My latest Wall Street Journal Mind and Matter column:
The list of scientific heretics who were persecuted for their
radical ideas but eventually proved right keeps getting longer.
Last month, Daniel Shechtman won the Nobel Prize for the discovery
of quasicrystals, having spent much of his career being told he was
wrong.
"I was thrown out of my research group. They said I brought shame
on them with what I was saying," he recalled, adding that the doyen
of chemistry, the late Linus Pauling, had denounced the theory with
the words: "There is no such thing as quasicrystals, only
quasi-scientists."
The Australian medical scientist Barry Marshall, who hypothesized
that a bacterial infection causes stomach ulcers, received similar
treatment and was taken seriously only when he deliberately
infected himself, then cured himself with antibiotics in 1984.
Eventually, he too won the Nobel Prize.
Drs. Shechtman and Marshall are on a distinguished list. Galileo,
Charles Darwin and Albert Einstein all had to run the gauntlet of
conventional wisdom in the scientific establishment. For a
profession whose very product is new knowledge, science seems
strangely resistant to novelty.
In the 1840s, Ignaz Semmelweiss's lonely battle to get the medical
establishment to accept that doctors were spreading childbed fever
from mother to mother cost him his job and his sanity (though his
prickly personality didn't help). Alec Gordon, a doctor in
Aberdeen, Scotland, had failed in the same quest five decades
before.
Next year will be the centenary of Alfred Wegener's theory of
continental drift. By the time he died in 1930, few scientists had
accepted the bizarre idea that continents could move like rafts. An
especially vehement attack by the eminent evolutionary biologist
George Gaylord Simpson in 1943 seemed to consign continental drift
to history's waste heap. Only in the 1960s, with the discovery of
plate tectonics, was Wegener rehabilitated.
I would hazard a guess that 90% of great scientists start out as
heretics. The problem is that 90% of scientific heretics are
talking nonsense.
For an instructive analogy, consider Meadow's Law, named after the
pediatrician Roy Meadow's theory that one sudden infant death in a
family is tragic, but two are suspicious and three means murder.
The logical flaw here is that though it's true that the probability
of more than one such death in a family is low, so is the
probability of multiple murders. Likewise, it's irrational to argue
from the high probability that a scientific genius was once a
heretic to the conclusion that a heretic is probably a scientific
genius.
After giving a lecture on scientific heresy last week, I was asked
how you can tell when a scientific heretic is right rather than
mad. I confessed that, as I've grown older, I've become more
confused on this point. The problem is not just that vindicated
heretics are rare, but also that the heretic who's right will be
just as partisan-avidly collecting evidence to confirm his idea-as
the heretic who's wrong.
Perhaps it's at least worth guessing which of today's heretics
will eventually win a Nobel Prize. How about the Dane Henrik
Svensmark? In 1997, he suggested that the sun's magnetic field
affects the earth's climate-by shielding the atmosphere against
cosmic rays, which would otherwise create or thicken clouds and
thereby cool the surface. So, he reasoned, a large part of the
natural fluctuations in the climate over recent millennia might
reflect variation in solar activity.
Dr. Svensmark is treated as a heretic mainly because his theory is
thought to hinder the effort to convince people that recent
climatic variation is largely manmade, not natural, so there is a
bias toward resisting his idea. That does not make it right, but
some promising recent experiments at CERN (the European
Organization for Nuclear Research) raise the probability that Dr.
Svensmark might yet prove to be a Shechtman.
