Re: causation

[Stephen Speicher <stephen@SPEICHER.COM>]

On Tue, 18 Nov 2003, John S. Denker wrote:
> On 11/18/2003 10:38 AM, Ludwik Kowalski wrote:
>  >
>  > What is gained by removing the idea of causality from physics?
>
> I'm quite sure nobody has even suggested removing
> cause-and-effect from physics or from reasoning in
> general.

This statement suggests unfamiliarity with historical as well as
contemporary theorists in both physics and philosophy.  Though
there are certainly earlier philosophical roots, it was Werner
Heisenberg who initially led the charge against causality in
modern times. Heisenberg ends his famous 1927 "uncertainty paper"
with:

   "Physics ought to describe only the correlation of
    observations.  One can express the true state of
    affairs better in this way: Because all experiments are
    subject to the laws of quantum mechanics, and therefore
    to equation (1), it follows that quantum mechanics
    establishes the final failure of causality." [1]

That Heisenberg's campaign against causality met with fairly
quick success is reflected just a few years later, in 1931, in
the mainstream _Science_ journal article by Harvard's P.W.
Bridgman, flaunting the title "The Recent Change of Attitude
toward the Law of Cause and Effect." Bridgman notes:

   "Nearly every educated person, brought up in
    present-day society and under the influence of the
    scientific ideas and spirit which pervade our
    intellectual life, prides himself in the belief that
    nothing happens without there being some cause for it.
    We may briefly characterize this attitude of ours by
    saying that we believe in the law of cause and effect
    or in the causality principle....It is now becoming
    common knowledge that one of the most startling
    developments of the altogether surprising progress of
    physics in the last few years has been a weakening of
    the belief of the physicist, at least, in the validity
    of the causality principle....In fact, a number of the
    younger generation have already achieved this degree of
    emancipation, and the rest of us, by deliberate effort,
    may hope to attain it." [2]

This supposed "emancipation" from cause and effect has echoed
through the ensuing decades, and one regularly finds theorists of
physics and philosophy waving the same banner to this day. Now,
personally, I agree with what John says just below, namely that

> Scientists look for cause-and-effect relationships
> the way prospectors look for valuable mineral deposits.
> The ones who find the most are doing their jobs the
> best ...

This is exactly what most real working physicists do on a daily
basis, and they leave the theorists' notions as to the supposed
demise of cause and effect at the doorstep to their labs. But,
regardless, it is simply not true that "nobody has even suggested
removing cause-and-effect from physics or from reasoning in
general." If only that were so.

[1] Werner Heisenberg, "Uber den anschaulichen Inhalt der
quantenttheoretischen Kinematik und Mechanik," _Zeitchrift fur
Physik_, 43, pp. 172-198, 1927, reprinted in English under the
title "The Physical Content of Quantum Kinematics and Mechanics,"
in "Quantum Theory and Measurement," edited by John Archibald
Wheeler and Wojciech Hubert Zurek, _Princeton University Press_,
1983.

[2] P.W. Bridgman, "The Recent Change of Attitude toward the Law
of Cause and Effect," _Science_, New Series, Vol. 73, No. 1899,
pp. 539-547, May 22, 1931.

--
Stephen
stephen@speicher.com

Ignorance is just a placeholder for knowledge.

Printed using 100% recycled electrons.
-----------------------------------------------------------