1994-03-30 - Quantum Physics

Header Data

From: “W. Kinney” <kinney@bogart.Colorado.EDU>
To: cypherpunks@toad.com
Message Hash: 99e845b933be9ffe5d0bdc9b554f6e23c8f9926ec8e7b39f928d90f3a7aa742a
Message ID: <9403302308.AA27276@bogart.Colorado.EDU>
Reply To: N/A
UTC Datetime: 1994-03-30 23:08:57 UTC
Raw Date: Wed, 30 Mar 94 15:08:57 PST

Raw message

From: "W. Kinney" <kinney@bogart.Colorado.EDU>
Date: Wed, 30 Mar 94 15:08:57 PST
To: cypherpunks@toad.com
Subject: Quantum Physics
Message-ID: <9403302308.AA27276@bogart.Colorado.EDU>
MIME-Version: 1.0
Content-Type: text/plain




Jim Choate is making a lot of strange statements, but I'm picking this
one:

> First off, EM fields are NOT QM. 

Sure they are, in Quantum Electrodynamics, which is the quantum-mechanical
theory of electromagnetism.

> They do have some characteristics which
> 'bleed' over form the Quark level. 

Quarks have nothing whatsoever to do with electromagnetic fields, except
that they carry charge.

>Also since EM fields are made of
> hardons [sic ;-)] 

No. Protons and neutrons are hadrons. Hadron comes from the (Greek?) word
for "heavy", lepton from "light". The distinction you're trying to make
here is that matter fields are _fermions_, with spins an integral multiple
of 1/2, and gauge fields (like photons) are bosons, with integral spin. 
Both hadrons and leptons are fermions.

>and not leptons (which an electron is) may blow a hole in this
> approach since leptons do not follow the same sort of charge conservation
> rules as hadrons.

Charge conservation applies to everybody. Hadrons, leptons, everybody. Even 
your mother. Perhaps you're thinking of the fact that bosons and fermions
obey different spin-statistics rules.

>
> As to infinite precision and its non-presence....Beeep....wrong answer...
>
> Electrons change state in zero time, this implies at least some form o f
> infinite precision (otherwise how does the system know the difference between
> zero and some small-o value?). I suspect this is another error based on
> the implied (and incorrect) implication in this line of discussion that
> hadrons and leptons use the same rules.

What?

Not that this is the appropriate list for particle physics, but this kind
of semi-mystical expounding on how quantum mechanics forces you to rethink
all the rules is better science fiction than science. QM _does_ include
some spooky things, but by and large they are subtle and limited -- for
instance, the "faster than light communication" implied by spin-polarization
measurements cannot be used to transmit information. It's a purely 
statistical effect, and it does _not_ violate relativity.

Nothing I've ever heard of in QM invalidates assumptions one might make
about computability or the properties Turing machines. Stuff like Roger
Penrose comes up with in _The Emperor's New Mind_ is speculation, and he
clearly labeled it as such in his book. Don't take it too seriously.


                                -- Will








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