Recently, I went on a visit to Cern (the European Organisation for Nuclear Research) in Geneva, site of the Large Hadron Collider (LHC). The LHC, whose much heralded opening last September ended in tears just nine days later, is due back in action this September. The LHC could transform scientists' understanding of the particles and forces from which the universe is made. Two beams of subatomic particles will be forced to collide at very high speed inside the circular accelerator, creating conditions similar to those just after the big bang.
One of the LHC's key assignments is finding the Higgs particle. The Higgs, thought to be responsible for giving other fundamental particles their mass, is the last piece in the jigsaw of the "standard model," the theoretical framework used to understand all known particles and forces. The Higgs is thought to have too much mass to be made in existing accelerators—the bigger this (still unknown) mass, the more energetic particle collisions have to be to spawn a Higgs. The mightiest accelerator until the LHC, the Tevatron at Fermilab in Illinois, lacks the necessary oomph.
The LHC's failure happened when an electrical short circuit caused a leak of the liquid helium coolant, which in turn ripped from its moorings one of the immense magnets used to accelerate particles through the 27km tunnels, blasting a hole in the ring and contaminating it with debris. The clean-up and installation of new safeguards have been going on ever since.
Engineering failure is hardly surprising in a project this complex. And, as physicist John Ellis told me, no matter how much brain power lies behind the planning, it's usually the "stupid things" that go wrong. Yet the delay wasn't entirely unwelcome—a physicist working on one of the LHC experiments admitted that they weren't quite ready for switch-on last September. He was talking about preparation for collecting data, not factors connected to the accident—but in any event, everyone seems confident that another such mishap is unlikely.
There's optimism all round, especially since communications between the scientists and management improved when the new director-general Rolf-Dieter Heuer took up his post in January. But a year's delay is a long time for researchers waiting for data. To make up, the LHC will run during the coming winter. That will hurt the budget—but at €6.6bn so far, who's counting?
Meanwhile, the Tevatron faces an uncertain future. Despite its illustrious career, the collider will soon switch off for good, having pretty much exhausted its potential. But it still has the go-ahead for 2010, and might run in 2011. Fermilab scientists hope to glean more information about the Higgs. They have already been able to estimate the particle's smallest possible mass, although it's debated how trustworthy the figure is.
But the Higgs is not the whole story. Arguably a more exciting goal of the LHC is to explore the uncharted waters beyond the standard model. In particular, a property called supersymmetry might unite the family trees of all the known particle families. Supersymmetry implies that the particles in one superfamily, called bosons (including protons), have partners in the other superfamily, called fermions (such as electrons). The LHC hopes to find these supersymmetric particles, if they exist, but an experiment at the Tevatron might just catch a glimpse of supersymmetry's influence first. That will stretch Fermilab's capability to the limit, but it would steal a big slice of the LHC's thunder.
Politicising particle acceleration
Cern scientists were caught unawares when, in May, Austria's science minister Johannes Hahn announced an intention to withdraw from the international collaboration. Austria, which has some of the most able physicists in Europe, contributes €16m to Cern, which represents 2.2 per cent of the funding provided by the 20 member states. That's just 0.5 per cent of Austria's science budget, but Hahn decided that it was too big a share.
Hahn offered no explanation. Worse, he seems to have taken the decision unilaterally, consulting neither the scientists involved nor the Austrian chancellor Werner Faymann. Hahn's conservative People's party forms a tense coalition government with the centre-left Social Democrats led by Faymann, and Hahn's decision smacked of political manoeuvring. To general jubilation, Faymann quickly stepped in to overrule him. With other new European states, such as Romania, queuing up to join Cern, Hahn was in any case out of step with the times.
Dan Brown's contribution to science
Surprisingly prominent in the corridors of Cern are posters advertising "the science behind Angels and Demons." The Dan Brown book, in which Robert Langdon foils a plot to obliterate the Vatican with a bomb made from antimatter manufactured at Cern, drew so many inquiries that the centre set up a dedicated website, which immediately became the most visited page on its domain. Now the recent movie is stirring up interest afresh. Given the shaky physics on display in the film, it must be a mixed blessing. But the PR team can be forgiven for seizing on both an educational opportunity and a diversion from the LHC's travails.
