Re: JP Barlow and Grey Mush

Dejan Vucinic (
Wed, 25 Sep 1996 12:51:36 -0500

>On Tue, 24 Sep 1996, Ira Brodsky wrote:
>> Which leads me to another thought: if at bottom the universe is just grey
>> mush, doesn't this suggest a limit to scientific progress? [He shudders.]
>> How do you control something that exists merely within a range of
>> probabilities?

Assuming we ever hit the bottom (no evidence of such to date), why not move
on to researching the more complex, as opposed to more fundamental? Plenty
of space to grow.

>Well, controlling something random is of course only partially possible,
>unless you can use random correlations to do clever things (like the
>essentially random states of quantum computers interfering with each
>other to produce a real result). I personally think control is overrated,
>as Kelly pointed out it is very much an industrial age word and may not
>be as central in the information or nano age.

>The big question is: can we do something useful with something that
>exists just as probabilities?

Ouch. Every time I see a statement like this I'm painfully reminded how
difficult it is to articulate QM in plain english. But what the heck,
I'll give it another try: it's no good thinking of the Universe *existing*
as probabilities. Quantum mechanics describes not the existence of
reality, but its observed behavior. It's a MODEL, just that. Describing
"quantum world" in terms of "probability" is futile. Quantum world, if
you chose to "believe" in it, is more fundamental than the probability.
The probabilistic nature is not inherent in the MODEL, it's a consequence
of the measurement, by which we obtain information about the workings of
the Universe. You don't describe the more fundamental in terms of the less
fundamental. It would be like trying to explain the q/r model of
electrostatic potential in terms of why things don't fall apart. It's
just the other way around; this way it's a non-question.

(Sheesh, look at that paragraph. No matter how hard one tries, it's
still a formidable didactic puzzle. Many briliaant students have spent
years trying to "understand" QM. What a waste.)

>It seems so; quantum computers and
>statistics are obviously useful.

Yes, we can put it to work. And it doesn't matter whether it's a
complete theory or not, as long as it works (to us experimentalists, at
least :).

>> Perhaps there are some physicists around here who can
>> provide reassuring answers...
>The universe has no obligation to be reassuring.

Beautiful. Straight into my quote-file.