Visiting CERN

Last week, I was visiting the CERN site near Geneva, Switzerland for work. I was attending a workshop on Quattor, a powerful tool for automating the system configuration of large numbers of systems. Learning Quattor is a necessity, because the UGent HPC team I'm part of relies on it for managing roughly half a thousand systems today, and will be relying on it for many more in the upcoming years.

The CERN site lives and breathes science, you could just feel it when strolling between the various buildings. There was a very professional feel to it all, with fairly strict access control to the site, very well occupied meeting rooms and monitoring screens with live updates on the Large Hadron Collider (LHC) operation status in pretty much every building. Having lunch in one of the large on-site restaurants only added to the feeling that working at CERN must be a dream come true for a geek/scientist.

Unfortunately, we had little time to visit many of the really interesting things to see there. We had a quick glance at the massive Tier 0 data center, took the visitors exhibition tour in the giant wooden globe across the street and walked through the "Microcosm" exhibition, where we saw a rather old but very interesting movie clip on the discovery of the W boson back in the 80s.

A guy taking part in the Quattor workshop was able to explain me the basic goal of the LHC and its detectors. The whole deal is to find the Higgs boson, also called the God particle. The way I understood it, is that the Higgs boson is a really heavy particle that can not exist without huge amounts of energy being available to sustain its existence. It is roughly known how heavy this particle should be (if it exists), and thus also how much energy is needed to keep it alive, if you will. The LHC will be able to deliver this required energy, and thus should allow to observe the Higgs boson.

Here's the interesting part: if it's not being observed, not even when the LHC reaches its maximum capacity in the next couple of years, then the theoretical model of physics that has been widely accepted during the last couple of decades is wrong. That would mean that most of the recent research in physics will have to been questioned all over again. Just imagine the impact that would have.

However, there's a catch. Observing the particle is not as easy as it sounds. The huge detectors that were built for LHC experiments like ATLAS and CMS generate huge amounts of data. I was told the noise-to-signal ratio is a couple of billion to one, meaning that a huge number of observations needs to be done to make one potentially interesting observation. Even after filtering out the trivially uninteresting observations, the amount of data that needs to be processed is enormous. Hence the need for a huge data center like the Tier 0 on the CERN site, which is assisted by eleven Tier 1's and hundreds of Tier 2's all over the world.

Even though we didn't get to see the LHC up close, visiting CERN has been a very interesting experience. I hope I'll be able to return in the near future, and learn more about it all while scientific history is being made.