In conversation with Nobel Laureate Jack Steinberger

Awarded the 1988 Nobel Prize for Physics for his discovery of the muon neutrino, Jack Steinberger has been part of the CERN establishment for almost 50 years. He recently celebrated his 90th birthday and can still be found in his CERN office on an almost daily basis. If you happened to have a coffee with him… this is what he would tell you: his recollections, and thoughts about the present and future of particle physics.

I’ve been at CERN for 45 years, and I’ve seen this organisation go through a lot. Experiments have grown significantly and so have the aspirations of particle physics. When I did my thesis 64 years ago, I could do it alone in just 6 months and I could get worldwide interesting results. Now, experiments at CERN are made up of hundreds, if not thousands of people, working for 20 years to get a result.

My thesis advisor was Enrico Fermi, and in 1953 – unless it was 1952, I’d done my thesis a few years before - he was asked to be the chairman of the APS. It was more of an honorary job, but one of his few obligations included giving a farewell address at the end of that year. He gave a speech about the physics of the day, and it was a time when particle-producing accelerators were just getting started. The first accelerator used to produce particles was the cyclotron at Berkley and it had just gone online in 1948; although they were much smaller then than they are now, they were the biggest experimental devices ever made at that time. And so, in his speech, Fermi imagined what the final – or rather, the biggest – accelerator would be. He drew a circle that went around the globe, representing a particle accelerator that went around the Earth. The LHC has a diameter of 9km, so it’s 1000x smaller than the accelerator that Fermi imagined.

That was the dream over 50 years ago, but as for the future of particle physics – especially after the LHC – I do not know. It will depend on what we find out at the LHC and no one quite knows what that will be. But there is clearly a general interest in the kind of physics that we do here. A cultural interest – we want to know what the world is like and this part of the unknown that we are trying to understand here. But there’s also the fact that experiments are always getting bigger and more expensive; there is a limit as to what governments will be willing to invest.

Hopefully something interesting will come out of the LHC. What everyone is interested in, myself included, is something that gives us indications of new physics outside of the Standard Model. For me, any indication beyond this would be something absolutely beautiful. So far, everything that we have found can be interpreted within the Standard Model.

But now I spend most of my time trying to follow what is going on in astrophysics. With the discovery of the inhomogeneities of the cosmic microwave background in 1992, and their precise measurement since then, astrophysics and cosmology have seen a beautiful advance in the last two decades, but I am afraid that further progress, learning about dark matter and dark energy is challenging. I hope that the LHC will help us to learn what dark matter is.

Interview by Katarina Anthony for the CERN Bulletin.