Whatever Happened to Cold Fusion?
by David Goodstein
On 6-9 December, 1993, the Fourth International Conference on
Cold Fusion took place on the island of Maui, in Hawaii. It had
all the trappings of a normal scientific meeting. Two hundred
and fifty scientists took part, mostly from the U.S. and Japan
(hence the site in Hawaii), but also a sprinkling from Italy,
France, Russia, China and other countries. More than 150 scientific
papers were presented on subjects such as calorimetry, nuclear
theory, materials and so on. The founders of the field, Stanley
Pons and Martin Fleischmann, were in attendance and were treated
with the deference due their celebrity status. Pons and Fleischmann
carry out their research today in a laboratory built for them
in Nice, on the French Riviera, by TECHNOVA, a subsidiary of
Toyota. At the meeting it was announced that the Japanese trade
ministry, MITI, has committed $30 million over a period of four
years to support research on what was delicately called "New
Hydrogen Energy," including Cold Fusion.
Contrary to appearances, however, this was no normal scientific
conference. Cold Fusion is a pariah field, cast out by the scientific
establishment. Between Cold Fusion and respectable science there
is virtually no communication at all. Cold fusion papers are
almost never published in refereed scientific journals, with
the result that those works don't receive the normal critical
scrutiny that science requires. On the other hand, because the
Cold-Fusioners see themselves as a community under siege, there
is little internal criticism. Experiments and theories tend to
be accepted at face value, for fear of providing even more fuel
for external critics, if anyone outside the group was bothering
to listen. In these circumstances, crackpots flourish, making
matters worse for those who believe that there is serious science
going on here.
The origins of Cold Fusion have been loudly and widely documented
in the press and popular literature. Pons and Fleischmann, fearing
they were about to be scooped by a competitor named Steven Jones
from nearby Brigham Young University, and with the encouragement
of their own administration, held a press conference on March
23, 1989 at the University of Utah, to announce what seemed to
be the scientific discovery of the century. Nuclear fusion, producing
usable amounts of heat, could be induced to take place on a table-top
by electrolyzing heavy water, using electrodes made of palladium
and platinum, two precious metals. If so, the world's energy
problems were at an end, to say nothing of the fiscal difficulties
of the University of Utah. What followed was a kind of feeding
frenzy, science by press conference and e-mail, confirmations
and disconfirmations, claims and retractions, ugly charges and
obfuscation, science gone berserk. For all practical purposes,
it ended a mere 5 weeks after it began, on May 1st, 1989, at
a dramatic session of The American Physical Society, in Baltimore.
Although there were numerous presentations at this session, only
two really counted. Steven Koonin and Nathan Lewis, speaking
for himself and Charles Barnes, all three from Caltech, executed
between them a perfect slam-dunk that cast Cold Fusion right
out of the arena of mainstream science.
Before I go any further in telling this tale, I think I'd
better come clean about my own prejudices (those of us concerned
about the issue of Conflicts of Interest in academic life refer
to this as "disclosure." It's supposed to help protect
us from sin). The Caltech protagonists, Steve Koonin, Nate Lewis
and Charlie Barnes, are not only my faculty colleagues, I count
them all among my personal friends of many years. On the other
hand, there is a player on the other side of this game who is
also one of my oldest personal friends, and who is besides my
long-time scientific collaborator. His story is one that, because
it took place outside of the United States, was largely off the
radar screen of our journalists and popular authors. Nevertheless,
the story is worth telling. It shows at the very least that the
frenzy that began in Utah was not an isolated or unique phenomenon.
My friend, Professor Francesco Scaramuzzi is the head of a
small low-temperature physics research group at a national laboratory
in Frascati (a suburb of Rome) Italy, run by an agency called
ENEA, roughly analogous to our Department of Energy. It is possible
within this agency for a scientist like my friend Franco to be
promoted to the rank of "Dirigente" ("Executive").
The promotion would not change in any substantial way his assignment
or responsibilities, but it would carry with it very substantial
financial rewards and much prestige. Although Franco was certainly
one of the laboratory's more distinguished scientists long before
Cold Fusion appeared on the scene, he had not been awarded this
promotion by 1989, when he was 61 years old. The reason is that,
in the corrupt Italian system that has collapsed only more recently,
these promotions were based on political affiliation more than
scientific accomplishment. For every two Christian Democrats
promoted, there would also be a new Socialist, a Communist, and
someone from one of the smaller parties among the ranks of the
"Dirigente." Franco had not been promoted because he
refused to join a political party in order to advance his professional
career as a scientist. Franco is, in other words, a man of unflinching
integrity.
On the morning of April 18th, 1989, Franco called to warn
me that I would find his picture in the New York Times the next
day (I did). He had just come out of a press conference announcing
the discovery of a new kind of Cold Fusion.
Like scientists everywhere, he had heard of the Utah announcement
and decided to give it a try. He reasoned that electrolysis wasn't
really necessary. It served only to get deuterium (the hydrogen
isotope in heavy water) to insert itself into the atomic lattice
of the palladium electrode. He also thought it necessary that
the system not be in thermodynamic equilibrium. He and his handful
of young scientists and technicians arranged to put some titanium
shavings in a cell pressurized with deuterium gas (titanium is
both cheaper and easier to get hold of than palladium, and like
palladium, it is a metal that absorbs large quantities of hydrogen
or deuterium into its atomic crystal lattice). Then they used
some liquid nitrogen (a refrigerant readily available in any
low-temperature physics laboratory) to run the temperature of
the cell up and down, thus creating thermodynamic disequilibrium.
The crude apparatus was not suitable for the difficult measurement
needed to tell whether any heat was being generated, but fusion
should produce neutrons (that is what Steven Jones had claimed
to detect at BYU). They got a colleague at the Frascati lab to
set up a neutron detector near their apparatus. In the course
of their experiments, they often detected nothing at all, but
on a couple of occasions, their detector indicated very substantial
bursts of neutrons.
When the second positive result was discovered on April 17th,
Franco decided he had to inform the head of his laboratory. In
no time at all, he found himself in downtown Rome, talking about
it to the head of the entire national agency.
The agency ENEA had been without funding for four months.
The necessary legislation was stalled in Parliament. ENEA was
borrowing money from banks to meet its payroll. All purchases
were frozen. Research was paralyzed. To the politically astute
agency head, Scaramuzzi's discovery was an opportunity not to
be missed. Franco agreed to a press conference, but only if he
could give a full technical seminar to his scientific peers first.
The seminar, hastily organized for that same day, was crammed
to the rafters with scientists from every laboratory in the Rome
area, and was even covered by the evening television news programs.
At the press conference the next morning, Franco, stunned to
find himself flanked by two Ministers of State, did his best
to behave with the utmost scientific objectivity and reserve,
but it made not the slightest bit of difference. The story made
headlines all over Italy. Within days, Parliament had approved
financing for ENEA and Franco had been promoted to Dirigente.
The agency was solvent once more, and Franco's personal salary
had increased overnight from one that would be meager for an
American post-doc to one that would be generous for an American
full professor.
He had also become the Italian Prometheus, stealing fire from
the Sun. My very reserved, correct, self-effacing friend was
a media celebrity, suddenly the most famous scientist in Italy.
When I came to visit just a few months later, in the Summer of
1989, he handed me two books, each two or three inches thick,
of Xerox copies of his press notices in Italy and abroad. Although
it happened far off-stage for most Americans, what happened in
Italy had mirrored in many important ways the feeding frenzy
in the United States.
For one thing, pecuniary motives had driven science out of
the laboratory into the blinding glare of publicity. For another,
the story instantly captured the public fancy. Not only were
the gallant scientists about to rescue us from the grips of the
greedy oil barons (the whole affair took place just shortly after
the Exxon Valdez incident), the story was spiced with lots of
delicious ironies. In America, mere chemists, spending money
out of their own pockets, seemed to have succeeded where arrogant
physicists spending hundreds of millions of dollars of public
funds had conspicuously failed: they had produced controlled
nuclear fusion. The chemists had beaten the physicists, little
science had beaten big science, cleverness had prevailed over
brute force, two humble professors from Utah had won out over
the aristocrats of bicoastal, non-Mormon America. (True, the
two Utah professors, Pons and Jones were bitter rivals, Jones,
the only Mormon of the bunch, was a physicist, not a chemist,
and Pon's partner Fleischmann was not only an Englishman, but
an FRS. These were mere footnotes however). Much the same was
true in Italy. The dire straits of ENEA drove the story out of
the lab and into the headlines. Not only had Cold Fusion been
reproduced in Italy, the Italian version was of an entirely new
kind , "Fusione Fredda" or Cold Fusion Italian Style
was "dry fusion" i.e., without electrolysis. True,
Scaramuzzi was also a physicist, not a chemist, but he did small,
clever, low budget science in the Frascati lab, which is better
known for its hot fusion and synchrotron-type big science. Suddenly,
Italy had more to give the world than sunshine and pasta. An
Italian scientific hero strode the world stage (or so it seemed
from inside Italy).
The Cold Fusion story seemed to stand science on its head,
not only because it was played out in the popular press without
the ritual of peer-review, but also because both sides of the
debate violated what are generally supposed to be the central
canons of scientific logic. Science in the 20th century has been
much influenced by the ideas of the Austrian philosopher, Karl
Popper. Popper argues that a scientific idea can never be proven
true, because no matter how many observations seem to agree with
it, it may still be wrong. On the other hand, a single contrary
experiment can prove a theory forever false. Therefore, science
advances only by demonstrating that theories are false, so that
they must be replaced by better ones. The proponents of Cold
Fusion took exactly the opposite view: many experiments, including
their own, failed to yield the expected results. These were irrelevant,
they argued, incompetently done, or lacking some crucial (perhaps
unknown) ingredient needed to make the thing work. Instead, all
positive results, the appearance of excess heat, or a few neutrons,
proved the phenomenon was real. This anti-Popperian flavor of
Cold Fusion played no small role in its downfall, since seasoned
experimentalists like Lewis and Barnes refused to believe what
they couldn't reproduce in their own laboratories. To them, negative
results still mattered.
On the other hand, the anti-Cold Fusion crowd was equally
guilty, if you believe another of the solemn canons: It is said
in all the high school textbooks that science must be firmly
rooted in experiment or observation, unladen with theoretical
preconceptions. On the contrary, however, the failure of Cold
Fusion was due, above all, to the fact that it was an experiment
whose result was contrary to prevailing theory.
All parties agreed that, if Cold Fusion occurred in the experiments
of Pons and Fleischmann, Jones, Scaramuzzi and many others, the
primary event would have to have been the fusion of the two deuterium
nuclei: Deuterium nuclei repel one another because of the electric
force between them, but if they get close enough together they
fuse anyway because of what is called the "strong"
(nuclear) force. The laws of quantum mechanics allow deuterium
nuclei to fuse by accident every so often even if they are not
initially close together, but the probability of that happening
is very small. Suppose, for example, they are as far apart as
the two deuterium nuclei normally are in a deuterium molecule.
Then the probability of fusion is much too small to have produced
the alleged effects claimed by the Cold Fusioners. There are
two ways to look at just how small the probability is. At the
inter-nuclear spacing in the deuterium molecule, the probability
is too small by forty or fifty orders of magnitude. Physicists
love to throw around phrases like that one. An order of magnitude
means a factor of ten. Too small by forty or fifty orders of
magnitude really means too small beyond discussion, beyond imagination,
almost beyond meaning. On the other hand, that probability is
insanely sensitive to how far apart the nuclei are to begin with.
To increase the probability by the requisite 40 or 50 orders
of magnitude requires getting the nuclei closer together by just
one order of magnitude. It is extremely difficult to imagine
how -- given the well-known forces involved -- they can be gotten
closer together by a factor of ten in an experiment on a table-top.
In fact, the whole purpose of the hundreds of millions of dollars
spent on hot fusion is to produce exactly that result. Nevertheless,
once we have been anesthetized by talking about 40 or 50 orders
of magnitude, the idea that a one order of magnitude gap might
somehow be overcome is not so hard to swallow.
Still the theoretical difficulties of Cold Fusion don't end
with getting the nuclei somehow to fuse. When two deuterium nuclei
fuse, they momentarily form the nucleus of the common isotope
of helium, called helium-4. When that happens, however, there
is so much excess energy in the reaction that the helium-4 almost
always breaks up immediately into two smaller pieces. About half
the time, a neutron pops out, leaving a helium-3 nucleus. The
other half the time, a proton comes off, leaving a hydrogen-3,
also known as tritium, nucleus. It also happens that, one time
in a million, the helium-4 doesn't break up at all. Instead,
an intact helium-4 nucleus goes zooming off, while emitting a
powerful gamma-ray photon. In all cases, the two pieces go off
in opposite directions with lots of energy.
What you expect, then, is that about half the fusions will
produce energetic neutrons, and the other half will leave behind
tritium as evidence they occurred. In fact, as we have already
seen, neutrons were detected by Jones, Scaramuzzi and others,
and offered as evidence for Cold Fusion, but there were always
far too few of them to account for the amount of heat being claimed
by Pons and Fleischmann (the heat would presumably be the end-product
of the energy carried away by the nuclear fragments of the various
reactions that could take place). In fact, on the evening of
the original Pons and Fleischmann press conference, I ran into
one of my buddies at Caltech, a battle-scarred veteran of experimental
nuclear physics. "What do you think?" I asked (there
was no need to be more specific). "It's bullshit,"
he said, slipping immediately into technical jargon "if
it were true, they'd both be dead." What he meant was that
if enough fusions had taken place to produce the amount of heat
claimed by Pons and Fleischmann, the flux of neutrons that resulted
would have long since been enough to send them both to the happy
hunting grounds.
To believe that Pons and Fleischmann, Jones and Scaramuzzi
and many others who claimed to observe either heat or neutrons
or tritium were all observing the same phenomenon, one must believe
that, when fusion occurs inside a piece of metal, such as palladium
or titanium, the outcome is radically different from what is
known to happen when fusion occurs in the Sun, or in a hot fusion
plasma, or an atomic bomb, or a nuclear accelerator. In other
words, it is different from conventional nuclear physics. Let's
call the three possible outcomes of fusion a, b, and c. We'll
call a the one that emits neutrons, b the one that leaves tritium
behind, and c the one where the helium-4 stays intact. In conventional
nuclear physics, fusion results about half the time in a, half
the time in b, and one millionth of the time in c. To account
for the observations reported, with some consistency, by various
researchers in Cold Fusion, fusion inside a metal would nearly
always result in reaction c (without, however, emitting a gamma
ray). One in every hundred-thousand or so reactions would result
in b, and the probability of a reaction a would be smaller by
yet another factor of a hundred thousand. These are the conditions
needed to explain why Cold Fusion cells can generate power at
the rate of watts, for periods of days or months, while, far
short of killing Pons and Fleischmann, still yield barely detectable
traces of neutrons, and only tiny amounts of tritium.
Is it plausible that the nuclear reaction might be altered
radically when it takes place among the atoms in a metal, rather
than in a rarefied atmosphere? The answer, quite simply, is no.
For one thing, the atomic nucleus is so small compared to the
distances between atoms in a metal that for all practical purposes,
the nucleus is always in a near vacuum. For another thing, events
occur so quickly in the nuclear fusion reaction that the metal
is simply unable to respond. If you like orders of magnitude,
the fastest anything can happen in a metallic crystal is nine
orders of magnitude slower than the typical time in which the
nucleus created by fusing deuterium plays out its drama of fusion
and break-up. In other words, when the nucleus is doing its thing,
the atoms of the crystal are far away and frozen in time. Finally,
the energy released in the nuclear reaction is so large that
the crystal has no means to absorb it, unless it is spread out
instantaneously, over vast distances, by some mechanism not now
known (presumably, the same mechanism would have to account for
why no gamma ray is emitted). In short, according to everything
we know about the behavior of matter and nuclei, Cold Fusion
is impossible. This is what I meant when I said that Cold Fusion
is an experiment whose result is contrary to prevailing theory.
In spite of all that, scientists are aware that they must
be prepared, from time to time, to be surprised by a phenomenon
they previously thought to be impossible. There are two recent
examples that seem relevant to Cold Fusion. One is called High
Temperature Superconductivity, and the other is called the Mössbauer
Effect.
In 1986, two Swiss physicists, J. Georg Bednorz and A. Karl
Mueller announced the discovery of a material that remained superconducting
at temperatures as high as 30 kelvins. Superconductivity is itself
a phenomenon that violates the trained intuition of physicists:
at sufficiently low temperature, many metals can conduct electricity
without any resistance at all, while simultaneously expelling
completely any applied magnetic field. This behavior is so bizarre
that it took nearly half a century after its discovery in 1911
before an acceptable theoretical explanation was formulated.
However, if Nature was going to play such weird tricks on us,
at least they were confined to the privacy of the physics laboratory
by the requirement of extreme low temperature. Before Bednorz
and Mueller, it was well known that superconductivity could never
exist at a temperature higher than 35 kelvins. After Bednorz
and Mueller, it was a matter only of months before materials
were discovered that remained superconducting up to 100 kelvins.
That's still pretty cold -- normal room temperature is about
300 kelvins -- but the shocking impact of that discovery on the
scientific community is hard to overestimate. The discovery of
High Temperature Superconductivity in 1986 set the stage for
the announcement -- and at least temporary acceptance of the
possibility -- of Cold Fusion in 1989.
The Mössbauer Effect, discovered thirty years earlier,
was another completely unexpected phenomenon that seemed to have
an even more direct bearing on Cold Fusion. As we've already
seen, Cold Fusion is hard to swallow in part because it is so
implausible to believe that a nuclear reaction might be altered
in any meaningful way by taking place in a crystal. Yet the Mössbauer
Effect was an example in which precisely that does seem to occur.
When a nucleus has too much energy, it must find some means
to get rid of the excess. For example, we've already seen that
when two deuteriums fuse, the resulting nucleus, which has far
too much energy, can actually break up in any of three ways.
In all three cases, however, the result is two fragments that
fly off in opposite directions. Mössbauer's discovery
was that, in certain cases when a nucleus in a crystal gives
up its excess energy by emitting a gamma ray photon, instead
of the photon going one way and the nucleus the other way as
would normally be expected, there is a substantial probability
that the photon will fly off and the nucleus will stand still.
Instead of the nucleus recoiling (just as a rifle does when it
fires a bullet) the recoil is taken up by the entire crystal,
resulting in essentially no motion at all. The net result is
that the gamma ray photon emitted by a nucleus in a crystal can
have slightly more energy than the gamma ray photon the same
nucleus would have emitted in a vacuum. Our carefully trained
intuition, which says that nuclei are unaffected by being in
a crystal because they exist in entirely separate realms of distance,
time and energy, has been violated. If our intuition can be violated
by the Mössbauer Effect, then why not by Cold Fusion?
That's a good question, and there are very good answers. First,
the Mössbauer Effect can be observed only for a few
special nuclear reactions in which the energy that must be disposed
of is much smaller, and the time the nucleus takes to get rid
of it much larger than in the Cold Fusion reaction. In other
words, it occurs precisely in those special cases where our argument,
that the nucleus and the crystal act on incompatible scales of
time and energy, no longer holds true. Second, even then, the
Mössbauer Effect does not change the intimate details
of the nuclear reaction, such as whether it emits a gamma ray
photon, or the probabilities of the various possible ways of
giving its excess energy up. It is precisely these details that
must be changed if Cold Fusion is real. Finally, the Mössbauer
Effect is in a sense the exact opposite of what is supposed to
happen in Cold Fusion: instead of the nuclear recoil energy somehow
turning into heat in the atomic lattice, the Mössbauer
Effect is interesting precisely because it's the special case
in which no heat at all is produced.
Nevertheless, in spite of all the differences, many scientists
instantly thought of the Mössbauer Effect when they
first heard of Cold Fusion. The discovery of the Mössbauer
Effect had been unexpected, but once it happened, it was quickly
and satisfactorily explained within the framework of conventional
theory. It proved that there are still genuine surprises waiting
for us that, once understood, don't violate conventional physical
laws. And it also proved that there is at least some realm in
which nuclear physics and solid state physics affect one another.
Those are just the things you have to be willing to believe in
order to be prepared to accept Cold Fusion, at least provisionally.
In any case, immediately after the press conference in Utah,
most scientists were willing at least to suspend judgment for
a while, to give Cold Fusion a chance. It was precisely during
this crucial probationary period (so to speak) that Cold Fusion
science went berserk. Many scientists tried their own hand at
it. Those that succeeded, or seemed to succeed, held press conferences.
Those that failed generally quietly let the matter drop and went
on to other things. It would be difficult to devise a worse way
of doing science. Among the exceptions to that behavior were
Lewis, Barnes and Koonin of Caltech. They pursued every lead
with relentless tenacity and Popperian rigor, repeating every
experiment, calculating every effect, looking not merely for
positive or negative results, but also for explanations of the
false positive results that others were reporting -- in other
words, finding the mistakes of other scientists. These they found
in abundance. Far from publicizing their work, they were so secretive
that rumors started to circulate, and even appeared in the press,
that they were protecting positive results. Finally, they were
able, 5 weeks after the Utah press conference, to stand before
their colleagues in Baltimore and, piece by piece, in vivid detail,
demolish the case for Cold Fusion. Cold Fusion had been given
its chance, a suspension of disbelief no matter how unlikely
it seemed, and it had failed to prove itself. Cold Fusion was
dead in the eyes of respectable science.
Meanwhile, back in Frascati, Franco Scaramuzzi and his group
of young researchers were not quite prepared to give up. Just
as the drama in Italy was little noticed in America, events in
Baltimore seem far away when you are in Rome. Franco himself
had had, not just 15 minutes of fame, but a month of it, and
it showed no signs of letting up. He was a hero, not only to
the general public, but also to all his colleagues in the agency
ENEA, and ENEA itself had suddenly shed it's reputation for bumbling
bureaucratic ineptitude. This was not a propitious moment to
throw in his hand, just because Lewis, Barnes and Koonin didn't
approve.
Besides, he had his own data, and he believed in them. Nothing
convinces a scientist nearly as effectively as the experience
of seeing data emerge from one's own experiment. In this case
there were, to be sure, many questions. It turns out that neutrons
are not so easy to detect. The instruments used to detect them
are sometimes tricky and undependable. In the aftermath of the
Frascati announcements, experts from Italy and abroad (especially
the U.S.) made brief visits to Scaramuzzi's lab and pronounced
their verdicts on how the mistake had been made: the apparent
bursts of neutrons were really artifacts due to changes in temperature,
or humidity, or power surges on the (notoriously unstable) Frascati
lab electric system, or other electronic problems. I remember
during my visit that summer talking to one of Franco's young
colleagues, Antonella De Ninno. "Do they think we're stupid?"
she asked me angrily, "of course we thought of all those
possibilities and eliminated them!" Once the group was convinced
they had seen the real thing, they weren't about to give up because
someone had made a speech in Baltimore.
There was also a bit of wriggle-room available. At the Baltimore
meeting, Pons and Fleischmann did not attend, but Jones did,
and he was the first speaker. He pointed out just how small was
the effect he claimed to see compared to what Pons and Fleischmann
were claiming (as we have seen, the number of neutrons that come
out appears to be smaller than expected by about ten orders of
magnitude). Thus it seemed possible that even if Cold Fusion
didn't produce heat (the Pons-Fleischmann claim) maybe something
was going on at a much lower level, producing a few neutrons
(as Jones, and Scaramuzzi among others claimed). Of course, Barnes
at Caltech had shown there were no neutrons just as effectively
as Lewis had shown there was no heat (and Koonin had shown there
was no theory), and furthermore, if Cold Fusion merely produced
a few neutrons instead of a lot of heat it certainly wasn't going
to solve the world's energy problems. Nevertheless, it seemed
at the time that there just might be two kinds of Cold Fusion,
the bad kind (heat) that Koonin and Lewis had put to rest, and
the good kind (neutrons) that was still scientifically respectable.
The Italian press made much of the fact that "Italian Cold
Fusion" was of the good kind, not noticing that the good
kind of Cold Fusion, if it existed, would be a scientific curiosity,
not an epochal discovery.
In any case, after the furor died down, Cold Fusion research
continued in a number of places. The key to continued research
is financial; to paraphrase California politician Jesse Unruh,
money is the mother's milk of scientific research. In the United
States, the government funding agencies quickly fell into line
with scientific orthodoxy and ceased funding anything that smacked
of Cold Fusion. However, the industry-supported Electric Power
Research Institute decided to put up some funds, just in case.
In Japan, Toyota and MITI, apparently willing to accept some
short term risk in exchange for the possibility of a big payoff
later, agreed to put up a few yen. In Italy, ENEA, with its budget
and prestige resting on Cold Fusion, could hardly refuse to permit
Scaramuzzi and his group to press on. In other places, where
scientists were given modest financial support and some discretion
in how to spend it, some chose to pursue Cold Fusion. In spite
of the disapproval of the world-wide scientific establishment,
some Cold Fusion research kept right on going.
Scaramuzzi's group did not devote all of its attention to
Cold Fusion. At the same time all this was going on, they also
developed the world's best device for firing frozen pellets of
solid deuterium into the plasma used to create hot fusion. If
hot fusion were ever to produce useful energy, this is the means
by which the reactor's deuterium fuel would be replenished. They
were also responsible for the sophisticated cooling device that
rendered it possible to make observations of infrared cosmic
radiation in outer space, using relatively inexpensive long range
balloon flights instead of satellites to rise above most of the
Earth's atmosphere. In both of these tasks, they were doing successful
high technology in the very center of the scientific mainstream.
But they did also continue to pursue Cold Fusion. Reacting
to criticism of the primitive technique they had used to detect
neutrons, they purchased the best neutron detection system in
the world, essentially identical to the one used by Charlie Barnes
at Caltech. Going one better, they installed it in physics laboratories
that had been excavated under a mountain called the Gran Sasso,
a two-hour drive from Rome. Anywhere on the surface of the Earth,
there are always some neutrons buzzing around due to cosmic radiation
from outer space. This so-called "background" has to
be subtracted from the neutrons produced by any other phenomenon
such as Cold Fusion. In the galleries under the Gran Sasso, the
shielding effect of the mountain reduces the cosmic ray neutron
background nearly to zero. That's why the laboratory was built
there. An automated system was set up to monitor the neutron
counter while running the temperature of a Scaramuzzi-type deuterium
gas cell up and down. Every week or so, a member of the group
would have to drive out to the Gran Sasso lab, check out the
counters, replenish the supply of liquid nitrogen, and bring
back the data. No one could accuse them any longer of being unsophisticated
about neutron work. However, this experiment, like their own
earlier work and many others blossoming around the world, produced
positive results, but only sporadically. There was no dependable
recipe for coaxing bursts of neutrons out of the Cold Fusion
cell. As long as that was true the world of respectable science
was not going to pay any attention even to the "good kind"
of Cold Fusion.
Then they decided to pursue the "bad kind" as well.
They built a well- designed electrolysis cell, capable of detecting
excess heat if any were produced, while obviating some of the
shortcomings for which previous excess heat experiments had been
criticized. In 1992 and 1993, these experiments, too, gave positive
results. The cell would produce very substantial amounts of heat
(a few watts) for periods of tens of hours at a time. As in the
neutron experiments, these episodes were sporadic, occurring
seemingly at random, but at least they occurred only when the
fluid in the cell was heavy water (containing deuterium), never
when it was light water (containing ordinary hydrogen). The lack
of this kind of control experiment had been one of the points
of criticism of Pons and Fleischmann. However, by this time,
the world of mainstream science was no longer listening.
I went to visit my friend Franco in December 1993, when he
returned from the Maui conference. While I was there, he summarized
the results of the conference in a seminar presented to the Physics
Faculty at the University of Rome ("La Sapienza," the
first university of Rome. Now there are two more). This was in
itself an unusual event. The Physics Faculty of the University
of Rome today is comparable to the physics department at a good
American state university. For them, inviting Franco to speak
about Cold Fusion was a daring excursion to the fringes of science.
Feeling this was a rare opportunity, Franco prepared his talk
with meticulous care.
At the seminar, Franco's demeanor was subdued, and his presentation
was, as always, reserved and correct. Nevertheless, his message
was an optimistic one for Cold Fusion. In essence (although Franco
didn't say it in these words) each of the criticisms that Nate
Lewis had correctly leveled at the experiments of Pons and Fleischmann
had been successfully countered by new experiments reported at
the conference. Even more important, there was reason to believe
that the magic missing factor, the secret ingredient of the recipe
that accounted for why Cold Fusion experiments only sporadically
gave positive results, might finally have been discovered.
One of the criticisms that Nate had used with telling effect
is that local hot-spots often develop in electrolysis experiments
(Nate is himself an electrochemist, and a consummate experimentalist).
By placing their thermometer at an accidental hot spot, and by
neglecting the elementary precaution of stirring the bath in
their cells, Pons and Fleischmann could easily have fooled themselves
into thinking there was excess heat where none really existed.
To counter this argument, Franco could point to the design of
the cell used by his own Frascati group, which carefully averaged
the temperature of the entire cell, rather than measuring it
at a single point (many other groups had introduced mechanical
stirrers into their cells). Another objection that had been raised
was that, if heat was generated in these experiments, it was
the result of some uninteresting chemical process rather than
being due to nuclear fusion. Chemical processes that generate
heat are not uncommon in electrolysis experiments. The strongest
argument for nuclear fusion (given the near absence of the neutrons
and tritium) was that the amount of heat generated was far too
large to be due to any chemical process. That would be true,
the critics replied, if the chemicals were being generated at
the same time as the heat. However, all of these Cold Fusion
cells had long, dormant periods during which energy was being
pumped in, and no excess heat was being produced. The heat finally
liberated in the "Cold Fusion" episodes might just
have been chemical energy stored up during the dormant periods.
In other words, the cells were not producing more energy than
was being put into them, they were just storing up energy and
releasing it in bursts. Not only would that be much less exciting
than a discovery of controlled nuclear fusion, it also wouldn't
be of much help in our struggle against the oil barons. Now this
argument could be countered as well: there were what appeared
to be very careful experiments in which the total amount of energy
consumed during the dormant periods was minuscule compared to
the amount of heat liberated during the active periods.
Finally, one of the most damaging criticisms of Pons and Fleischmann
was that they had failed to do control experiments. Nuclear fusion
(if it occurred) should only have been possible (if it were possible)
when electrolysis was done in heavy water, made of deuterium.
It should not be possible using ordinary water, made of ordinary
hydrogen. Now many groups, including Franco's, had done the necessary
control experiments, and obtained the necessary confirming results
(no heat in the controls). Unfortunately, other groups reported
that they did observe excess heat in experiments done with ordinary
light water. Franco dutifully reported these results at the Rome
seminar, expressing only muted disapproval ("In my opinion,
these results have not been consolidated," he said).
All of this was much less important than the fact that Cold
Fusion experiments, if they gave positive results at all, gave
them only sporadically and unpredictably. When Bednorz and Mueller
announced the discovery of high-temperature superconductivity
in 1986, no one carped about control experiments, because, once
the recipe was known, any competent scientist could make a sample
and test it and it would work immediately. If, at their press
conference, Pons and Fleischmann had given a dependable recipe
for producing excess heat, they very likely would be Nobel Prizewinners
now (as Bednorz and Mueller are) rather than social outcasts
from the community of scientists. The essential key to the return
of Cold Fusion to scientific respectability is to find the missing
ingredient that would make the recipe work every time.
Experiments done in the U.S. and in Japan, and reported at
the Maui meeting indicate that the missing ingredient may have
been found. In all the various Cold Fusion experiments, the first
step is to load deuterium into the body of metallic palladium.
The issue is how much deuterium gets into the metal. The ratio
of the number of atoms of deuterium in the metal to the number
of atoms of palladium is called x. It turns out, by means of
electrolysis, or by putting the metal in deuterium gas, that
it is rather easy to get x up to the range of about 0.6 or 0.7.
That is already a startlingly high figure. If there are almost
as many deuterium atoms as palladium atoms in the material, the
density of deuterium (a form of hydrogen) is essentially equal
to that of liquid hydrogen rocket fuel, which can ordinarily
exist only at extreme low temperatures. In other words, palladium
(and certain other metals including titanium) soak up almost
unbelievable amounts of hydrogen or deuterium if given the chance.
This is far from a new discovery. However, according to the experiments
reported at Maui, x=0.6 or 0.7 is not enough to produce Cold
Fusion. Both the American and Japanese groups showed data indicating
there is a sharp threshold at x=0.85. Below that value (which
can only be reached with great difficulty and under favorable
circumstances) excess heat is never observed. But, once x gets
above that value, excess heat is essentially always observed,
according to the reports presented at Maui, and recounted by
Franco Scaramuzzi in his seminar at the University of Rome.
The audience at Rome, certainly the senior professors who
were present, listened politely, but they did not hear what Franco
was saying (that much became clear from the questions that were
asked at the end of the seminar, and comments that were made
afterward). If they went away with any lasting impression at
all, it was just the sad realization that a fine scientist like
Franco had not yet given up his obsession with Cold Fusion. They
cannot be blamed. Any other audience of mainstream scientists
would have reacted exactly the same way. If Cold Fusion ever
gains back the scientific respectability that was squandered
in March and April of 1989, it will be the result of a long,
difficult battle that has barely begun.
Recently, I told this story in a Philosophy course we teach
at Caltech called "Ethics of Research." The first question,
when I finished my tale, was, do I believe in Cold Fusion? The
answer is, no. Certainly, I believe quite firmly the theoretical
arguments that say Cold Fusion is impossible. On the other hand,
however, I believe equally firmly in the integrity and competence
of Franco Scaramuzzi and his group of co-workers at Frascati.
I was disturbed when I saw that Franco had gotten caught in the
web of science-by-news conference in April 1989 (although I was
truly pleased that he finally got the long overdue recognition
his agency ENEA owed him), and I was even more distressed when
I learned that Franco and his group had observed excess heat
(the "bad kind" of Cold Fusion). However, I have looked
at their cells, and looked at their data, and it's all pretty
impressive. The Japanese experiment showing that heat nearly
always results when x is greater than 0.85 looks even more impressive
on paper. It seems a particularly elegant, well designed experiment,
at least to the untutored eye of a physicist (what do I know
about electrochemistry?) What all these experiments really need
is critical examination by accomplished rivals intent on proving
them wrong. That is part of the normal functioning of science.
Unfortunately, in this area, science is not functioning normally.
There is nobody out there listening.<P>
I suppose that, if nuclear fusion really does take place whenever
x is greater than 0.85 in palladium, the world of conventional
science will eventually be forced to take notice. If not, then
the whole story I have told you is nothing but a curious footnote
to a bizarre and ugly episode in the history of science. Either
way, I think the story illuminates the inner dynamics of the
scientific enterprise in a way that few other stories have done.
For that reason alone, it may be worth telling.
<I>4/5/94</I>
Cold Fusion
Science
& Mathematics
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Uncle Taz Library
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