December 16, 2011 7:52 pm

Rejoice in the mysteries of our universe

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Particle physics spreads its appeal, writes Clive Cookson

Big physics has burst back into the news with a bang. This week’s headlines highlighted the hunt for the Higgs boson, labelled indelibly as the “God particle”. Earlier, the discovery of neutrinos apparently travelling faster than light grabbed the imagination of the media and public alike.

The stories herald a cornucopia of revelations about the nature of our universe in the coming months and years, following a relatively quiet decade for fundamental physics and cosmology. We should be in no doubt that these are likely to transform physics as much as the discoveries of the 1990s, when astronomers first mapped the background radiation from the Big Bang 13.7bn years ago and found that an unknown force, dark energy, was blowing the universe apart.

The forces and particles that shape the universe probably lie beyond human comprehension; we have not evolved to grasp quantum physics at its deepest level. Yet the drive to make some sense of them is mankind’s most inspiring intellectual endeavour, ahead even of research into the human brain. The astonished reaction of colleagues and friends this week leaves me happily convinced that for all its rarefied reputation, even in this time of acute economic uncertainty (or maybe partly because of it) particle physics has at last spread its appeal far beyond the scientific community.

And quite right too. This has been a remarkable year. The big difference between the two announcements of the year is that September’s revelation of neutrinos breaking what for more than a century has been seen as the cosmic speed limit came out of the blue. If confirmed by further observations next year – a big if – the discovery will overturn the whole framework of post-Einstein physics.

In contrast to these revolutionary implications, the discovery of the Higgs boson has been discussed since the 1960s. To the extent that the Higgs gives shape and substance to the universe it may justify the “God particle” title, which was bestowed by the American physicist Leon Lederman in 1993. Many physicists dislike both the religious connotations and the hype implicit in a God particle but they recognise the public relations value of the title.

In truth, discovering the Higgs is not a eureka moment but a long and painstaking analysis of the subatomic debris from billions of proton collisions. The “tantalising hints” of a Higgs particle about 130 times heavier than the proton, revealed this week, did not reach the statistical significance required to claim a discovery – and might yet melt away in the face of more data.

Next year, promised Rolf Heuer, Cern’s director-general, the Large Hadron Collider will provide enough new data to answer his “Shakespeare question for the Higgs: to be or not to be?” If Higgs exists, physicists will cheer with relief and move on to construct theories that go beyond the Standard Model. The shock would come if the Higgs turned out not to exist. Then Cern would face a public relations problem, and physicists would have to start looking again for an explanation of how God created mass.

The position is utterly reversed in the other big physics story, which was truly astonishing. Researchers on an experiment called Opera this autumn published evidence that neutrinos – subatomic particles with extremely low mass that pervade the universe but hardly interact with ordinary matter – had travelled from Cern to an underground lab at Gran Sasso 730km away in central Italy slightly faster than light.

“I’ll eat my hat if that turns out to be true,” Pier Oddone, head of Fermilab, the leading US particle physics centre outside Chicago, told the Financial Times. Another well-known physicist, Jim Al-Khalili of the University of Surrey, said he would eat his boxer shorts on live television. Their scepticism reflects mainstream scientific opinion.

The Opera team published a follow-up study last month, eliminating one possible source of error in the measurement of the neutrinos’ speed. However, the superluminal claim should be settled one way or another by more observations next year – though they will need to be made independently at a different detector. The US Minos experiment, which shoots neutrinos a similar distance from Fermilab to an underground detector in Minnesota, is ready for action.

If the Opera result is confirmed and the professors have to eat their words (and clothes), physicists will enjoy an intellectual feast as they try to explain how neutrinos can break the rules established a century ago in Einstein’s theory of relativity. Already there is talk about the particles using extra dimensions to take short-cuts through space-time.

So 2012 is shaping up to be a defining year for physics. The most shattering outcome would be the confirmation of superluminal neutrinos and no Higgs. The most likely is that Higgs is detected but the neutrinos’ speed is deemed to be below that of light.

But to be clear, and to my delight, there is much more physics to come. Next year could also see the first evidence of phenomena beyond the Standard Model. For instance a theory called supersymmetry introduces a new panoply of particles – superparticles or sparticles – some of which may be produced soon at the Large Hadron Collider.

Then there is the possible discovery of the identity of the “dark matter” that makes up about a quarter of the universe, and of the reason why matter rather than anti-matter dominates the universe. And what of the chance that we might glimpse into those hypothetical extra dimensions of space?

Settle back. The secrets of the universe could be quite a distraction next year from our woes.

The writer is the FT’s science editor

Clive Cookson

AudioClive Cookson talks neutrinos with Pier Oddone

FT science editor Clive Cookson talks neutrinos with Pier Oddone, director of leading US particle physics centre Fermilab

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