A GLEAM IN GOD'S EYE
Next year, Canada will take part in a $9.5-billion international project to
find
the Higgs boson,
the 'God particle'
that physicists theorize gives mass to matter.
Their exciting search
brings up essential questions about
faith, the universe and existence
Canadian
Globe and Mail: December 25, 2006: MATTHEW HART
If it were not for a subatomic particle known as the Higgs boson, Rudolph
the red-nosed reindeer, the sleigh full of presents and fat old Mr. Claus
himself would not weigh anything at all. They would be matter without mass
and, instead of landing on your roof, might easily just float away into the
Christmas sky, spreading dismay among children everywhere and sending a
generation of scientists back to the drawing board.
The question of why it is that we have mass is one of the uncertainties of
contemporary physics, and a series of breathtaking experiments planned for
the new year, when physicists will create conditions that existed
one-thousandth of a billionth of a second after the Big Bang, is expected to
reveal the tiny particle that accounts for mass. Or not.
The Higgs boson is theoretical: It has never been observed. It was proposed
in the 1960s by Peter Higgs of the University of Edinburgh to account for
mass. It works (if it exists) by setting up a field that permeates space and
affects the other particles of matter, resisting their free passage; this
resistance effectively gives them mass. It is the only subatomic constituent
of what is called the Standard Model of particle physics that has remained
invisible, and scientists would dearly love to know if it is really there.
Now, at last, as festive lights flash and twinkle in the winter air, the
world's physicists are also ablaze, animated by the prospect of laying hands
on the tiny speck known affectionately by a term that places it close to the
origin of Creation: "the God particle."
It is a wily phrase. It suggests a thing that is also an act, a dynamic idea
of something unimaginably small that is also the size of heaven. And it
launches a cascade of speculation that includes fantastic mathematical
precision, causes knowable and unknowable, and the playing field where they
meet.
"There is a sort of cosmic religion among physicists," asserts John
Polkinghorne, a particle physicist, former professor of mathematical physics
at Cambridge University and now a theologian. "I don't say necessarily this
means a belief in a personal God or a Christian God. Einstein, for example,
believed in Spinoza's God -- a sort of pantheistic God. But he said that
when he made his great discoveries, he felt like a child in the presence of
his elders."
Prof. Polkinghorne says many scientists feel "wonderment" at the physical
universe. If so, it matches the mood of anticipation that enlivens the
researchers now preparing to expose the elusive particle at the heart of
matter.
In a series of experiments scheduled to begin late next year, marshalling
7,000 scientists from 54 countries, researchers will take a hammer to the
tiniest constituents of matter. In the front line of this assault is a team
of Canadian physicists. Canada's research on the project dates back 15
years, and the instruments developed are important elements in the campaign
now afoot to scrutinize the titanic forces soon to be unleashed.
The site of the coming apocalypse is a 27-kilometre-long tunnel that begins
30 storeys beneath the western suburbs of Geneva and describes a vast circle
extending into France, following a slowly curving course below the slopes of
the Jura mountains and returning to where it began.
Inside the tunnel and adjoining caverns, the European Organization for
Nuclear Research (CERN) and its fellow participants are assembling the
largest scientific instrument ever built - the Large Hadron Collider.
The $9.5-billion apparatus (a cost shared among participating countries)
will fire protons in opposite directions into the tunnel at high velocities.
Even before the protons enter the tunnel they will meet pieces of Canadian
equipment -- a set of 100 complex magnets developed at TRIUMF, Canada's
subatomic research laboratory on the campus of the University of British
Columbia. Later, the magnets were built in Quebec City, and then installed
at CERN. Their job is to boost the speed of a proton on its way into the
tunnel.
Although the circular tunnel's great length means that the curve is gradual,
the protons will move so fast that powerful forces must guide the particles
down the centre of the tunnel and prevent them from hurtling into the walls.
Thus, another series of magnets will deliver into the tunnel a force equal
to the thrust of a jumbo jet every metre.
When proton hits proton at close to the speed of light, each will have the
impetus of a 400-tonne freight train moving at 190 kilometres an hour. As
the protons annihilate each other, a mist of minute dots of wreckage will
explode from the collision. One of these should be the Higgs boson.
The problem is to catch it. The specks vanish almost as soon as they are
born. Each lasts something less than one thousandth of a nanosecond. Not
only that: There will be 800 million collisions every second, each one
spraying the collider tunnel with a shower of instantly vanishing material.
Obviously it takes a burly piece of kit to sift this subatomic maelstrom.
"We need to collect a sample of several hundred collisions out of 40
million," says Richard Teuscher of the University of Toronto, now attached
to CERN. "And we have just a few millionths of a second to decide whether a
collision has produced something interesting."
Two detector chambers installed in the collider will snatch this
information. One, called the CMS, is a massive contraption of computers and
instruments twice the weight of the Eiffel Tower. It will retrieve 10
million gigabytes of data every year, including the 40 million pictures per
second captured by a pixel detector -- a sort of digital camera from hell.
These sensors, made of thin layers of silicon, will be placed closest to the
collision point where proton smashes into proton. When a particle flies
through them, they signal the computers which tiny pixel on their surface
has been penetrated, pinpointing the exact position of the particle.
So precise is this positioning that scientists can tell whether the particle
originated at the proton-proton collision point or a few millimetres from
it, which would mean that it was the byproduct of another particle.
"A billion protons are colliding every second," says Jim Virdee of Imperial
College London. "We are creating conditions that existed just after the Big
Bang. It's very early in time so it's very high energy.
"We are taking a step that creates 10 times more energy than any previous
experiment. We know that at those energies the Standard Model breaks down,
so we know something is going to happen. We may find particles we've never
seen before. Maybe nature has sorted things out in a way we haven't thought
of."
Because they are probing so far back into the origins of time and matter,
and drawing fundamental conclusions, the physicists need to trust their
data. So there are two teams ransacking the events that happen when the
protons collide. Prof. Virdee's is one. Then there are the Canadians.
"It's just us and 2,000 of our closest friends," says William Trischuk, a
University of Toronto physics professor and director of Canada's Institute
of Particle Physics. The detector that Canadians are working on is called
ATLAS -- an apparatus whose computers fill an underground chamber big enough
to hold the 13-storey physics building on the Toronto campus. Although the
scientists working on both detectors are colleagues, rivalry flourishes.
"Absolutely there's a feeling of competition," Prof. Trischuk says. "We're
at our detector and they're at theirs, 15 kilometres away along the tunnel.
It's a friendly and not-so-friendly competition. They have their system and
we have ours, and we're chasing the same discoveries."
Prof. Trischuk has been stalking the Higgs boson for 16 years, as a staffer
at CERN from 1990 until 1996, and then as a member of the Toronto faculty.
While in Toronto, he conducted his research initially at the Fermi National
Accelerator Laboratory in Chicago, but has since returned his focus to the
ATLAS project at CERN. In that time, Canada's commitment to higher research
has steadily increased, and the country's investment in the ATLAS detector
specifically and the accelerator complex as a whole now totals about
$100-million.
"I'm not the only person coming back to Canada," he says. "Canadian
physicists have been coming home to be involved in this."
The equipment offers a rare opportunity. "The collider is much more powerful
than the one at Fermi. If we don't find the Higgs boson, we'll find
something else."
What else might the team find? One surprise could be black holes. Physicists
have long supposed the universe contains dimensions other than the ones we
are familiar with. In one of those dimensions, gravity may be much stronger
than it is in our reality. If the forces unleashed in the collider should
happen to pry open that dimension, matter could compress into a miniature
black hole.
"You should not deduce that we are ready to build a black hole, and CERN
along with the planet will disappear," says Robert Aymar, head of CERN,
"although this is a letter I receive every week."
But fear of calamity is rare at the site. Eagerness is in the air. Amid such
buoyant moods, it is easy to forget that the last bid to find the Higgs
boson came up empty. Researchers at the previous CERN particle smasher, the
Large Electron Positron Collider, admitted defeat five years ago after
rummaging vainly through their data.
"God particle may not exist," one headline trumpeted.
"It's more likely than not that there is no Higgs," said one disheartened
scientist.
But even then, other physicists were looking ahead to the
Large Hadron Collider, envisioning a wedge that would finally be powerful
enough to jam open Creation. Now, with the first attempt only months away, a
sense of exhilaration is palpable among them. It is as if they stood at the
threshold of discovery, knowing that but a push would swing the door open
and reveal the secrets, heaped in subatomic space like so much treasure.
"With the energies available before, they couldn't find the boson," John
Polkinghorne says. "But this collider will have almost certainly enough
energy to find the particle, if it's there."
At the age of 49, after a distinguished career, Prof. Polkinghorne resigned
his chair in physics at Cambridge and studied for the Anglican priesthood.
Now 76, a Fellow of the Royal Society, a knight and canon theologian of the
diocese of Liverpool, he writes and lectures widely on his conviction that
science and religion are part of the same reality, each in its own way
mapping a shared landscape.
A short, bristling figure with untidy silver hair and a vigorous, intensely
warm manner, Prof. Polkinghorne believes there are higher levels of
causation than those proposed by classical physics.
"In 20th-century physics, it's been discovered that there are intrinsic
unpredictabilities in nature," he says. "Everyone would agree about that.
There's no question about it. There is more going on than simple reductive
physical science will be able to define. And that means there is scope for
the operation of higher causal principles." |
New measurements of top quark mass at Fermilab have
revised estimates for the mass of the Higgs boson. (June 9, 2004)
This is not to say that such higher principles necessarily spell God, nor
does Prof. Polkinghorne believe that the existence of God "can be
demonstrated in a logically coercive way." That said, he does believe in
God, suggesting that God is the most reasonable answer to the question posed
by German mathematician Gottfried Leibniz: Why is there something rather
than nothing?
Prof. Polkinghorne is also seduced by what he calls the fruitfulness of
mathematical beauty.
"When physicists are looking for a new level of theory, it's turned out time
and time again that the equations that work are beautiful. So it's a
principle to look for beautiful equations. Paul Dirac [the quantum-theory
founder and former colleague of Prof. Polkinghorne] hated ugly equations,
and said the history of physics was against them. He made a number of
important discoveries by looking for beautiful equations. He called it 'a
very profitable religion.'
"The physical world is rationally transparent and rationally beautiful, and
that gives science wonderment. You don't see that in the scientific papers,
but scientists talk about it all the time."
"Oh, absolutely," says David Wilkinson, another physicist-turned-theologian.
"Among physicists, there's a sense of beauty in the universe. Einstein said
that the most incomprehensible thing about the universe is that it's
comprehensible. And [Nobel-winning physicist] Richard Feynman talked about
the awe that scientists feel about the universe, and said that for many this
was a religious experience. And Feynman was not a Christian, nor sympathetic
to Christianity."
Prof. Wilkinson, a Fellow of the Royal Astronomical Society, completed his
PhD on the subject of star formation and the chemical evolution of galaxies.
Later, he studied theology at Cambridge and trained for the Methodist
ministry. He is now principal of St. John's College, Durham University,
where he is Wesley Research Lecturer in Theology and Science.
For Prof. Wilkinson, terms such as "God particle" simply reflect the desire
of physicists to express concepts in language that indicates the importance
of the idea.
Yet while the term was coined by a physicist -- Nobel winner Leon Lederman
-- its implications bother some scientists. Robert Orr, a physicist at the
University of Toronto and leader of Canada's ATLAS team, prefers the words
of Stephen Weinberg, himself a Nobel laureate in physics, who wrote that
although it is "almost irresistible for humans to believe that we have some
special relation to the universe," life on Earth "is just a tiny part of an
overwhelmingly hostile universe" destined for a "future extinction of
endless cold or intolerable heat. The more the universe seems
comprehensible, the more it also seems pointless."
Inevitably, even the most cautious phrasing can land a scientist in the
midst of controversy. Robert Jastrow, a theoretical physicist who was
founding director of the U.S. National Aeronautics and Space
Administration's Goddard Institute for Space Studies, was accused of giving
comfort to proponents of the theory of intelligent design simply by saying
that "the curtain drawn over the mystery of Creation will never be raised by
human efforts, at least in the foreseeable future."
"Physicists don't say, 'Let me prove God,' " Prof. Wilkinson says, "only
that there are bigger questions than physics can answer, questions raised by
physics itself, such as 'Why is everything here?' "
If physicists feel wonder when they behold the universe, it cannot be much
more profound than what the rest of us get from beholding physicists. In the
collider project, the apparatus alone challenges the imagination.
Last month, the largest superconducting magnet ever built was tested in its
mountain cave, 100 metres underground. It weighs 100 tonnes and will supply
the magnetic field ATLAS needs to perform its tasks. When powered, it will
produce 21,000 amps, the energy equivalent, in yet another metaphor, of
10,000 cars travelling at 70 kilometres an hour. The magnetic energy is
needed, says Canadian physicist Richard Teuscher, to manage the exploding
particles.
"Once you've collided the protons, the particles shoot out in every
direction," he said. "So you have to identify what they are. The way you
identify them is to bend them in a certain direction. You need a huge amount
of magnetic energy to do that. If one bends in a clockwise direction, for
example, depending on how we've set up the magnet, then we know it's a
positive particle."
Canada's ATLAS team includes about 40 tenured professors, 25 postdoctoral
fellows and 50 graduate students, drawn from 11 universities and several
institutions across the country. As well as searching for the Higgs boson,
they will be looking for evidence to support the heady conception of the
universe current in physics.
According to this view, everything that you can see in the universe --
stars, planets, whole galaxies, or indeed the furniture in your room, the
clothes you wear, and you -- is made of subatomic particles called quarks.
Quarks are what you will find if you take a nucleus, pry open the protons
and electrons, and gaze inside. Anything that you can see and touch and feel
is ultimately made of quarks.
"So that seems a nice picture of the world," Robert Orr says. "But what
astronomers have found is that most of the mass of the universe doesn't
consist of this. If we look at our solar system, it seems okay. The planets
behave just as Newton thought they would. But if we look at the galaxies, we
see they behave in ways we didn't expect. We know they behave that way
because something is exerting gravity, but it's something we can't see. We
call it dark matter."
You cannot see dark matter, because it does not interact with light. Yet as
you read these lines, it is all around you in the room. It is, in Prof.
Orr's word, "imponderable. When we calculate it all up, we find that the
matter we see is only about 5 per cent of the universe. This doesn't make
sense, but it gets worse."
The extra puzzler came from the expansion of the universe. For decades,
astronomers expected that the rate at which the universe expanded, propelled
outward from the Big Bang, would decrease. But about 10 years ago they
discovered that, in fact, it was speeding up.
Science cannot account for this by adding up the forces of observed matter
and the calculations of how much dark matter there should be. There had to
be something else. They call it dark energy. In this view, the universe is 5
per cent observable matter, 25 per cent dark matter and 70 per cent dark
energy.
To probe that mystery at CERN, the Canadians have installed in the tunnel's
detection chamber a calorimeter (heat detector) composed of sheets of
copper, lead and tungsten, enclosing layers of very cold liquid argon.
Particles passing through the argon leave a footprint. Since the signatures
of particles of observable matter are identifiable, everything else could be
dark matter.
If the ratio of observable matter to dark matter conforms to suppositions,
then everything not accounted for in the mathematics of the expanding
universe should be dark energy.
"The question of dark energy, of what it is, is the big question in
cosmology," Richard Teuscher says. No one in the ATLAS team suggests that
they will solve it. But they hope to find, if not its essence, its shadow.
So all that we see is a sliver of what is -- and much of that is rushing
away from us propelled by forces no one understands. If God so loved the
world, as the gospel says, He did not seem to think He had to make it
simple.
The star that the three kings followed to Bethlehem -- where is it now?
It must be where it always was -- in the same vast storehouse that contains
the known structure of the universe, the idea of dark energy, the habits of
belief, the will to see. It must be in the roomiest domains we know, the
heart and mind of man.
Matthew Hart is a Canadian writer based in London.
Jim Virdee, Imperial College London:
"We know something is going to happen. We may find
particles we've never seen before. Maybe nature has sorted things out in a
way we haven't thought of."
John Polkinghorne, particle
physicist turned theologian, Cambridge:
"There is more going on than simple reductive
physical science will be able to define. And that means there is scope for
the operation of higher causal principles."
David Wilkinson, Lecturer in Theology
and Science, Durham University:
"Physicists don't say, 'Let me prove God.' Only that
there are bigger questions than physics can answer, questions raised by
physics itself, such as 'why is everything here?' "
Canadian physicist Richard Teuscher:
"The question of dark energy, of what it is, is the
big question in cosmology."
Robert Orr, University of Toronto:
"When we calculate it all up, we find that the matter
we see is only about 5 per cent of the universe."
Print E-mail Share
Letter to The Editor of Globe and
Mail |