Re: [gentoo-user] Question of quantum computer

[Rich Freeman <rich0@gentoo.org>]

On Fri, Apr 3, 2015 at 5:11 PM, Fernando Rodriguez
<frodriguez.developer@outlook.com> wrote:
>
> There's an explanation for uncertainty that makes common sense. Let's say I
> throw you a ball, you can catch it because you take many measurements of it's
> location and your brain tries to predict it's path. But this only works
> because the ball is so massive and the photons that we use to see it are
> massless so the effect of them colliding with the ball is neglible. Imagine if
> the only way you could "see" the ball was by throwing another ball at it and
> seeing where it landed, it would then be nearly impossible to predict it's
> path because everytime you measure it you'll get it of course, so the
> principle of uncertainty would hold even though the ball was really on a well
> defined path.

Well, the quantum mechanic would say that the position of the ball was
indeterminate until it was measured.  The probability of it being in
any particular position is given by some function that agrees with
experiment very well.

The problem is that it is really hard to distinguish that "reality"
from a "reality" where the ball followed a well-defined trajectory the
whole time, and we just don't know what it is until we measure it.

As others have pointed out, the classic quantum mechanics explanation
relies heavily on the concept of an "observer" which is a bit odd.
Should the behavior of a particle depend on whether anybody is
watching it?

>
> If we ever figure this to be wrong it'll probably just obsolete quantum physics
> so instead of deterministic quantum computing we'll have something else.

Absolutely true.  Quantum mechanics could possibly be a theory that
gives the right answer for the wrong reasons.

I'm not knocking it, because it is the best theory we have.  It is
just incredibly unsatisfying as a theory.

-- 
Rich