On Tuesday afternoon, a seminar will be delivered at the Cern particle physics laboratory outside Geneva. An update on the search for the so‑called "God particle", the Higgs boson, this is perhaps the most eagerly awaited scientific presentation of the century to date.
Here at Cern we haven't been getting much sleep lately. Having worked on the Atlas experiment – one of two general-purpose particle detectors at the Large Hadron Collider (LHC) – for about 10 years now, I'm anxiously waiting to find out whether CMS (our counterparts on the other side of the collider) agree with our findings, and wondering what this might mean for my field of work. This seminar could change physics forever. On the other hand, it might not.
Science is often presented in neat little packages. Gravity does this, electricity does that, DNA does the other. But this is not how new science happens. Rather, these "neat little packages" emerge from a grungy mess of uncertainty that would make any sausage butcher proud.
The LHC at Cern is a 27km tunnel full of superconducting magnets, which has been colliding protons head-on at huge energies. Thanks to this machine, we will know quite soon which option – Higgs boson, or not – is realised in nature. If you are curious about the universe we live in, the prospect is pretty tasty either way.
The Higgs boson is a long-searched-for prediction of the "standard model" of particle physics. Should it exist, it is responsible for the mass of the fundamental particles we are all made of, such as electrons and quarks. Its discovery would be a stunning vindication that our aesthetics and mathematics are genuinely connected with how the universe really operates. If it doesn't exist, then in a sense it's back to the drawing board: it would mean our understanding of nature has failed at the energies accessible at the LHC. We would have to learn some new tricks.
What a messy, and fun, year this has proved for particle physics. Many physicists, though, are nervous about the huge public interest in the subject at present – and the very public question marks hanging over our work as a result. What if the Higgs boson does not exist? And what of that other Cern-based experiment which gained notoriety recently, when beams of neutrino particles appeared to have travelled faster than the speed of light, having been fired under the Alps to the Gran Sasso laboratory east of Rome. If true – and many still doubt the results – this finding would, to say the least, present a bit of a problem for Einstein's relativity theory; a theory that, though very weird at first sight, lies behind much of modern technology.
But the neutrino experiment might yet be proved wrong. The Higgs boson particle might not exist. We may look silly. All three of those statements are true, and will remain true whatever results are announced on Tuesday. For scientific knowledge is about probabilities; it is provisional.
I believe there is a huge opportunity in all this doubt and debate. It is worth being wrong in public sometimes. We should all know that science is a betting system, not a belief system. Near-certainty arises from a morass of uncertainty, it does not drop from heaven gift-wrapped. You never know, 100%. But you would be a fool to bet against a well-established scientific fact, be it gravity or the existence of quarks.
With Tuesday's new results, the odds will shift either in favour of or against the existence of the Higgs boson. The Higgs (for or against) might make it to the 5% or 10% level: 5% chances turn up quite often in the real world. Eventually, the odds for or against its existence may be many millions to one. At that point we'll pretty much stop discussing that, and move on. Apples fall down, the sun comes back in the morning, the proton is made of quarks. These are all pretty certain at the billions to one level.
What is beyond question even now is the huge economic benefit of particle physics. The technologies developed at Cern have already changed our lives. And, while neutrinos and the Higgs boson may seem distant from everyday life right now, I would bet that we will use them to make money and improve our lives in the long run. After all, relativity and quantum mechanics are pretty esoteric, but they underlie practically all modern technology.
But perhaps one of the biggest benefits of the current excitement will be this: watching the twists and turns of the neutrinos or the Higgs might, just might, help us as a society to become better equipped to make sense of other scientific issues, which are more politically and economically charged. MMR, stem cell research, climate change, GM foods: which way would you bet?
Often the mix at the emerging edge of science is liberally adulterated with political and economic bias, and simple hubris. Even in particle physics there are massive egos and perhaps slightly less massive careers at stake – some of which got their mass from the Higgs. This is because science is, in fact, a human activity. It's just special because it is the best way we've found of getting the right answers. Probably.
