麻豆传媒

SCIENCE has a glorious and heroic history. In their ingenious experiment in
1887, for example, American physicists Albert Michelson and Edward Morley showed
that light travelled at the same speed both along and across the path of the
Earth in its orbit round the Sun. In a single experiment, they found proof
positive that the velocity of light is a constant, and set the stage for
Einstein to formulate his special theory of relativity. In 1919, Arthur
Eddington pushed physics forward with a similarly telling experiment, conducted
during a total eclipse. Light, he found, was bent as it passed through the
gravitational field of the Sun by just the right amount to fit with Einstein鈥檚
general theory of relativity and twice as much as it should have been under
Newton鈥檚 theory. This triumphant verification of general relativity made front
page headlines in The Times.

So far, so good鈥攐r not. This is physics history, as written in
textbooks by scientists themselves. In this account, the definitive results of
well-conceived experiments decide between one theory and another. But the
history of science is too important to be left to scientists鈥攖hey distort
it shamelessly.

In our book The Golem, published in 1993, Trevor Pinch of Cornell
University and I revealed that these accounts of the two famous experiments are
wrong. The Michelson-Morley experiment never satisfied Michelson, and physicists
were still arguing over the behaviour of light into the 1930s, with experiments
designed to plug holes in the original. As for Eddington鈥檚 observations, they
were hopelessly ambiguous, and it took many decades for scientists to agree on
how much light really bends in a gravitational field.

The distortions that typify textbook history wouldn鈥檛 be so worrying if
scientists were its only consumers. But history of science is what tells all of
us about the nature of knowledge. From it we learn how reliable knowledge should
be made, and how secure that knowledge is. Worse yet, the distortions are
infectious.

Over the past few years, we have been studying how the myths of 鈥減ure鈥�
science affect our understanding of areas of science outside physics, as well as
of technology, economics and medicine. In each case, we have found that what
people expect from applied science is distorted by the sterilised picture they
have of pure science. When people see a new technology in trouble, or a medical
innovation gone awry, they tend to think it must be the result of human
incompetence, when it is often just the counterpart of hard-to-resolve disputes
in science itself.

The Golem, especially the chapter on the foundations of relativity,
touched a nerve in the scientific community. Some critics distorted what we
said, and displayed more anger than intellectual curiosity. But others made
sensible criticisms. Among these was the claim that scientists did not believe
that the two famous experiments were particularly important in the history of
relativity, that we had invented for the standard story a 鈥済host audience鈥� so as
to dramatise our 鈥渞evelations鈥�.

Telling it like it is

Surprised by this, we surveyed some textbooks to see what scientists were
telling their students about the history of relativity. We found that there were
one or two scientists who had described the experiments with care. As late as
1967, the distinguished cosmologist Hermann Bondi wrote that Michelson-Morley
and similar experiments 鈥渁re even nowadays difficult experiments in which no
great accuracy can be obtained鈥�.

But 16 of the remaining 25 accounts misrepresent the experiment as being more
complete than it was, misrepresent its importance in the history of relativity,
or misrepresent the later experiments that did find that the velocity of light
depended on its direction of travel. Moreover, nearly all the texts discuss the
Michelson-Morley experiment in isolation, lending it misplaced significance by
default.

For the Eddington eclipse observations, we again found an excellent account
written by a scientist. In 1972, physicist Dennis Sciama, now of the
International School for Advanced Studies in Trieste, Italy, wrote that
鈥淓instein鈥檚 prediction had not been verified as decisively as was once believed
. . . there are several cases in astronomy where knowing the `right鈥� answer has
led to observed results later shown to be beyond the power of the apparatus to
detect鈥�. This is accurate history.

Of the remaining 15 textbook accounts, however, 12 say that the experiment
was more accurate than it was, with 3 making incorrect claims about succeeding
experiments. Perhaps most surprising, the historical accuracy of an account
seems unrelated to either the date of publication or the eminence of the
scientist-author. Neither Bondi鈥檚 nor Sciama鈥檚 reservations have had much effect
on subsequent authors, who continue to build the myth of the accuracy and
decisiveness of the two experiments.

We don鈥檛 believe that physicists are setting out to lie about the history of
their subject. More likely, they concentrate on physics when they write rather
than history. None of these textbooks is wrong as far as the modern view of
physics is concerned. In this respect, the experiments might as well have been
done as accurately and decisively as the textbooks say.

As far as physics is concerned, who cares that in the 1920s, D. C. Miller
鈥渄iscovered鈥� the non-constancy of the velocity of light, and won a prize for it
from the American Association for the Advancement of Science. Who cares that, in
1933, he published a paper in Reviews of Modern Physics concluding that
the best experimental evidence to date showed that the Michelson and Morley
result was wrong. This was all a mistake. And we now know that Eddington was
right, too.

So perhaps the textbooks are not really presenting history, but physics
dressed up in historical guise so as to make it easier to remember. That would
be fine if the history of physics were only for physicists or if everyone could
tell the difference between history as history and the 鈥渇at-free history鈥� of the
texts and popularisations.

Unfortunately, these differences are not obvious and the resulting myths
pervade the whole of our society. Myths of this sort provide our basic beliefs
about what excellent knowledge is supposed to be like. Knowledge that does not
live up to the heroic standard is found wanting.

This is damaging to science itself, as it sets up the conditions for its own
failure. But the damaging repurcussions of these myths extend far beyond natural
science: they damage the political system by warping all our expectations of
what science can deliver. And they skew our vision of technology. Uncertainties
and failures in technology can be best understood in the light of what is
perfectly normal in the very best of science. As with relativity, when
technologies are tested, it often takes a very long time for the meaning of
tests to become clear.

Claims shot down

How successful, for example, were Patriot missiles in shooting down Iraqi
Scuds during the Gulf War? Claims about the Patriot鈥檚 success range from nearly
100 per cent to zero. Astonishingly, seven years after the war, the argument
still continues, with the lower end of the scale slowly winning out. How is it
possible to be so uncertain about whether your defence missiles were stopping
incoming missiles?

Here are some of the problems. If there are explosions on the ground, it may
be hard to tell whether they were caused by Scuds, or by Patriots that had dived
into the ground while chasing bits of debris, or by the exploding fuel tanks of
destroyed Scuds. So it is not so easy to know how many Scuds went unscathed. If
there are no explosions, on the other hand, it might be because the Patriots
were successful, or because the Scuds were duds.

Again, if a Patriot was seen diving into the ground and exploding, that means
that one of the known explosions wasn鈥檛 from a Scud and one less Scud explosion
must imply that Patriots had shot down one more Scud than ground damage would
suggest. Failure becomes success.

On top of all this, the various parties, such as the military and
manufacturers, are playing subtle games with the meaning of 鈥渟uccess鈥�. If
Patriots destroyed no Scuds at all but kept Israel out of the war, maintaining
the fragile Western alliance, is that a 鈥渟uccess鈥� for Patriot? Once one
understands the conflicting aims of the political, military and commercial
parties involved, it becomes clear why it is hard to be certain about more
subtle effects such as 鈥淕ulf War Syndrome鈥�. Technological questions, like
scientific ones, cannot always be answered by simple appeals to observation or
experiment.

The myths about science spread confusion in other areas too. Consider the
鈥淪even Wise Men鈥濃�攖he now disbanded group of economists who advised the
British government over the past decade. Econometric modelling is notoriously
poor for predicting the economy, but it鈥檚 really not much worse than weather
forecasting. Econometricians are wise about the workings of the economy, an area
where wisdom may be the best we can hope for. Even so, in an area like
economics, myths can lead to scientism, the over-zealous desire to make things
seem 鈥渟cientific鈥�.

One can see this kind of envious attitude in a remark made by one of the
econometricians themselves, who, regretting the lack of certainty in his own
forecasts, said: 鈥淸In econometrics] You don鈥檛 get the one definitive experiment
which shows you that, you know, the speed of light is the same in all
directions.鈥� Thus do the myths pervade society.

Stripping them away can be beneficial. In the interaction between AIDS
patients and the medical profession over the testing of new drugs, it became
clear all too slowly to the doctors on the American West Coast that their
subjects had real expertise in the case of drugs testing and real power to
change the course of such tests鈥攐r even to ruin them.

The AIDS patients knew what they counted as reasonable risks in choosing
between promising but untested treatments and the inevitable progress of the
disease in those taking placebos in clinical trials. They preferred test regimes
which compared AIDS groups taking different treatments to full-scale
placebo-controlled trials. Because of the solidarity of the gay community of San
Francisco, the AIDS patients had the power to stop such trials by pooling the
medicines of the control and experimental groups.

On the other hand, it slowly became clear to the AIDS patients that the
doctors had good reasons for some of their procedures, and that to maximise
their own input, they needed to learn some medical science. Though taking
placebos seemed tantamount to condemning the control group to death, there were
circumstances when it was the quickest way to find out if a drug worked. A
relationship that began in mutual distrust slowly developed into a partnership
between those with and without medical degrees. And the most life saving way of
testing the new drugs was established.

Consider also the interaction between British government scientists and sheep
farmers in Cumbria, England, after their fields were contaminated following the
Chernobyl explosion in 1986. This began in mutual distrust but a degree of
partnership emerged as the farmers鈥� understanding of sheep ecology came to be
appreciated by the scientists.

The odd thing is that among the confused consumers of scientific myths are
scientists themselves, who base their expectations of themselves on a past
populated with heroes capable of creating decisive proofs and certainties that
approach the status of mystical revelation. Pity the new PhD student carrying
such a burden.

Scientists often complain that journalists seek black and white answers when
all science can offer is shades of grey. In a submission to the House of Commons
Science and Technology Committee鈥檚 inquiry on scientific advice, the Royal
Society complained that 鈥済overnment departments can be too defensive when
dealing with often inconclusive results of cutting-edge science. They block
public access to information and do not share problems鈥� Whitehall puts a
premium on an answer for every situation, irrespective of scientific
robustness.鈥� This example could be replicated anywhere in the world.

But these complaints will have a hollow ring while science remains two-faced.
The Royal Society may regret what the government makes of science, and yet in
its approach to public understanding of science, its less reflective
spokespersons assume the effortless superiority of a knowledge aristocracy, and
trade in mythological history.

Some of the less temperate reactions to The Golem reveal how deeply
embedded that attitude is among an important and vocal groups of scientists. We
thought we were doing something uncontentious鈥攑ointing out, on the basis
of careful observations, that the history of certain passages of science was not
as told. We thought we were systematically explaining what much science
journalism now takes for granted鈥攖hat even the best passages of science
have often been disputed and that these disputes go on for decades. What we
encountered, along with responsible critiques, was scientific
fundamentalism鈥攖he determination to preserve an image of science as a
quasi-religion, or 鈥渉igher superstition 鈥�.

There is nothing to lose but hubris, and there is everything to gain,
including increased respect, from science restructuring its image as a body of
expertise rather than a complete way of being in the world. Science should not
compete with superstitions and religions but present itself as outside such
debates. Science would still be respected as the pre-eminent route to sound
knowledge.

The value of careful, repeated observations and systematic analysis compared
with guesswork, prejudice, inspiration or revelation, ought to be self-evident.
Among those for whom it is not self-evident, quasi-religious arguments will only
invite a more determined reaction.