On Not Admitting You Are Wrong, or What Dembski and Wolfram Have in Common
Science often depends on experiments, and experiments are notoriously
prone to error. Even if the experiment's results are correct, the
conclusions may be wrong. And even if the experiment and conclusions
are correct, they may represent only part of the truth. Sometimes
scientists are simply wrong, and they need to admit it. While they
don't do experiments, a similar obligation falls on mathematicians.
Most mathematicians and scientists recognize this obligation. In 1989,
for example, the mathematician I. J. Good published a corrigendum to
one of his previous papers. This wouldn't be noteworthy except that
the paper he was correcting was published in 1941, nearly 50 years
before.
Unfortunately, it doesn't always work that way. A classic case is that
of Ren� Blondlot (1849-1930), a French physicist who believed he had
discovered a new kind of radiation, which he called "N-rays" in honor
of Nancy, his native city. You can read about this case in Walter
Gratzer's book The Undergrowth of Science, and I am following
Gratzer's account here.
N-rays, Blondlot said, had all sorts of unusual properties. They could
go through paper, wood, quartz, and mica, but not water or rock salt.
They were emitted by animal and plant tissue. When N-rays hit the
human eye, people could see better. Some other physicists confirmed
his results, and found other strange properties of the rays.
Blondlot's results were often based on very subjective data, such as a
line of glowing phosphor increasing or decreasing in brightness based
only on visual observations.
However, others failed to confirm his results, notably German
physicists such as Heinrich Rubens, Otto Lummer, and Paul Drude, and
English physicists such as Lord Rayleigh, Lord Kelvin, and William
Crookes. Nationality began to influence the controversy: one Blondlot
supporter later claimed the Germans could not detect the effect of the
rays because "their sensibilities were inferior and were further
blunted by their bruish diet of beer and sauerkraut" (Gratzer, p.20).
Ultimately, N-rays met their scientific death when R. W. Wood, a Johns
Hopkins physicist, visited Blondlot's laboratory. In a 1904 letter
published in Nature, he made a devastating revelation. While observing
an experiment in a dark room in which the N-rays were refracted by an
aluminum prism, Wood surreptitiously removed the prism from the
apparatus. The French experimenters, unaware of Wood's actions, went
on describing exactly the same phenomena as before.
But Blondlot and many of his supporters did not concede. One French
scientist, Turpain, attempted to reproduce Blondlot's results, failed,
and submitted his results to Comptes rendus for publication. They were
rejected by the editor who said, "Your results can be explained simply
by supposing that your eyes are insufficiently sensitive to appreciate
the phenomena." (Gratzer, p. 21) Turpain replied, "If N-rays can only
be observed by rare privileged individuals then they no longer belong
to the domain of experiment." (ibid) When Blondlot died in 1930, his
posthumous papers showed he continued to believe in and experiment on
N-rays for many years after Wood's debunking.
The case of N-rays is a spectacular example of a failure of a
scientist to admit he was wrong. Even in this case, though, science's
self-correction won the day. After Wood's debunking, N-rays vanished
from the scientific literature.
Blondlot's tale is a cautionary one. By contrast, I offer a case where
the proper behavior was displayed, from Richard Dawkins' 1996 Richard
Dimbleby lecture:
A formative influence on my undergraduate self was the response of a
respected elder statesmen of the Oxford Zoology Department when an
American visitor had just publicly disproved his favourite theory. The
old man strode to the front of the lecture hall, shook the American
warmly by the hand and declared in ringing, emotional tones: "My dear
fellow, I wish to thank you. I have been wrong these fifteen years."
And we clapped our hands red.
Admitting you are wrong is a basic part of the mathematical and
scientific ethic. In the days of the Internet, mea culpas can be more
public and more effectively distributed then ever before. For both of
my published books, for example, I maintain public errrata pages. The
errata and addenda for my 1996 book now take up ten pages!
But not everyone agrees. Take two controversial books published in the
last few years: A New Kind of Science by Stephen Wolfram, and No Free
Lunch, by William Dembski.
Wolfram's book was published in 2002. Roughly speaking, the main
thesis is that even very simple interactions give rise to complex
phenomena that are hard to predict. Over 1280 pages, this thesis is
developed and applied to many different areas, including mathematics,
physics, economics, and biology; it is touted as a genuine revolution
in science. Critics, generally, speaking have not been kind. (See here
for a compendium of many different reviews.) I find the book
interesting, with many fascinating digressions. The pictures are nice.
But the importance of the main thesis is wildly overstated, and
Wolfram never really gives a formal definition of "complex" that would
satisfy a mathematician or physicist; rather, he relies on an informal
definition of complexity based on appearance to the human visual
system. If he did use a more formal definition -- let's say Kolmogorov
complexity -- then his claims become incoherent, trivial, or wrong.
Dembski's book was also published in 2002. Dembski defines a new kind
of complexity, which he calls "specified complexity" or "complex
specified information". He then discusses properties of this measure,
which he claims satisfies a law called "The Law of Conservation of
Information", and concludes that specified complexity cannot be
generated by natural causes. He then finds specified complexity in
biological structures such as the [sic] bacterial flagellum, and
concludes the flagellum cannot have arisen through natural causes.
Needless to say, most reviewers have not been kind to Dembski either.
(See here for some reviews.) Like Wolfram, Dembki's definition of
complexity suffers from subjectivity, as it depends critically on the
knowledge base of the observer. When one tries to make the definition
more precise, Dembski's claims become incoherent, trivial, or wrong.
The analogy between the work of Wolfram and Dembski is imperfect.
Wolfram, for example, has a genuine record of achievement, winning a
MacArthur "genius" grant, and creating the software system
Mathematica. Many of his papers continue to be cited by scientists and
mathematicians. By contrast, Dembski, though possessing numerous
degrees, has had a negligible impact on mathematics and science.
Nevertheless, there is one thing they have in common, and this brings
me back to the start of this entry. Neither Wolfram nor Dembski have
seen fit to make available errata pages for their books. In this, they
fail in their intellectual obligation. Back in October 2002, I sent
Wolfram a list of various errata in his book. Eventually one of his
assistants acknowledged the errors, but Wolfram has never made them
public. (Some of them can be seen here, due to the persistence of
Evangelos Georgiadis.) Considering the extensive web presence for A
New Kind of Science, surely an errata page is not asking too much.
Similarly, in April 2002 I sent Dembski a review in which I pointed
out many mistakes in No Free Lunch, but Dembski only acknowledged one
of these errors publicly and it took him three years. (My review later
appeared in the journal BioSystems.)
Both Wolfram and Dembski seem to be taking a page from Canadian
feminist Nellie McClung, who reportedly said, "Never retract, never
explain, never apologize -- get the thing done and let them howl!"
This might be a good motto for a social activist, but for a scientist
or mathematician it is a dereliction of duty. If you want to be taken
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