A massive change of gear gives a big test for science

Two years ago, few had heard of the Large Hadron Collider at CERN – the giant atom smasher designed to unveil the smallest and most secret particles of physics and the universe.

But as it is prepared for a well-earned maintenance break this December, the world's biggest machine – which has Yorkshire science and technology at its heart – has firmly entered the public consciousness, and not without some degree of trepidation.

Sheffield-based scientists overviewing key operations at the heart of the gigantic atom smasher at CERN near Geneva are now already looking forward to the next stages of the world's largest experiment, which will eventually see the already colossal machine turn into a Super Large Hadron Collider.

Since the machine's restart after its much publicised breakdown nine days after it was switched on in 2008, world record energies – of the type almost unimaginable to the man on the street – have been achieved at CERN.

And while the elusive Higgs Boson – one of the key particles that underpins what physicists call the Standard Model of Physics – has yet to be identified, a plethora of data both confirming and revealing new ideas to scientists has been generated.

Now, and over the next decade, Yorkshire know-how is spearheading a new type of space race – one which is looking to the very small rather than the very large.

Scientists across the world reckon Nobel Prizes could be awarded to its lucky victors.

The hope is that the LHC's record-breaking smash-ups could uncover evidence of dark matter, discover new forces in physics, unveil new dimensions, and even find the Higgs Boson.

"It's a bit like a brand new, very high performance car," says Professor Dan Tovey, who along with his team from the University of Sheffield, have played a major role in designing and building ATLAS, one of the colider's huge particle detectors. "When it is first commissioned we know what it is capable of, but of course nobody runs it up to its top speed straight away. For that reason, tests and performance improvements have been run in stages, culminating in March's record collision energy; the LHC has effectively been changing to higher and higher gears.

"Apart from the high energy collisions which are now taking place, we of course have to be able to detect what is happening during these huge impacts, and this is where ATLAS comes in.

"If all the data from ATLAS were to be recorded, it would fill 100,000 CDs per second. We are only recording a fraction of the data, the equivalent to 27 CDs per minute. This experiment is the culmination of half a lifetime of effort and the excitement is unlike anything we have experienced as scientists."

The possible questions which could be answered by the experiment include such weighty problems as the origin of mass and whether space as we know it actually has extra dimensions.

Prof Tovey adds: "Over the next eight years work will continue to refine the colider to improve the chance of finding rare particles.It is like looking for a needle in a haystack, but the more data we can collect, the better the chance we have of finding the Higgs Boson."

The Higgs Boson – sometimes called the God particle – has become emblematic of the quest for CERN's search for the very building blocks of everything. So much so that the scientific community reckons Nobel Prizes will be up for grabs by the finders of the yet still hypothetical particle. And scientists at CERN want to be the first.

"The difficulty lies in distinguishing it from the other, more mundane, particles which are also produced at the LHC," says Prof Tovey. "To do this takes a lot of data. To use the haystack analogy again, if only one haystack among many contains a needle, the more haystacks you examine the more likely you are to find the needle."

A special computing grid has even been established to number crunch the colossal amounts of data the atom collisions generate.The LHC is not alone in the search for the very small. The Tevatron collider at Fermilab in the US, the second largest collider in the world, is also on the hunt, but much to the delight of those at CERN it is increasingly being made to look pedestrian compared to the LHC.

Nevertheless, it does have the advantage of having been running consistently for 10 years and so it has already been able to record a very large amount of data, albeit with lower energy collisions.

The race to find new particles such as the Higgs Boson is therefore increasingly resembling a race between a tortoise and a hare. Scientists working on the LHC hope that this time the hare will win.

In a realm of superlatives, talk is even circulating of what could follow the LHC and its proposed Super upgrade – namely the Very Large Hadron Collider which all things being equal should come to fruition in eight years time. But as of yet, such a scientific leviathan remains in the imaginations of the CERN boffins and others worldwide.

What is certain is that in the coming years, the search for the building blocks of existence will be ramped up markedly. Much – including a multi-million pound contribution from the UK to CERN – is at stake.

Will a Yorkshireman discover God's particle? Only time will tell.

Prof Frank Close, of Exeter College, Oxford, one of the world's leading authorities and respected authors on particle physics says: "Twenty years ago many of us thought the LHC would be impossible – it was so far ahead of known technology that there were any number of show-stoppers that could have derailed the enterprise.

"The fact that it exists, and works, is itself a testimony to human genius – and perspiration. Does the Higgs Boson exist? Are weird phenomena that no-one has yet thought of, about to be discovered? Only Nature knows. Soon, humans will too."

For the moment, in the search for the secrets of the universe, with pounds, pride and prizes at stake, it seems heaven can't wait.

INSIDE THE MACHINE THAT STRADDLES TWO NATIONS

It might have been built to study the tiniest of particles, but the LHC is the largest and most complex machine ever to have been made.

Lying 100 metres below ground, its 27-mile circumference straddles both French and Swiss territory.

When the two beams of protons collide, they generate temperatures more than 100,000 times hotter than the sun.

The machine also counts as the world's largest fridge, with all the magnets cooled to –217C using more than 10,000 tons of liquid nitrogen.

It cost 4.5bn, but even vast amounts of money can't always guarantee that things go smoothly.

Just a week after it got going in September 2008, the collider came to an unexpected halt. It emerged that some of the LHC's super-cooled magnets had heated up by as much as 100C and a tonne of liquid helium had also leaked into the tunnel.

Amid many red faces, early reports suggested the likely cause of the mishap was a bird dropping a piece of baguette into the machinery. According to eye witness reports a bird had been spotted eating at one of the points where the mains electricity supply entered the collider.

Earlier this year, the machine experienced more trouble, but this time birds were in the clear.

Following a power cut, thought to have been caused by storms, the collider took three days to recover.