Re: Quantum Computers [was Read any good books lately?]

Bryan Moss (bryan.moss@dial.pipex.com)
Wed, 18 Aug 1999 19:54:39 +0100

John K Clark wrote:

> >The most plausible alternative, imho, would be to assume that the
> >wavefunction is not 'real'
>
> The wavefunction is an abstraction that humans find useful in thinking
> about things very small, it's as real as the lines of longitude and
> latitude. Particles are real, certainly measurements are.

As I said, "the wavefunction ... is no less real than anything else."

> >and is a product of limited knowledge.
>
> Bell's inequality has been experimentally proven to be false and that
> pretty much torpedoes the hidden variable idea, certainly the loopholes
> are very small and they seem to keep shrinking even more every year.

Did I mention hidden variables? I guess 'limited knowledge' implies hidden variables, but it doesn't have to, no sir.

> Anyway, how could you be proven wrong, all good scientific theories need a
> way to do that.

For now it's open to interpretation. My preference, given the choice, would be MWI over observer collapse. But you may as well just run with neither until you're given a reason to think otherwise.

> If you don't see interference bands many worlds is dead and Copenhagen
> is possibly right, if you do see interference bands Copenhagen is dead and
> many worlds is probably correct.
>
> There are only two possible outcomes, what's your prediction, do we get
> interference bands or not, how do you place your bet?

I may have missed something but it seems to me that Deutsch's experiment would only disprove observer collapse, which was silly to start with.

BM