QCDOC, a £7m supercomputer at Edinburgh University, has been doing a lot of
thinking lately. This is understandable: it was asked a very tricky
question. The question, with the physics-speak stripped out, was: “How come
there’s something rather than nothing?” Last week QCDOC came up with an
answer. Sort of.
In theory, you see, it is possible to prove that neither you nor me, nor,
indeed, anything else, should exist. Stuff should be exactly balanced by
antistuff (matter and antimatter are the correct but now rather jaded terms)
and therefore there should be nothing. But in fact there seems to be a
slight preponderance of stuff and so we get galaxies, planets, Condoleezza
Rice and halibut.
This is called, alarmingly, the CP (charge conjugation/ parity) violation.
It’s a violation because everything should be symmetrical, including the
amounts of stuff and antistuff. But Condoleezza and halibut violate symmetry
because, by existing, they prove there’s more stuff.
QCDOC – it’s short for quantum chromodynamics on a chip – didn’t put it that
way, and the way it did put it wasn’t entirely satisfactory. But it didn’t,
as some reports have suggested, collapse. In fact it’s still running. And
what it did find was just the beginning of what could, within a year or two,
become one of the great revolutions in scientific thought.
What the computer had been asked to do was test the standard model. This is a
theory unique in scientific history in that it manages to be both
fantastically right and unbelievably wrong. The standard model deals with
the interactions between tiny particles such as quarks and gluons. These are
what you find inside an atom, and their behaviour is distinctly odd. In fact
it’s so odd that scientists have had to resort to an entirely novel
vocabulary to describe what these things do. They use words such as
“strangeness” and “charm”.
We’ve discovered lots of these particles, but there may be lots more. The
miracle is that we have managed to make any sense at all of this tiny,
teeming world. The standard model is, in short, a miracle, a system that
predicts the behaviour of forces and particles with incredible accuracy. It
has been around for 30 years and it has withstood every attempt to knock it
down. It also withstood the mighty mind of QCDOC.
The computer tested the standard model for what it says about the CP
violation, the fact that there is more stuff than antistuff. This is a very
complex calculation that was, in effect, waiting for a good enough computer
to come along. Enter QCDOC. In fact it’s not alone. There’s a matching
supercomputer at Columbia University in New York working on this, as well as
scientists in Japan.
The standard model survived the scrutiny by showing that, under most
circumstances, it would predict the CP violation. But unfortunately it
remains unbelievably wrong.
For a start, though it showed how there could be more stuff than antistuff,
the difference wasn’t enough to explain halibut etc. Furthermore, the
standard model has a glaring omission. It doesn’t include the most elusive
force of all, gravity. And, finally, it is known that the standard model
will fail completely at very high energy levels. When we get to temperatures
close to those at the Big Bang, with which the universe began, stuff behaves
even more weirdly than it does now.
The standard model is a triumph of human thought, a masterpiece. Professor
Richard Kenway, who led the QCDOC team, implored me to tell you just how
amazing it is. Thanks to the standard model, the human mind has grasped the
behaviour of the unimaginably small entities of which the universe consists.
But, like so much else in modern physics, it doesn’t quite make sense. A
hundred years ago, for example, Einstein came up with relativity, which
deals with the behaviour of very large objects, and Max Planck came up with
the basis of quantum theory, which deals with the very small. Both are
brilliant and comprehensively tested – in terms of technological fallout,
quantum theory is the most effective scientific principle ever discovered.
Unfortunately these great theories contradict each other. Physicists since
then have been struggling with increasing desperation to make them work
together.
If they ever succeed, they will have what is known as a theory of everything,
a set of equations that will explain the entire history of stuff.
Many have been confident enough to say they are close to the theory of
everything. In 1989 Stephen Hawking promised that we should soon “know the
mind of God”. He sold millions of books on the back of it. Tomorrow Hawking
starts a series on Channel 4 about all this. Physics, when it gets this
fundamental, is very popular.
But the theory of everything still evades us. The problem is that, in spite of
the success of the standard model, we still don’t really know how stuff
works – nor, indeed, what it is – at the most basic level. The dominant idea
in physics, string theory, is in deep trouble.
Based on the notion that all matter is formed of tiny vibrating strings, it
has produced some beautiful mathematics, some wildly exciting pictures of
the cosmos but no testable predictions. As a result, the physicist Lee
Smolin described string theory as “a beautiful picture on the jacket of a
book you can never open”.
With string theory in disarray, the standard model still standing but
incomplete and relativity and quantum theory still warring in the equations,
you might think physics was stalled. You’d be right. But in physics, as in
life, if you throw enough money at a problem, you may just crack it. And
that’s what we’ve done.
The Large Hadron Collider near Geneva cost about £4 billion and is due to
start work this year. It is a giant ring-shaped tunnel around which beams of
protons will race and smash into things. Ten times more energy will be
unleashed than in any previous collider. Imagine two airliners crashing in
the space of an atom. This is what it was like milliseconds after the Big
Bang.
“We don’t know what we will find!” Kenway says with uncontained excitement.
What they hope they’ll find will make a retired Edinburgh professor who still
hangs around the physics department very happy. Peter Higgs predicted the
existence of a particle that became known as the Higgs boson. It’s never
been seen but it should exist, according to the standard model. The collider
should find it and make Higgs very famous indeed. He is 80 in May 2009,
probably about the time the collider will be producing its first results.
The Higgs boson would reinforce the standard model. But the problems with the
theory will remain. The hope is that the collider will reveal entirely new
and unexpected phenomena, signposts pointing to answers to the huge
outstanding questions of contemporary physics. Kenway thinks it will. He
believes physics is on the verge of the biggest revolution since Einstein
and Planck, possibly since Galileo and Newton. Physics is about to become
the sexy science again. For the past 50 years it’s been eclipsed by biology.
It may not happen. The collider could cause a “vacuum metastability disaster”,
an annoying outcome that would destroy the entire universe, halibut and all.
This is regarded as unlikely – “impossible”, says Kenway.
And the revolution might not happen at once. The collider is likely to throw
out so much information that it will be decades before it is deciphered. New
supercomputers will have to be constructed to crunch the numbers – but, in
the end, we may have . . . what, exactly?
Well, it won’t be a dumb book telling us God doesn’t exist; it won’t be
evidence that the only wisdom is science; it won’t, as one Nobel
prizewinning physicist once claimed, stop us reading our horoscopes. And it
won’t, in the near future, produce astonishing new technologies, though it
may well show that, for example, a time machine or rapid interstellar travel
is theoretically possible.
But it will be something like a great work of art, a vision of truth; not the
truth, but a version or image of it. Kenway – and, of course, the usually
rather reserved QCDOC – has every right to be excited.
www.bryanappleyard.com
THE MEANING OF LIFE
Martin Amis, novelist It’s an intriguing fact that humans aren’t
intelligent enough to understand the universe
Lady Mary Warnock, moral philosopher To say it’s possible or impossible
to discover the meaning of life is to say it makes sense to ask. Living
creatures are here because of some chemical reaction. Individuals are here
because their parents gave birth to them. I think we are moral beings but I
don’t think that life itself has an absolute moral purpose
Desmond Morris, anthropologist I don’t see the “meaning of life” as a
mystery at all. There are only really two interpretations: what life means
to you as an individual; or understanding life as a chemical process taking
place on a planet
David Starkey, historian There is no meaning to life other than what
the human being gives to it. That is certainly the joy and the terror of
being human
Bob Geldof, campaigner The meaning of life is life itself. It doesn’t
need to be anything more than that and afterwards it’s blissful oblivion
Cardinal Cormac Murphy-O’Connor Science is keen to explore the
question of how things exist, whereas religious faith seeks to explore the
question why. Why are human beings not satisfied by a purely mechanistic
interpretation of the world and its complex beauty? The fact [is] that life
can only find its ultimate meaning in God
Jeremy Paxman, broadcaster Can’t think what all the fuss was about.
It’s 42, isn’t it? Everyone knows that. Personally, if I had an unlimited
budget, I’d try to solve the mystery of where my missing socks have gone
