Re: Laws and Theories

[Leigh Palmer <palmer@SFU.CA>]

> On Sat, 4 Mar 2000, Raymond A. Rogoway wrote:
>
> > [snip]
> >
> > I'll probably be drummed out of the APA (not APS). I love the work with
> > clients but it ain't a science by any stretch of the imagination.  As
> > for Economics...falls in the same category as used car salemanship and
> > weather prediction.
>
> Ouch!  Just a minute there...Weather prediction has come a long way in the
> past 100 years.  Most of modern meteorology is a science as far as I am
> concerned.

It may be, but it's not an exact science by a long way. Our physicists'
reductionist sympathies tend to make us think that meteorology (and
climatology) *should be* exact sciences, but limitations of computing
power, knowledge of boundary conditions, and the likely chaotic nature
of the as yet unknown equations of motion of the system are enough to
convince me that meteorology will never be more than a black art. You
should live in a place like Vancouver where the weather changes
rapidly (and where there is a scarcity of information about the boundary
conditions in a small adjacent body of water we call the Pacific Ocean)
to get a feel for the potential accuracy of meteorology.

I attended a colloquium on computer modelling in meteorology back in
the early sixties at Cal. The speaker was very enthusiastic about the
promise of the methods which he described to us. At the conclusion of
his talk he took many questions, and he finally took one from one of
the White-Haired Eminences who sat in the front row.

"Excuse me, sir, but you didn't say anything about the accuracy of
your computer weather forecasting methods. How accurate are your
predictions?"

The presenter made some comments about this being early days in the
development of the methods, but he said that already they had achieved
a rate of success which was 90% that of experiential forecasting. He
then went on to another questioner, but the WHE stuck his hand up
again. Finally it was the only hand still up, and the speaker
recognized him.

The WHE spoke: "Excuse me, sir, but this "experiential forecasting"
to which you referred - just what is experiential forecasting?"

The speaker replied "What is experiential forecasting? Experiential
forecasting is predicting that tomorrow's weather will be like today's."

Leigh