Comparing lists

[Steven D'Aprano]

On Sun, 16 Oct 2005 19:42:11 +0200, Christian Stapfer wrote:

> Pauli's prediction of
> the existence of the neutrino is another. It took
> experimentalists a great deal of time and patience
> (about 20 years, I am told) until they could finally
> muster something amounting to "experimental proof"
> of Pauli's conjecture.

Pauli's conjecture was the result of experimental evidence that was
completely inexplicable according to the theory of the day: energy and
spin was disappearing from certain nuclear reactions. This was an
experimental result that needed to be explained, and Pauli's solution was
to invent an invisible particle that carried that energy and spin away.

(When I put it like that, it sounds stupid, but in fact it was an elegant
and powerful answer to the problem.)

The neutrino wasn't something that Pauli invented from theoretical first
principles. It came out of hard experimental results.

Physics of the last half century is littered with the half-forgotten
corpses of theoretical particles that never eventuated: gravitinos,
photinos, tachyons, rishons, flavons, hypercolor pre-quarks, axions,
squarks, shadow matter, white holes, and so on ad nauseum.

Neutrinos and quarks are exceptional in that experimental predictions of
their existence were correct, and I maintain that is because (unlike all
of the above) they were postulated to explain solid experimental results,
not just to satisfy some theoretical itch.

So yet again, your triumph of theory is actually a victory for experiment.


-- 
Steven.