenhagen, that's why your experiment is just not good enough to decide between the two.

John K Clark

Version: PGP for Personal Privacy 5.5.5

iQA/AwUBN72Hld+WG5eri0QzEQIXSgCfVJHp3/lY5nfpVNhX/8uGoNYfIn4AoLRh dt5wIEtCfVLfcV3QP4AbHXrP