Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Is Particle Physics At Risk of Becoming Tautological?



Hi all-
Ed Schweber attempts to ask a meaningful question when he asks:
**********************************************************************
Let my ask a question that I have not completely formulated myself but
which I occasionally wonder about.

In classical physics, the results of an experiment can be interpreted
without referring back to the theory being tested. We can measure mass and
velocity in a collision and test momentum conservation without having to
assume momentum conservation as part of the data manipulation. Anything else
would be circular reasoning.

But the mass of a neutrino is not determined that directly. When we start
talking about transitions between particles we are making particle theory
part of our data analysis.

Is particle theory becoming a logically consistent but
self-referential theory that is losing direct contact with the physical
world in the manner of various branches of mathematics?
******************************
But there is really not much connection between the penultimate and
final paragraphs. Apparently Ed is using "particle theory" as an alias for that
part of weak-interaction theory that deals with neutrinos. So I can only understand
the question as asking "is there really a 'particle' in nature that corresponds
to the concept 'neutrino'?". On one level, I thought that Reines and Cowan
answered that question many years ago. On a more fundamental level, I repeat the
question that I have asked on this list on many occasions, "What does one mean
by 'particle', especially in the context of 'wave-particle' duality?" That
question becames even more relevant in the context of interference patterns
generated by atomic beams.
The Weinberg-Salam model of the weak interactions has been tested in
a variety of ways, and has always come through with flying colors. The width
of the Z-boson, for example, imposes strict limits on the number of light
neutrino species; the prediction of the existence of the gauge bosons, Z and W,
is a notable success of the model; and the detection of neutrino generated
muons below 10 km water-equivalent (or upward-going muons from neutrinos that
have passed through the earth) helps confirm our belief in the reality of
neutrinos.
I think that a better question, and one which would set a useful example
for high school students, would be: " Does anybody know a good review article
on particle physics today, especailly one dealing with neutrinos?" One could
then ask an informed question.
Regards,
Jack


"I scored the next great triumph for science myself,
to wit, how the milk gets into the cow. Both of us
had marveled over that mystery a long time. We had
followed the cows around for years - that is, in the
daytime - but had never caught them drinking fluid of
that color."
Mark Twain, Extract from Eve's
Autobiography