http://www.nytimes.com/2008/04/15/science/15risk.html?_r=2&oref=slogin&oref=slogin
Gauging a Collider’s Odds of Creating a Black Hole
By DENNIS OVERBYE
Published: April 15, 2008
In Walker Percy’s “Love in the Ruins,” the protagonist, a doctor and an
inventor, recites what he calls the scientist’s prayer. It goes like this:
“Lord, grant that my work increase knowledge and help other men.
“Failing that, Lord, grant that it will not lead to man’s destruction.
“Failing that, Lord, grant that my article in Brain be published
before the destruction takes place.”
Today we require more than prayers that a scientific experiment will not
lead
to the end of the world. We demand hard-headed calculations. But whom can
we
trust to do them?
That question has been raised by the impending startup of the Large Hadron
Collider. It starts sma****ng protons together this summer at the European
Center for Nuclear Research, or Cern, outside Geneva, in hopes of grabbing
a
piece of the primordial fire, forces and particles that may have existed a
trillionth of a second after the Big Bang.
Critics have contended that the machine could produce a black hole that
could
eat the Earth or something equally catastrophic.
To most physicists, this fear is more science fiction than science fact.
At a
recent open house weekend, 73,000 visitors, without pitchforks or torches,
toured the collider without incident.
Nevertheless, some experts say too much hype and not enough candor on the
part
of scientists about the promises and perils of what they do could
boomerang
into a public relations disaster for science, opening the door for
charlatans
and demagogues.
In a paper published in 2000 with the title “Might a Laboratory Experiment
Destroy Planet Earth?” Francesco Calogero, a nuclear physicist at the
University of Rome and co-winner of the 1995 Nobel Peace Prize for his
work
with the Pugwash conferences on arms control, deplored a tendency among
his
colleagues to promulgate a “leave it to the experts” attitude.
http://www.ingentaconnect.com/content/maney/isr/2000/00000025/00000003/art00006;jsessionid=2gbmj4nhqkdhq.alexandra
“Many, indeed most, of them,” he wrote, “seem to me to be more concerned
with
the public relations impact of what they, or others, say and write, than
in
making sure that the facts are presented with complete scientific
objectivity.”
One problem is that society has never agreed on a standard of what is safe
in
these surreal realms when the odds of disaster might be tiny but the
stakes
are cosmically high. In such situations, probability estimates are often
no
more than “informed betting odds,” said Martin Rees, a Cambridge
University
cosmologist, the astronomer royal and the author of “Our Final Hour.”
Adrian
Kent, also of Cambridge, said in a paper in 2003 reviewing scientists’
failure
to calculate adequately and characterize accurately risks to the public,
that
even the most basic question, “ ‘How improbable does a catastrophe have to
be
to justify proceeding with an experiment?’ seems never to have been
seriously
examined.” http://arxiv.org/abs/hep-ph/0009204v6
Dr. Calogero commented, as did Dr. Kent, in 2000 after a very public
battle on
the safety of another accelerator, the Relativistic Heavy Ion Collider, or
Rhic, at the Brookhaven National Laboratory on Long Island. Dr. Calogero
said
he hoped to apply a gentle pressure on Cern to treat these issues with
seriousness. “A crusade against it is a danger,” he said of the new
collider.
“It would not be based on rational argument.”
Fears about the Brookhaven collider first centered on black holes but soon
****fted to the danger posed by weird hypothetical particles, strangelets,
that
critics said could transform the Earth almost instantly into a dead, dense
lump. Ultimately, independent studies by two groups of physicists
calculated
that the chances of this catastrophe were negligible, based on
astronomical
evidence and assumptions about the physics of the strangelets. One re****t
put
the odds of a strangelet disaster at less than one in 50 million, less
than a
chance of winning some lottery jackpots. Dr. Kent, in a 2003 paper, used
the
standard insurance company method to calculate expected losses to explore
how
stringent this bound on danger was. He multiplied the disaster probability
times the cost, in this case the loss of the global population, six
billion. A
result was that, in actuarial terms, the Rhic collider could kill up to
120
people in a decade of operation.
“Put this way, the bound seems far from adequately reassuring,” Dr. Kent
wrote.
Alvaro de Rujula of Cern, who was involved in writing a safety re****t,
said
extending the insurance formula that way violated common sense. “Applied
to
all imaginable catastrophes, it would result in World Paralysis,” he
wrote.
Besides, the random nature of quantum physics means that there is always a
minuscule, but nonzero, chance of anything occurring, including that the
new
collider could spit out man-eating dragons.
Doomsday from particle physics is part of the culture.
Next year will see the release of the film version of “Angels and Demons,”
the
prequel to Dan Brown’s “DaVinci Code,” in which the bad guys use a Cern
accelerator to gather antimatter for a bomb to blow up the Vatican, and it
includes scenes at Cern.
In Douglas Preston’s “Blasphemy,” a best seller last winter, the operators
of
a giant particle collider in New Mexico find themselves talking to an
entity
that sounds like God before religious fanatics descend on the lab and
destroy
it.
Some physicists, who have been waiting 14 years for the new collider, have
proclaimed in papers and press releases increasingly ambitious and
unlikely
hopes, including proving a long-shot version of string theory by producing
microscopic black holes.
Inevitably, these black holes have taken center stage in the latest round
of
doomsday alarms. Most theorists will say the version of their theory that
predicts black holes is extremely unlikely — though not impossible. But
the
chance that such a black hole would not instantly eva****ate according to a
theory famously propounded by Stephen Hawking in 1974 is even more weirdly
unlikely, the theorists say.
Cern’s most recent safety re****t, in 2003, focused mostly on refuting the
strangelet threat in the hadron collider and devoted just three pages to
black
holes, saying they “do not present a conceivable risk.” It gave no odds.
An
anonymous Cern committee is working on a final, more comprehensive re****t.
Neither Dr. Calogero nor Dr. Rees say they are losing sleep over the
collider.
Some risk is acceptable, even inevitable, in the pursuit of knowledge,
they
say, and they trust the physicists who have built it.
But it would be more reassuring in the long run, as Dr. Kent noted, if
everybody agreed beforehand how much risk is acceptable, before spending
billions of dollars and major political capital.
One popular option to determine acceptable risk is to demand that the
chance
of a man-made disaster be kept below the chance of a natural disaster like
being obliterated by an asteroid. Astronomers estimate that chance as one
in
50 million in any given year.
Of course, thanks to those pesky quantum laws, disaster could come
anytime. Or
not. It could happen that the scientist’s prayer will be answered and your
discovery will indeed lead to knowledge, human happiness and a new killer
ap
for iPhones.
“As in all explorations of uncharted domains, there may be a risk,” Dr.
Rees
wrote, “but there is a hidden cost of saying no.”
2008 The New York Times Company
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