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The Big Crunch
by David Goodstein
NCAR 48 Symposium, Portland, OR September 19, 1994
According to modern cosmology, the Universe began about 10 or 15 billion years ago
in an event known as the Big Bang. It has been expanding ever since. What
we do not know is whether it will go on expanding forever. If the density
of matter in the Universe is sufficiently large, gravitational forces will
eventually cause the Universe to stop expanding, and then to start falling
back in upon itself. If that happens, the Universe will end in a second
cataclysmic event that cosmologists call The Big Crunch.
I would like to present to you this morning a rather analogous theory of
the history of science. According to this theory, modern science appeared
on the scene, in Europe, almost 300 years ago, and in this country a little
more than a century ago. In each case it proceeded to expand at a frightening
exponential rate. Exponential expansion cannot go on forever, and so the
expansion of science, unlike the expansion of the Universe, was guaranteed
to come to an end. I will argue that, in science, the Big Crunch occurred
about 25 years ago, and we have been trying to ignore it ever since. What
we have to do now is to solve a problem that has never even occurred to the
cosmologists. The problem is, what do you do after The Big Crunch?
The situation is illustrated by this graph. The upper curve was first
published in 1961, in a book called Science Since Babylon by Derek da Solla
Price. It is a plot, on a semi-logarithmic scale, of the cumulative number
of scientific journals founded world-wide on the vertical scale, versus time
in years on the horizontal. A straight line on this kind of graph means
pure exponential growth. In exponential growth, the bigger a thing is, the
faster it grows. According to Price, this graph is a suitable stand-in for
any quantitative measure of the size of science. As you can see, it shows
that science seemed to spring into being around 1700 (the Big Bang might
have been the publication of Newton's Principia in 1687), and it expanded
exponentially, growing about a factor of 10 every 50 years, up until the
time Price made this graph.
Price wisely predicted that this behavior could not go on forever. He
was right, of course. The straight line in the plot extrapolates to one
million journals by the year 2000. Instead, the number of scientific journals
in the world today, as we approach the millenium, is a mere 40,000. This
sorry failure of the publishing industry to keep up with our expectations
often leaves us scientists with nothing to read by the time we reach the
end of the week.
The point is that the era of exponential growth in science is already over.
The number of journals is one measure, but all others tend to agree. In
particular, it applies to the number of scientists around. It may still
be true that 90% of all the scientists who have ever lived are alive today,
and that statement has been true at any given time for nearly 300 years.
But it cannot go on being true for very much longer. Even with the huge
increase in world population in this century, only about one-twentieth of
all the people who have ever lived are alive today. It is a simple mathematical
fact that if scientists keep multiplying faster than people, there will soon
be more scientists than there are people. That seems very unlikely to happen.
To emphasize that point, I have plotted, on the same scale as Price's growth
curve, the number of Ph.Ds in physics produced each year in the United States.
Like any other quantitative measure of science, its behavior is much like
Price's curve. The graph shows that science started later in the U.S. than
in Europe. The first Ph.D was awarded soon after the Civil War, around
1870. By the turn of the century the number was about 10 per year, by 1930
about 100 per year, and by 1970, 1000 per year. The curve extrapolates to
about 10,000 a year today, and one million a year in 2050. But that's not
what happened. The growth stopped cold around 1970, and the number has oscillated
around 1000 per year ever since. We didn't notice it at the time, but, at
least in physics, The Big Crunch happened around 1970.
Although hardly anyone noticed the change at the time, it is difficult
to imagine a more dramatic contrast than the decades just before 1970, and
the decades since then. Those were the years in which science underwent
an irreversible transformation into an entirely new regime. Let's look back
at what has happened in those years in light of this historic transition.
The period 1950-1970 was a true golden age for American science. Young
Ph.D's could choose among excellent jobs, and anyone with a decent scientific
idea could be sure of getting funds to pursue it. The impressive successes
of scientific projects during the Second World War had paved the way for
the federal government to assume responsibility for the support of basic
research. Moreover, much of the rest of the world was still crippled by
the after-effects of the war. At the same time, the G.I. Bill of Rights
sent a whole generation back to college transforming the United States from
a nation of elite higher education to a nation of mass higher education.
Before the war, about 8% of Americans went to college, a figure comparable
to that in France or England. By now more than half of all Americans receive
some sort of post-secondary education. The American academic enterprise grew
explosively, especially in science and technology. The expanding academic
world in 1950-1970 created posts for the exploding number of new science
Ph.D.s, whose research led to the founding of journals, to the acquisition
of prizes and awards, and to increases in every other measure of the size
and quality of science. At the same time, great American corporations such
as AT&T, IBM and others decided they needed to create or expand their
central research laboratories to solve technological problems, and also to
pursue basic research that would provide ideas for future developments. And
the federal government itself established a network of excellent national
laboratories that also became the source of jobs and opportunities for aspiring
scientists. Even so, that explosive growth was merely a seamless continuation
of a hundred years of exponential growth of American science. It seemed to
one and all (with the notable exception of Derek da Solla Price) that these
happy conditions would go on forever.
By now, in the 1990's, the situation has changed dramatically. With the
Cold War over, National Security is rapidly losing its appeal as a means
of generating support for scientific research. There are those who argue
that research is essential for our economic future, but the managers of the
economy know better. The great corporations have decided that central research
laboratories were not such a good idea after all. Many of the national laboratories
have lost their missions and have not found new ones. The economy has gradually
transformed from manufacturing to service, and service industries like banking
and insurance don't support much scientific research. To make matters worse,
the country is almost 5 trillion dollars in debt, and scientific research
is among the few items of discretionary spending left in the national budget.
There is much wringing of hands about impending shortages of trained scientific
talent to ensure the Nation's future competitiveness, especially since by
now other countries have been restored to economic and scientific vigor,
but in fact, jobs are scarce for recent graduates. Finally, it should be
clear by now that with more than half the kids in America already going to
college, academic expansion is finished forever.
Actually, during the period since 1970, the expansion of American science
has not stopped altogether. Federal funding of scientific research, in inflation-corrected
dollars, doubled during that period, and by no coincidence at all, the number
of academic researchers has also doubled. Such a controlled rate of growth
(controlled only by the available funding, to be sure) is not, however, consistent
with the lifestyle that academic researchers have evolved. The average American
professor in a research university turns out about 15 Ph.D students in the
course of a career. In a stable, steady-state world of science, only one
of those 15 can go on to become another professor in a research university.
In a steady-state world, it is mathematically obvious that the professor's
only reproductive role is to produce one professor for the next generation.
But the American Ph.D is basically training to become a research professor.
It didn't take long for American students to catch on to what was happening.
The number of the best American students who decided to go to graduate school
started to decline around 1970, and it has been declining ever since.
In the meantime, a surprising phenomenon has taken place. The golden age
of American academic science produced genuine excellence in American universities.
Without any doubt at all, we lead the world in scientific training and research.
It became necessary for serious young scientists from everywhere else either
to obtain an American Ph.D, or at least to spend a year or more of postgraduate
or postdoctoral study here. America has come to play the role for the rest
of the world, especially the emerging nations of the Pacific rim, that Europe
once played for young American scientists, and it is said, that Greece once
played for Rome. We have become the primary source of scientific culture
and learning for everyone. Almost unnoticed, over the past 20 years the
missing American graduate students have been replaced by foreign students.
In addition, these years have seen the burgeoning of postdoctoral research
positions, a kind of holding tank for scientific talent that allows young
researchers to delay confronting reality for 3 or 6 years or more. These
are the changes that have permitted the American research universities to
pretend that nothing changed when The Big Crunch came, 25 years ago.
Since we began with a cosmological analogy, let us return to one now.
An unfortunate space traveler, falling into a black hole, is utterly and
irretrievably doomed, but that is only obvious to the space traveler. In
the perception of an observer hovering above the event horizon, the space
traveler's time slows down, so that it seems as if catastrophe can forever
be put off into the future. Something like that has happened in our research
universities. The good times ended forever around 1970, but by importing
students, and employing Ph.D's as temporary postdocs, we have stretched time
out, pretending that nothing has changed, waiting for the good times to return.
We have about as much chance as the space traveler.
In the meantime, the real crisis that is coming has started to produce
a number of symptoms, some alarming and some merely curious. One of these
is what I like to call The Paradox of Scientific Elites and Scientific Illiterates.
The paradox is this: as a lingering result of the golden age, we still
have the finest scientists in the world in the United States. But we also
have the worst science education in the industrialized world. There seems
to be little doubt that both of these seemingly contradictory observations
are true. American scientists, trained in American graduate schools produce
more Nobel Prizes, more scientific citations, more of just about anything
you care to measure than any other country in the world; maybe more than
the rest of the world combined. Yet, students in American schools consistently
rank at the bottom of all those from advanced nations in tests of scientific
knowledge, and furthermore, roughly 95% of the American public is consistently
found to be scientifically illiterate by any rational standard. How can
we possibly have arrived at such a result? How can our miserable system
of education have produced such a brilliant community of scientists? That
is what I mean by The Paradox of the Scientific Elites and the Scientific
Illiterates.
The question of how we educate our young in science lies close to the heart
of the issues we have been discussing. The observation that, for hundreds
of years the number of scientists had been growing exponentially means, quite
simply, that the rate at which we produced scientists has always been proportional
to the number of scientists that already existed. We have already seen how
that process works at the final stage of education, where each professor
in a research university turns out 15 Ph.D's, most of those wanting to become
research professors and turn out 15 more Ph.D's.
Recently, however, a vastly different picture of science education has
been put forth and has come to be widely accepted. It is the metaphor of
the pipeline. The idea is that our young people start out as a torrent of
eager, curious minds anxious to learn about the world, but as they pass through
the various grades of schooling, that eagerness and curiosity is somehow
squandered, fewer and fewer of them showing any interest in science, until
at the end of the line, nothing is left but a mere trickle of Ph.D's. Thus,
our entire system of education is seen to be a leaky pipeline, badly in need
of repairs. The leakage problem is seen as particularly severe with regard
to women and minorities, but the pipeline metaphor applies to all. I think
the pipeline metaphor came first out of the National Science Foundation,
which keeps careful track of science workforce statistics (at least that's
where I first heard it). As the NSF points out with particular urgency,
women and minorities will make up the majority of our working people in future
years. If we don't figure out a way to keep them in the pipeline, where
will our future scientists come from?
I believe it is a serious mistake to think of our system of education as
a pipeline leading to Ph.D's in science or in anything else. For one thing,
if it were a leaky pipeline, and it could be repaired, then as we've already
seen, we would soon have a flood of Ph.D's that we wouldn't know what to
do with. For another thing, producing Ph.Ds is simply not the purpose of
our system of education. Its purpose instead is to produce citizens capable
of operating a Jeffersonian democracy, and also if possible, of contributing
to their own and to the collective economic well being. To regard anyone
who has achieved those purposes as having leaked out of the pipeline is silly.
Finally, the picture doesn't work in the sense of a scientific model: it
doesn't make the right predictions. We have already seen that, in the absence
of external constraints, the size of science grows exponentially. A pipeline,
leaky or otherwise, would not have that result. It would only produce scientists
in proportion to the flow of entering students.
I would like to propose a different and more illuminating metaphor for
American science education. It is more like a mining and sorting operation,
designed to cast aside most of the mass of common human debris, but at the
same time to discover and rescue diamonds in the rough, that are capable
of being cleaned and cut and polished into glittering gems, just like us,
the existing scientists. It takes only a little reflection to see how much
more this model accounts for than the pipeline does. It accounts for exponential
growth, since it takes scientists to identify prospective scientists. It
accounts for the very real problem that women and minorities are woefully
underrepresented among the scientists, because it is hard for us, white,
male scientists to perceive that once they are cleaned and cut and polished,
they will look like us. It accounts for the fact that science education is
for the most part a dreary business, a burden to student and teacher alike
at all levels of American education, until the magic moment when a teacher
recognizes a potential peer, at which point it becomes exhilarating and successful.
Above all, it resolves the paradox of Scientific Elites and Scientific Illiterates.
It explains why we have the best scientists and the most poorly educated
students in the world. It is because our entire system of education is designed
to produce precisely that result.
American education is much-maligned, and of course it suffers from severe
problems that I need not go into here. Nevertheless, it was remarkably well
suited to the exponential expansion era of science. Mass higher education,
essentially an American invention, means that we educate nearly everyone,
rather poorly. The alternative system, gradually going out of style in Europe
these days, is to educate a select few rather well. But we too have rescued
elitism from the jaws of democracy, in our superior graduate schools. Our
students finally catch up with their European counterparts in about the second
year of graduate school (this is true, at least, in physics) after which
they are second to none. When, after about 1970, the gleaming gems produced
by this assembly line at the end of the mining and sorting operation were
no longer to be found at home, the humming machinery kept right on going,
fed by ore imported from across the oceans.
To most of us who are professors, finding gems to polish is not our principal
problem. Recently, Leon Lederman, one of the leaders of American science
published a pamphlet called Science -- The End of the Frontier. The title
is a play on Science -- The Endless Frontier, the title of the 1940's report
by Vannevar Bush that led to the creation of the National Science Foundation
and helped launch the Golden Age described above. Lederman's point is that
American science is being stifled by the failure of the government to put
enough money into it. I confess to being the anonymous Caltech professor
quoted in one of Lederman's sidebars to the effect that my main responsibility
is no longer to do science, but rather it is to feed my graduate students'
children. Lederman's appeal was not well received in Congress, where it
was pointed out that financial support for science is not an entitlement
program, nor in the press, where the Washington Post had fun speculating
about hungry children haunting the halls of Caltech. Nevertheless, the problem
Lederman wrote about is very real and very painful to those of us who find
that our time, attention and energy are now consumed by raising funds rather
than teaching and doing research. However, although Lederman would certainly
disagree with me, I firmly believe that this problem cannot be solved by
more government money. If federal support for basic research were to be
doubled (as many are calling for), the result would merely be to tack on
a few more years of exponential expansion before we'd find ourselves in exactly
the same situation again. Lederman has performed a valuable service in promoting
public debate of an issue that has worried me for a long time (the remark
he quoted is one I made in 1979), but the issue itself is really just a
symptom of the larger fact that the era of exponential expansion has come
to an end. The End of the Frontier could just as well have been called The
Big Crunch.
The crises that face science are not limited to jobs and research funds.
Those are bad enough, but they are just the beginning. Under stress from
those problems, other parts of the scientific enterprise have started showing
signs of distress. One of the most essential is the matter of honesty and
ethical behavior among scientists.
The public and the scientific community have both been shocked in recent
years by an increasing number of cases of fraud committed by scientists.
There is little doubt that the perpetrators in these cases felt themselves
under intense pressure to compete for scarce resources, even by cheating
if necessary. As the pressure increases, this kind of dishonesty is almost
sure to become more common.
Other kinds of dishonesty will also become more common. For example, peer
review, one of the crucial pillars of the whole edifice, is in critical danger.
Peer review is used by scientific journals to decide what papers to publish,
and by granting agencies such as the National Science Foundation to decide
what research to support. Journals in most cases, and agencies in some cases
operate by sending manuscripts or research proposals to referees who are
recognized experts on the scientific issues in question, and whose identity
will not be revealed to the authors of the papers or proposals. Obviously,
good decisions on what research should be supported and what results should
be published are crucial to the proper functioning of science.
Peer review is usually quite a good way to identify valid science. Of
course, a referee will occasionally fail to appreciate a truly visionary
or revolutionary idea, but by and large, peer review works pretty well so
long as scientific validity is the only issue at stake. However, it is not
at all suited to arbitrate an intense competition for research funds or for
editorial space in prestigious journals. There are many reasons for this,
not the least being the fact that the referees have an obvious conflict of
interest, since they are themselves competitors for the same resources.
This point seems to be another one of those relativistic anomalies, obvious
to any outside observer, but invisible to those of us who are falling into
the black hole. It would take impossibly high ethical standards for referees
to avoid taking advantage of their privileged anonymity to advance their
own interests, but as time goes on, more and more referees have their ethical
standards eroded as a consequence of having themselves been victimized by
unfair reviews when they were authors. Peer review is thus one among many
examples of practices that were well suited to the time of exponential expansion,
but will become increasingly dysfunctional in the difficult future we face.
We must find a radically different social structure to organize research
and education in science after The Big Crunch. That is not meant to be an
exhortation. It is meant simply to be a statement of a fact known to be
true with mathematical certainty, if science is to survive at all. The new
structure will come about by evolution rather than design, because, for one
thing, neither I nor anyone else has the faintest idea of what it will turn
out to be, and for another, even if we did know where we are going to end
up, we scientists have never been very good at guiding our own destiny.
Only this much is sure: the era of exponential expansion will be replaced
by an era of constraint. Because it will be unplanned, the transition is
likely to be messy and painful for the participants. In fact, as we have
seen, it already is. Ignoring the pain for the moment, however, I would
like to look ahead and speculate on some conditions that must be met if science
is to have a future as well as a past.
It seems to me that there are two essential and clearly linked conditions
to consider. One is that there must be a broad political consensus that
pure research in basic science is a common good that must be supported from
the public purse. The second is that the mining and sorting operation I've
described must be discarded and replaced by genuine education in science,
not just for the scientific elite, but for all the citizens who must form
that broad political consensus.
Basic research is a common good for two reasons: it helps to satisfy the
human need to understand the universe we inhabit, and it makes new technologies
possible. It must be supported from the public purse because it does not
yield profits if it is supported privately. Because basic research in science
flourishes only when it is fully open to the normal processes of scientific
debate and challenge, the results must be available to all. That is why
it is always more profitable to use someone else's basic research than to
support your own. For most people it will also always be easier to let someone
else do the research. In other words, not everyone wants to be a scientist.
It follows that in order to serve the need of satisfying human curiosity
we scientists must find a way to teach science to non-scientists.
That job may turn out to be impossible. The frontiers of science have moved
far from the experience of ordinary persons. Unfortunately, we have never
developed a way to bring people along as informed tourists of the vast terrain
we have conquered, without training them to become professional explorers.
If it turns out to be impossible to do that, the people may decide that
the technological trinkets we send back from the frontier are not enough
to justify supporting the cost of the expedition. If that happens, science
will not merely stop expanding, it will die.
Let me finish by summarizing what I've been trying to tell you. We stand
at an historic juncture in the history of science. The long era of exponential
expansion ended decades ago, but we have not yet reconciled ourselves to
that fact. The present social structure of science, by which I mean institutions,
education, funding, publications and so on all evolved during the period
of exponential expansion, before The Big Crunch. They are not suited to the
unknown future we face. Today's scientific leaders, in the universities,
government, industry and the scientific societies are mostly people who came
of age during the golden era, 1950 - 1970. I am myself part of that generation.
We think those were normal times and expect them to return. But we are wrong.
Nothing like it will ever happen again. It is by no means certain that science
will even survive, much less flourish, in the difficult times we face. Before
it can survive, those of us who have gained so much from the era of scientific
elites and scientific illiterates must learn to face reality, and admit that
those days are gone forever.
I think we have our work cut out for us.
Previous versions of this article have been published as "Scientific Ph.D Problems", American Scholar, vol. 62, no. 2, spring 1993, and "Scientific Elites and Scientific Illiterates", Ethics, Values and the Promise of Science, Forum Proceedings, Sigma Xi, The Science Research Society, February 25-26, 1993, pg. 61, and Engineering and Science Spring 1993, vol. 56, no. 3, pg. 22.
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