30 Oct 2009
In a speech to the British Association for the Advancement of Science in
1900, the most famous scientist of the day, Lord Kelvin, declared,
"Physics
is essentially complete".
"There is nothing new to be discovered in physics now," he said. "All that
remains is more and more precise measurement."
He did note a couple of "dark clouds on the horizon" but expected they
would
be erased without much trouble.
One cloud was the puzzle about the constancy of the speed of light; the
other how matter absorbed and emitted light. Just five years later Albert
Einstein's theories about both would shatter Lord Kelvin's world view.
Einstein wasn't as arrogant as Lord Kelvin. He was to say of his theories,
"No amount of experimentation can ever prove me right; a single experiment
can prove me wrong".
Karl Popper was enormously influenced by Einstein's theory of relativity
and
three others: Karl Marx's theory of history, Sigmund Freud's
psycho-analysis, and Alfred Adler's "individual psychology".
In the summer of 1919, Popper says he was "thrilled" by Arthur Eddington's
eclipse observations which were the first confirmation of Einstein's
theory
of gravitation. But it made him wonder about his other pet theories.
"I began to feel dubious about their claims to scientific status," he
said.
"My problem perhaps first took the simple form, 'What is wrong with
Marxism,
psycho-analysis, and individual psychology? Why are they so different from
physical theories, from Newton's theory, and especially from the theory of
relativity?"
He noted, "my friends who were admirers of Marx, Freud, and Adler, were
impressed by a number of points common to these theories, and especially
by
their apparent explanatory power.
These theories appear to be able to explain practically everything that
happened within the fields to which they referred. The study of any of
them
seemed to have the effect of an intellectual conversion or revelation,
open
your eyes to a new truth hidden from those not yet initiated. Once your
eyes
were thus opened you saw confirmed instances everywhere: the world was
full
of verifications of the theory. Whatever happened always confirmed it.
Thus
its truth appeared manifest; and unbelievers were clearly people who did
not
want to see the manifest truth; who refuse to see it, either because it
was
against their class interest, or because of their repressions which were
still "un-analysed" and crying aloud for treatment.
Popper became famous for his epistemological work demarking science from
pseudo-science. It boiled down to testability. If a theory could be
falsified by experimentation it was science, if it couldn't it wasn't.
So Popper would argue that to say any theory is "settled" means that you
are
not talking about science but pseudo-science.
By now it should be clear that I am building towards an act of heresy. In
mainstream political and scientific debate today what held true for
Einstein
does not hold true for climate science. Climate science we are endlessly
told is "settled".
But to make the, perfectly reasonable, point that science is never settled
risks being branded a "sceptic" or worse a "denier".
"Denier" is one of those words, like "racist", which is deliberately
designed to gag debate. And what is wrong with being a sceptic? The Greek
root of the word means "thoughtful" or "inquiring" and that used to be a
virtue.
If to question a science which relies so heavily on computer generated
modelling is to be a denier or a sceptic, then stack me up with the
heretics
and go find the matches. Because modelling is a black art and the models
will be wrong. They might understate or overstate the outcome but they
will
change over time. Model failure is so common there is a name for it: model
risk.
If you doubt how badly things can go with impressive models then consider
for a moment the recent financial crisis. A lot of very big companies paid
a
fortune to a cadre of mathematics and physics PhDs, called "quants", who
developed models that were supposed to eliminate risk. Turns out they got
it
hideously wrong and some believe they made a bad situation a whole lot
worse.
So, here is another piece of modern heresy, anyone who puts their faith in
computer predictions of the future, is dealing with digital astrology.
But the climate change debate is worse still. You can be branded a denier
if
you accept the problem and question the solutions.
This really began to concern me last year when I included Professor
Warwick
McKibbin in a television news story about emissions trading. He was
critical
of the Garnaut Report and I got a complaint from a PhD student in
economics.
She said McKibbin was a well known climate change denier and the ABC
should
not be running anything from people who did not believe in climate change.
Leaving aside the all-too-typical, and deeply disturbing, demand that
dissenters be silenced the other issue with the complaint was that
McKibbin
is internationally renowned for his work on climate change. He's also a
Reserve Bank board member and one of this country's pre-eminent
economists.
He just doesn't think much of the Government's climate change solutions
and
believes he has a much better plan. He's a smart guy; he might just be on
to
something.
So I come to praise sceptics not to bury them. Long may they prosper.
And here's a final thought from Popper about the dangers of being too
"credulous".
"A Marxist could not open a newspaper without finding on every page
confirming evidence for his interpretation of history; not only in the
news,
but also in its presentation - which revealed the class bias of the
paper -
and especially of course what the paper did not say. The Freudian analysts
emphasised that their theories were constantly verified by their "clinical
observations". As for Adler, I was much impressed by a personal
experience.
Once, in 1919, I reported to him a case which to me did not seem
particularly Adlerian, but which he found no difficulty in analysing in
terms of his theory of inferiority feelings, although he had not even seen
the child. Slightly shocked, I asked him how he could be so sure. "Because
of my thousandfold experience," he replied; whereupon I could not help
saying: "And with this new case, I suppose, your experience has become
thousand-and-one-fold."
http://blogs.abc.net.au/offair/2009/10/in-praise-of-the-sceptics.html
Warmest Regards
Bon z0
"It is a remarkable fact that despite the worldwide expenditure of perhaps
US$50 billion since 1990, and the efforts of tens of thousands of
scientists
worldwide, no human climate signal has yet been detected that is distinct
from natural variation."
Bob Carter, Research Professor of Geology, James Cook University,
Townsville
