"WHAT HAVE YOU CHANGED YOUR MIND ABOUT?"
Panasonic Professor of Robotics,
MIT, and CTO, iRobot Corp; author Flesh
as the Ultimate Metaphor
science, including mine, treats living systems as mechanisms
at multiple levels of abstraction. As we talk about how
one bio-molecule docks with another our explanations are purely
mechanistic and our science never invokes "and then the
soul intercedes and gets them to link up". The underlying
assumption of molecular biologists is that their level of mechanistic
explanation is ultimately adequate for high level mechanistic
descriptions such as physiology and neuroscience to build on
as a foundation.
of us who are computer scientists by training, and I'm afraid
many collaterally damaged scientists of other stripes, tend
to use computation as the mechanistic level of explanation
for how living systems behave and "think". I
originally gleefully embraced the computational metaphor
we look back over recent centuries we will see the brain described
as a hydrodynamic machine, clockwork, and as a steam engine. When
I was a child in the 1950's I read that the human brain was
a telephone switching network. Later it became a digital
computer, and then a massively parallel digital computer. A
few years ago someone put up their hand after a talk I had
given at the University of Utah and asked a question I had
been waiting for for a couple of years: "Isn't the human
brain just like the world wide web?". The brain
always seems to be one of the most advanced technologies that
we humans currently have.
metaphors we have used in the past for the brain have not stood
the test of time. I doubt that our current metaphor of
the brain as a network of computers doing computations is going
to stand for all eternity either.
that I do not doubt that there are mechanistic explanations
for how we think, and I certainly proceed with my work of trying
to build intelligent robots using computation as a primary
tool for expressing mechanisms within those robots.
I have relatively recently come to question computation as
the ultimate metaphor to be used in both the understanding
of living systems and as the only important design tool for
engineering intelligent artifacts.
of my colleagues have managed to recast Pluto's orbital behavior
as the body itself carrying out computations on forces that
apply to it. I think we are perhaps better off using
Newtonian mechanics (with a little Einstein thrown in) to understand
and predict the orbits of planets and others. It is so
we can think about spike trains as codes and worry about neural
coding. We can think about human memory as data storage
and retrieval. And we can think about walking over rough
terrain as computing the optimal place to put down each of
our feet. But I suspect that somewhere down the line
we are going to come up with better, less computational metaphors. The
entities we use for metaphors may be more complex but the useful
ones will lead to simpler explanations.
as the notion of computation is only a short step beyond discrete
mathematics, but opens up vast new territories of questions
and technologies, these new metaphors might well be just a
few steps beyond where we are now in understanding organizational
dynamics, but they may have rich and far reaching implications
in our abilities to understand the natural world and to engineer
Biologist, Rutgers University; Coauthor, Genes
In Conflict: The Biology of Selfish Genetic
Science of Self-deception Requires a Deep Understanding
I first saw the possibility (some 30 years ago) of grounding
a science of human self-deception in evolutionary logic (based
on its value in furthering deception of others), I imagined
joining evolutionary theory with animal behavior and with those
parts of psychology worth preserving. The latter I regarded
as a formidable hurdle since so much of psychology (depth and
social) appeared to be pure crap, or more generously put, without
any foundation in reality or logic.
after a couple of years of intensive study of the subject,
I am surprised at the number of areas of biology that
are important, if not key, to the subject yet are relatively
undeveloped by biologists. I am also surprised that many of
the important new findings in this regard have been made by
psychologists and not biologists.
was always obvious that when neurophysiology actually became
a science (which it did when it learned to measure on-going
mental activity) it would be relevant to deceit and self-deception
and this is becoming more apparent every day. Also, endocrinology
could scarcely be irrelevant and Richard Wrangham has recently
argued for an intimate connection between testosterone and
self-deception in men but the connections must be much deeper
still. The proper way to conceptualize the endocrine system
(as David Haig has pointed out to me) is as a series of signals
with varying half-lives which give relevant information to
organs downstream and many such signals may be relevant to
deceit and self-deception and to selves-deception,
as defined below.
thing I never imagined was that the immune system would be
a vital component of any science of self-deception, yet two
lines of work within psychology make this clear. Richard Davidson
and co-workers have shown that relatively positive, up, approach-seeking
people are more likely to be left-brain activated (as measured
by EEG) and show stronger immune responses to a novel challenge
(flu vaccine) than are avoidance, negative emotion (depression,
anxiety) right-brained people. At the same time, James
Pennebaker and colleagues have shown that the very act of repressing
information from consciousness lowers immune function while
sharing information with others (or even a diary) has the opposite
effect. Why should the immune system be so important and why
should it react in this way?
key variable in my mind is that the immune system is an extremely
expensive one—we produce a grapefruit-sized set of tissue
every two weeks—and we can thus borrow against it, apparently
in part for brain function. But this immediately raises the
larger question of how much we can borrow against any given
system—yes fat for energy, bone and teeth when necessary
(as for a child in utero), muscle when not used and so on—but
with what effects? Why immune function and repression?
genetics is, in principle, important to all of biology, I thought
it would be irrelevant to the study of self-deception until
way into the distant future. Yet the 1980s produced the striking
discovery that the maternal half of our genome could act against
the paternal, and vice-versa, discoveries beautifully exploited
in the 90’s and 00’s by David Haig to produce a
range of expected (and demonstrated) internal conflicts which
must inevitably interact with self-deception directed toward
others. Put differently, internal genetic conflict leads to
a quite novel possibility: selves-deception, equally
powerful maternal and paternal halves selected to deceive each
other (with unknown effects on deception of others).
consider one of the great mysteries of mental biology. The
human brain consumes about 20% of resting metabolic rate come
rain or shine, whether depressed or happy, asleep or awake.
Why? And why is the brain so quick to die when deprived of
this energy? What is the cellular basis for all of this? How
exactly does borrowing from other systems, such as immune,
interact with this basic metabolic cost? Biologists have been
very slow to see the larger picture and to see that fundamental
discoveries within psychobiology require a deeper understanding
of many fundamental biological processes, especially the logic
of energy borrowed from various sources.
let me express a surprise about psychology. It has led the
way in most of the areas mentioned, e.g. immune effects, neurophysiology,
brain metabolism. Also, while classical depth psychology (Freud
and sundries) can safely be thrown overboard almost in its
entirety, social psychology has produced some very clever and
hopeful methods, as well as a body of secure results on biased
human mentation, from perception, to organization of data,
to analysis, to further propagation. Daniel Gilbert gives a
well-appreciated lecture in which he likens the human mind
to a bad scientist, everything from biased exposure to data
and biased analysis of information to outright forgery. Hidden
here is a deeper point. Science progresses precisely because
it has a series of anti-deceit-and-self-deception devices built
into it, from full description of experiments permitting exact
replication, to explicit statement of theory permitting precise
counter-arguments, to the preference for exploring alternative
working hypothesis, to a statistical apparatus able to weed
out the effects of chance, and so on.
of Geography, UCLA
year 2007 marked three memorable events in climate science: Release
of the Fourth Assessment Report of the Intergovernmental Panel
on Climate Change (IPCC AR4); a decade of drought in the American
West and the arrival of severe drought in the American Southeast;
and the disappearance of nearly half of the polar sea-ice floating
over the Arctic Ocean. The IPCC report (a three-volume, three-thousand
page synthesis of current scientific knowledge written for
policymakers) and the American droughts merely hardened my
conviction that anthropogenic climate warming is real and just
getting going — a view shared, in the case of the IPCC,
a few weeks ago by the Nobel Foundation. The sea-ice collapse,
however, changed my mind that it will be decades before we
see the real impacts of the warming. I now believe they will
happen much sooner.
put the 2007 sea-ice year into context. In the 1970's, when
NASA first began mapping sea ice from microwave satellites,
its annual minimum extent (in September, at summer's end) hovered
close to 8 million square kilometers, about the area of the
conterminous United States minus Ohio. In September 2007 it
dropped abruptly to 4.3 million square kilometers, the area
of the conterminous United State minus Ohio and all the other
twenty-four states east of the Mississippi, as well as North
Dakota, Minnesota, Missouri, Arkansas, Louisiana, and Iowa.
Canada's Northwest Passage was freed of ice for the first time
in human memory. From Bering Strait where the U.S. and Russia
brush lips, open blue water stretched almost to the North Pole.
makes the 2007 sea-ice collapse so unnerving is that it happened
too soon. The ensemble averages of our most sophisticated
climate model predictions, put forth in the IPCC AR4 report
and various other model intercomparison studies, don't predict
a downwards lurch of that magnitude for another fifty years.
Even the aggressive models -the National Center for Atmospheric
Research (NCAR) CCSM3 and the Centre National de Recherches
Meteorologiques (CNRM) CM3 simulations, for example — must
whittle ice until 2035 or later before the 2007 conditions
can be replicated. Put simply, the models are too slow
to match reality. Geophysicists, accustomed to non-linearities
and hard to impress after a decade of 'unprecedented' events,
are stunned by the totter: Apparently, the climate system
can move even faster than we thought. This has decidedly
recalibrated scientist's attitudes — including my own — to
the possibility that even the direst IPCC scenario predictions
for the end of this century — 10 to 24 inch higher global
sea levels, for example — may be prudish.
does all this say to us about the future? The first is that
rapid climate change — a nonlinearity that occurs when
a climate forcing reaches a threshold beyond which little additional
forcing is needed to trigger a large impact — is a distinct
threat not well captured in our current generation of computer
models. This situation will doubtless improve
— as the underlying physics of the 2007 ice event and others
such as the American Southeast drought are dissected, understood,
— but in the meantime, policymakers must work from the
IPCC blueprint which seems almost staid after the events of this
summer and fall. The second is that it now seems probable
that the northern hemisphere will lose its ice lid far sooner
than we ever thought possible. Over the past three years
experts have shifted from 2050, to 2035, to 2013 as plausible
dates for an ice-free Arctic Ocean — estimates at first
guided by models then revised by reality.
broader significance of vanishing sea ice extends far beyond
suffering polar bears, new shipping routes, or even development
of vast Arctic energy reserves. It is absolutely unequivocal
that the disappearance of summer sea ice — regardless
of exactly which year it arrives — will profoundly alter
the northern hemisphere climate, particularly through amplified
winter warming of at least twice the global average rate. Its
further impacts on the world's precipitation and pressure systems
are under study but are likely significant. Effects both positive
and negative, from reduced heating oil consumption to outbreaks
of fire and disease, will propagate far southward into the
United States, Canada, Russia and Scandinavia. Scientists have
expected such things in eventuality — but in 2007 we
learned they may already be upon us.
of Molecular Biology and Public Policy, Woodrow
Wilson School, Princeton; Author, Challenging
"If we could just get people to understand
the science, they'd agree with us." Not.
an interview with the New York Times, shortly before
he died, Francis Crick told a reporter, "the view of
ourselves as [ensouled] 'persons' is just as erroneous as
the view that the Sun goes around the Earth. This sort of
language will disappear in a few hundred years. In the fullness
of time, educated people will believe there is no soul independent
of the body, and hence no life after death."
the vast majority of academic scientists and philosophers alive
today, I accept Crick's philosophical assertion — that
when your body dies, you cease to exist — without any
reservations. I also used to agree with Crick's psychosocial
prognosis — that modern education would inevitably give
rise to a populace that rejected the idea of a supernatural
soul. But on this point, I have changed my mind.
Crick's psychosocial claim is a common assumption: the minds
of all intelligent people must operate according to the same
universal principles of human nature. Of course, anyone who
makes this assumption will naturally believe that their own
mind-type is the universal one. In the case of Crick and most
other molecular biologists, the assumed universal mind-type
is highly receptive to the persuasive power of pure logic and
upon a time, my own worldview was similarly informed. I was
convinced that scientific facts and rational argument alone
could win the day with people who were sufficiently intelligent
and educated. To my mind, the rejection of rational thought
by such people was a sign of disingenuousness to serve political
or ideological goals.
mind began to change one evening in November 2003. I had given
a lecture at small liberal arts college along with a member
of The President's Council on Bioethics, whose views on
human embryo research are diametrically opposed to my own.
Surrounded by students at the wine and cheese reception that
followed our lectures, the two of us began an informal debate
about the true meaning and significance of changes in gene
expression and DNA methylation during embryonic development.
Six hours later, long after the last student had crept off
to sleep, it was 4:00 am, and we were both still convinced
that with just one more round of debate, we'd get the other
to capitulate. It didn't happen.
this experience, I have purposely engaged other well-educated
defenders of the irrational, as well as numerous students at
my university, in spontaneous one-on-one debates about a host
of contentious biological subjects including evolution, organic
farming, homeopathy, cloned animals, "chemicals" in
our food, and genetic engineering. Much to my chagrin, even
after politics, ideology, economics, and other cultural issues
have been put aside, there is often a refusal to accept scientific
implications of rational argumentation.
its mode of expression may change over cultures and time, irrationality
and mysticism seem to be an integral part of normal human nature,
even among highly educated people. No matter what scientific
and technological advances are made in the future, I now doubt
that supernatural beliefs will ever be eradicated from the
New York University; Author, The Birth of the Mind
Special About Human Language
I was in graduate school, in the early 1990s, I learned two
important things: that the human capacity for language was
innate, and that the machinery that allowed human beings to
learn language was "special", in the sense of being
separate from the rest of the human mind.
ideas sounded great at the time. But (as far as I can tell
know) only one of them turns out to be true.
still think that I was right to believe in "innateness",
the idea that the human mind, arrives, fresh from the factory,
with a considerable amount of elaborate machinery. When a human
embryo emerges from the womb, it has almost all the neurons
it will ever have. All of the basic neural structures are already
in place, and most or all of the basic neural pathways are
established. There is, to be sure, lots of learning yet to
come — an infant's brain is more rough draft than final
product — but anybody who still imagines the infant human
mind to be little more than an empty sponge isn't in touch
with the realities of modern genetics and neuroscience. Almost
half our genome is dedicated to the development of brain function,
and those ten or fifteen thousand brain-related genes choreograph
an enormous amount of biological sophistication. Chomsky
(whose classes I sat in on while in graduate school) was absolutely
right to be insisting, for all these years, that language has
its origins in the built-in structure of the mind.
now I believe that I was wrong to accept the idea that language
was separate from the rest of the human mind. It's always been
clear that we can talk about what we think about, but when
I was in graduate school it was popular to talk about language
as being acquired by a separate "module" or "instinct" from
the rest of cognition, by what Chomsky called a "Language
Acquisition Device" (or LAD). Its mission in life was
to acquire language, and nothing else.
keeping with idea of language as product of specialized in-born
mechanism, we noted how quickly how human toddlers acquired
language, and how determined they were to do so; all normal
human children acquire language, not just a select few raised
in privileged environments, and they manage to do so rapidly,
learning most of what they need to know in the first few years
of life. (The average adult, in contrast, often gives
up around the time they have to face their fourth list of irregular
verbs.) Combine that with the fact that some children
with normal intelligence couldn't learn language and that others
with normal language lacked normal cognitive function, and
I was convinced. Humans acquired language because they had
a built-in module that was uniquely dedicated to that function.
so I thought then. By the late 1990s, I started looking beyond
the walls of my own field (developmental psycholinguistics)
and out towards a whole host of other fields, including genetics,
neuroscience, and evolutionary biology.
idea that most impressed me — and did the most to shake
me of the belief that language was separate from the rest of
the mind — goes back to Darwin. Not "survival of
the fittest" (a phrase actually coined by Herbert Spencer)
but his notion, now amply confirmed at the molecular level,
that all biology is the product of what he called "descent
with modification". Every species, and every biological
system evolves through a combination of inheritance (descent)
and change (modification). Nothing, no matter how original
it may appear, emerges from scratch.
I ultimately realized, must be no different: it emerged quickly,
in the space of a few hundred thousand years, and with comparatively
little genetic change. It suddenly dawned on me that the striking
fact that our genomes overlap almost 99% with those of chimpanzees
must be telling something: language couldn't possibly have
started from scratch. There isn't enough room in the genome,
or in our evolutionary history, for it to be plausible that
language is completely separate from what came before.
I have now come to believe, language must be, largely, a recombination
of spare parts, a kind of jury-rigged kluge built largely out
of cognitive machinery that evolved for other purposes, long
before there was such a thing as language. If there's something
special about language, it is not the parts from which it is
composed, but the way in which they are put together.
studies seem to bear this out. Whereas we once imagined language
to be produced and comprehended almost entirely by two purpose-built
regions — Broca's area and Wernicke's area, we now see
that many other parts of the brain are involved (e.g. the cerebellum
and basal ganglia) and that the classic language areas (i.e.
Broca's and Wernicke's) participate in other aspects of mental
life (e.g., music and motor control) and have counterparts
in other apes.
the narrowest level, this means that psycholinguists and cognitive
neuroscientists need to rethink their theories about what language
is. But if there is a broader lesson, it is this: although
we humans in many ways differ radically from any other species,
our greatest gifts are built upon a genomic bedrock that we
share with the many other apes that walk the earth.
Perimeter Institute; Author, The Trouble With Physics
I have changed my mind about several ideas and theories, my
longest struggle has been with the concept of time. The
most obvious and universal aspect about reality, as we experience
it, is that it is structured as a succession of moments, each
of which comes into being, supplanting what was just present
and is now past. But, as soon as we describe nature in
terms of mathematical equations, the present moment and the
flow of time seem to disappear, and time becomes just a number,
a reading on an instrument, like any other.
many philosophers and physicists argue that time is an illusion,
that reality consists of the whole four dimensional history
of the universe, as represented in Einstein’s theory
of general relativity. Some, like Julian Barbour, go
further and argue that, when quantum theory is unified with
gravity, time disappears completely. The world
is just a vast collection of moments which are represented
by the "wave-function of the universe." Time
not real, it is just an "emergent quantity" that
is helpful to organize our observations of the universe when
it is big and complex.
physicists argue that aspects of time are real, such as the
relationships of causality, that record which events were the
necessary causes of others. Penrose, Sorkin and Markopoulou
have proposed models of quantum spacetime in which everything
real reduces to these relationships of causality.
my own thinking, I first embraced the view that quantum
reality is timeless. In our work on loop quantum gravity
we were able to take this idea more seriously than people before
us could, because we could construct and study exact wave-functions
of the universe. Carlo Rovelli , Bianca Dittrich and others
worked out in detail how time would "emerge" from
the study of the question of what quantities of the theory
somehow, the more this view was worked out in detail the less
I was convinced. This was partly due to technical challenges
in realizing the emergence of time, and partly because some
naïve part of me could never understand conceptually how
the basic experience of the passage of time could emerge from
a world without time.
in the late 90s I embraced the view that time, as causality, is
real. This fit best the next stage of development of loop quantum
gravity, which was based on quantum spacetime histories. However, even
as we continued to make progress on the technical side
of these studies, I found myself worrying that
the present moment and the flow of time were still nowhere
represented. And I had another motivation, which was
to make sense of the idea that laws of nature could evolve
in the early 90s I had formulated a view of laws evolving on
a landscape of theories along with the universe they govern. This
had been initially ignored, but in the last few years there
has been much study of dynamics on landscapes of theories.
Most of these are framed in the timeless language of the "wavefunction of
the universe," in contrast to my original presentation,
in which theories evolved in real time. As these studies progressed,
it became clear that only those in which time played a role
could generate testable predictions
— and this made me want to think more deeply about
is becoming clear to me that the mystery of the nature of time
is connected with other fundamental questions such as the nature
of truth in mathematics and whether there must be timeless
laws of nature. Rather than being an illusion, time may be
the only aspect of our present understanding of nature that
is not temporary and emergent.
Theoretical Physicist; Author, "An
Exceptionally Simple Theory of Everything"
Used To Think I Could Change My Mind
a scientist, I am motivated to build an objective model of
reality. Since we always have incomplete information, it is
eminently rational to construct a Bayesian network of likelihoods — assigning
a probability for each possibility, supported by a chain of
priors. When new facts arise, or if new conditional relationships
are discovered, these probabilities are adjusted accordingly — our
minds should change. When judgment or action is required,
it is based on knowledge of these probabilities. This method
of logical inference and prediction is the sine qua non of
rational thought, and the method all scientists aspire to employ.
However, the ambivalence associated with an even probability
distribution makes it terribly difficult for an ideal scientist
to decide where to go for dinner.
though I strive to achieve an impartial assessment of probabilities
for the purpose of making predictions, I cannot consider my
assessments to be unbiased. In fact, I no longer think humans
are naturally inclined to work this way. When I casually consider
the beliefs I hold, I am not readily able to assign them numerical
probabilities. If pressed, I can manufacture these numbers,
but this seems more akin to rationalization than rational thought.
Also, when I learn something new, I do not immediately erase
the information I knew before, even if it is contradictory.
Instead, the new model of reality is stacked atop the old.
And it is in this sense that a mind doesn't change; vestigial
knowledge may fade over a long period of time, but it isn't
simply replaced. This model of learning matches a parable from
Douglas Adams, relayed by Richard Dawkins:
man didn't understand how televisions work, and was convinced
that there must be lots of little men inside the box, manipulating
images at high speed. An engineer explained to him about
high frequency modulations of the electromagnetic spectrum,
about transmitters and receivers, about amplifiers and
cathode ray tubes, about scan lines moving across and down
a phosphorescent screen. The man listened to the engineer
with careful attention, nodding his head at every step
of the argument. At the end he pronounced himself satisfied.
He really did now understand how televisions work. "But
I expect there are just a few little men in there, aren't
humans, we are inefficient inference engines — we are
attached to our "little men," some dormant and some
active. To a degree, these imperfect probability assessments
and pet beliefs provide scientists with the emotional conviction
necessary to motivate the hard work of science. Without the
hope that an improbable line of research may succeed where
others have failed, difficult challenges would go unmet. People
should be encouraged to take long shots in science, since,
with so many possibilities, the probability of something improbable
happening is very high. At the same time, this emotional optimism
must be tempered by a rational estimation of the chance of
success — we must not be so optimistic as to delude ourselves.
In science, we must test every step, trying to prove our ideas
wrong, because nature is merciless. To have a chance of understanding
nature, we must challenge our predispositions. And even if
we can't fundamentally change our minds, we can acknowledge
that others working in science may make progress along their
own lines of research. By accommodating a diverse variety of
approaches to any existing problem, the scientific community
will progress expeditiously in unlocking nature's secrets.
I be thinking about quantum gravity?
of the big problems in physics — perhaps the biggest! — is
figuring out how our two current best theories fit together.
On the one hand we have the Standard Model, which tries to
explain all the forces except gravity, and takes quantum
mechanics into account. On the other hand we have General
Relativity, which tries to explain gravity, and does not
take quantum mechanics into account. Both theories seem to
be more or less on the right track — but until we somehow
fit them together, or completely discard one or both, our
picture of the world will be deeply schizophrenic.
seems plausible that as a step in the right direction we
should figure out a theory of gravity that takes quantum
mechanics into account, but reduces to General Relativity
when we ignore quantum effects (which should be small in
many situations). This is what people mean by "quantum
gravity" — the quest for such a theory.
most popular approach to quantum gravity is string theory. Despite
decades of hard work by many very smart people, it's far
from clear that this theory is successful. It's made no predictions
that have been confirmed by experiment. In fact, it's
made few predictions that we have any hope of testing anytime
soon! Finding certain sorts of particles at the big
new particle accelerator near Geneva would count as partial
confirmation, but string theory says very little about the
details of what we should expect. In fact, thanks to the
vast "landscape" of string theory models that researchers
are uncovering, it keeps getting harder to squeeze specific
predictions out of this theory.
I was a postdoc, back in the 1980s, I decided I wanted to
work on quantum gravity. The appeal of this big puzzle seemed
irresistible. String theory was very popular back then,
but I was skeptical of it. I became excited when I
learned of an alternative approach pioneered by Ashtekar,
Rovelli and Smolin, called loop quantum gravity.
quantum gravity was less ambitious than string theory. Instead
of a "theory of everything", it only sought to
be a theory of something: namely, a theory of quantum gravity.
I jumped aboard this train, and for about a decade I was
very happy with the progress we were making. A beautiful
picture emerged, in which spacetime resembles a random "foam" at
very short distance scales, following the laws of quantum
can write down lots of theories of this general sort. However,
we have never yet found one for which we can show that General
Relativity emerges as a good approximation at large distance
scales — the quantum soap suds approximating a smooth
surface when viewed from afar, as it were.
helped my colleagues Dan Christensen and Greg Egan do a lot
of computer simulations to study this problem. Most of our
results went completely against what everyone had expected. But
worse, the more work we did, the more I realized I didn't
know what questions we should be asking! It's hard
to know what to compute to check that a quantum foam is doing
its best to mimic General Relativity.
this time, string theorists took note of loop quantum gravity
people and other critics — in part thanks to Peter
Woit's blog, his book Not Even Wrong, and Lee Smolin's
book The Trouble with Physics. String theorists
weren't used to criticism like this. A kind of "string-loop
war" began. There was a lot of pressure for physicists
to take sides for one theory or the other. Tempers ran high.
Lanier put it this way: "One gets the impression that
some physicists have gone for so long without any experimental
data that might resolve the quantum-gravity debates that
they are going a little crazy." But even more
depressing was that as this debate raged on, cosmologists
were making wonderful discoveries left and right, getting
precise data about dark energy, dark matter and inflation. None
of this data could resolve the string-loop war! Why? Because
neither of the contending theories could make predictions
about the numbers the cosmologists were measuring! Both theories
were too flexible.
realized I didn't have enough confidence in either theory
to engage in these heated debates. I also realized
that there were other questions to work on: questions where
I could actually tell when I was on the right track, questions
where researchers cooperate more and fight less. So,
I eventually decided to quit working on quantum gravity.
was very painful to do this, since quantum gravity had been
my holy grail for decades. After you've convinced yourself
that some problem is the one you want to spend your life
working on, it's hard to change your mind. But when
I finally did, it was tremendously liberating.
wouldn't urge anyone else to quit working on quantum gravity.
Someday, someone is going to make real progress. When
this happens, I may even rejoin the subject. But for
now, I'm thinking about other things. And, I'm making
more real progress understanding the universe than I ever
Physicist & Writer; Coauthor (with John Archibald Wheeler), Geons,
Black Holes, and Quantum Foam: A Life in Physics
used to believe that the ethos of science, the very nature
of science, guaranteed the ethical behavior of its practitioners.
As a student and a young researcher, I could not conceive
of cheating, claiming credit for the work of others, or
fabricating data. Among my mentors and my colleagues, I
saw no evidence that anyone else believed otherwise. And
I didn't know enough of the history of my own subject to
be aware of ethical lapses by earlier scientists. There
was, I sensed, a wonderful purity to science. Looking back,
I have to count naiveté as among my virtues as a
I have changed my mind, and I have changed it because of
evidence, which is what we scientists are supposed to do.
Various examples of cheating, some of them quite serious,
have come to light in the last few decades, and misbehaviors
in earlier times have been reported as well. Scientists are,
as the saying goes, "only human," which, in my
opinion, is neither an excuse nor an adequate explanation.
Unfortunately, scientists are now subjected to greater competitive
pressures, financial and otherwise, than was typical when
I was starting out. Some — a few — succumb.
do need to teach ethics as essential to the conduct of science,
and we need to teach the simple lesson that in science crime
doesn't pay. But above all, we need to demonstrate by example
that the highest ethical standards should, and often do,
question presupposes a well defined "you", and
an implied ability that is under "your" control
to change your "mind". The "you" I
now believe is distributed amongst others (family friends
, in hierarchal structures,) i.e. suicide bombers, believe
their sacrifice is for the other parts of their "you".
The question carries with it an intention that I believe
is out of one's control. My mind changed as a result of
its interaction with its environment. Why? because it is
a part of it.