Here I am at CERN, for the first time in more than three months. When I was here this summer, I stayed for five weeks and had my family along with me. Now I’m just here for a short stay and rooming in the hostel again. But in some ways, it feels like I never left. (Except for the jet lag, of course.) The exciting times continue on the LHC experiments. We are under two weeks from the end of this year’s proton run, and we are eager to gather every last bit of data we can before the heavy-ion run and then a technical stop that won’t end until sometime in March. The dataset that we will end with will be more than twice as big as that which we analyzed for results that went to conferences this summer, so it will be very interesting to see what emerges with the additional data.
You might not have heard, but since the last time I posted, Apple co-founder and CEO Steve Jobs died. Obviously Jobs had a huge impact on how we live in our technological world. In the days after his death, I read articles discussing his influence on computing, design, music, publishing, politics, and so forth. Eager to jump onto the bandwagon, I decided to take a pilgrimage to the CERN visitor center at the Globe, located across the street from the Meyrin site. There, you can find this computer in a display area:

A NeXT computer, from 1990.
The ratty sticker on the front implores passers-by not to shut down the computer. The computer is a NeXT, a product of the company that Jobs founded after he was forced out of Apple in the 1980’s. This happens to be the computer that belonged to Tim Berners-Lee, the first developer of what we now know as the World Wide Web, and it hosted the first Web server. (Do not shut down, indeed! Someone on the other side of the world might be using that computer.)
It’s true, we trot this one out a lot in particle physics, but the Web was invented by particle physicists to be used as an information and document sharing system, and it ended up changing the world. Particle physics has driven many developments in computer science over the years, as we’ve long had large datasets and computationally-intensive problems. These days, I feel like I see a lot of back and forth between particle physics and the computing world. Because of the scale of the data volume that we serve and the number of users who want to access it, and because we’re trying to do it on the relatively cheap, we’ve moved to a model of distributed computing that is realized in the Worldwide LHC Computing Grid. Grid computing, which allows straightforward access to computing resources owned by others that aren’t being used at the moment, has been adopted across sciences that do large-scale computing, and cloud computing is an offshoot of this development.
At the same time, we are definitely making use of computing technologies that have been developed in the commercial world. My favorite example of this is Hadoop. It’s a very powerful set of tools, and many US LHC computing sites are using its disk-management system, which is also used by Web sites like Facebook. It has good scaling properties and is easy to maintain, making life easier for site operators. We’re always on the lookout for new ideas that we can bring in from the computing world that will make it easier for physicists to make the most out of the LHC data.
Thanks to all of these tools, someone — perhaps very soon — will be making a plot that could show evidence for new physical phenomena. It wouldn’t be possible without the computing systems that I just described. Will this plot be viewed for the first time on the screen of an Apple product? Will that very screen end up in a display at the Globe? We’ll see.