I’ve just got back from a particle Physics Masterclass at UCL. Here’s a brief outline of what we did and what I thought.
After a number of technical difficulties involving the projector, the morning programme began. Interestingly, two of the lecturers were using Macs and the lecturer on distributed computing was running Linux with what looked like a GNOME desktop. Sadly for Linux supporters like me, it subsequently crashed apparently owing to the wifi (so cafe wireless at school isn’t that bad after all), after which he either did a really fast XP install or dual booted to XP.
1100 The LHC, ATLAS @ CERN
Dr Mario Campanelli, a researcher at CERN as I understand from his intro, gave us a brief talk on the LHC and the detectors. We got a brief description of the various different particles and a run-down on how precisely aligned the LHC’s parts had to be (0.1mm), leading to its being underground; why singularities produced in it weren’t going to swallow the earth and KILL US ALL (black holes would quickly evaporate in a puff of radiation), and besides cosmic rays hitting the Earth’s atmosphere create such singularities all the time – we’d be long gone by now if those were the Earth-swallowing type of black hole; the setup of the tubes; and a bit on how the detectors work. There was a lot specifically about CERN that I didn’t know before and that hadn’t been mentioned so I think we all found this particularly interesting.
He also said as a sidenote that apparently CERN would have closed over winter anyway owing to electricity costs, so the schedule wasn’t as badly set back by the ‘minor’ ‘meltdown’ (i.e. like 27 Kelvin) as the media make it out to be. Or maybe that’s his CERN researcher pride speaking :P
1200 Search for neutrinos in Antarctica
We were then told about the tremendous difficulties faced by scientists attempting to find neutrinos. When neutrinos interact with matter they form a cone of Čerenkov radiation consisting of blue light and radio waves projected in the shape of a cone caused (as I understand) by charged particles moving faster than the speed of light in the given medium. The research brought the scientists to the icy region of Antarctica, attempting to detect radio transmissions caused by neutrinos interacting with ice which carries radio waves well. The search went from water to ice to salt as media for neutrinos to interact with, and as yet neutrinos have never been detected except from two occasions: our sun and a supernova in 1987 (or thereabouts).
1230 Distributed Computing
This was more or less about how to process the 5 PB of data emerging from the LHC while in operation. The talk touched on supercomputers, showing us pics of CRAY supercomputers from ye olden dayes and more modern cloud computing centres. The capacity of distributed computing is enormous, as demonstrated by projects such as SETI@HOME and Folding@HOME.
This consisted firstly of looking at simulated data from realistic particle collider experiments. We used Atlantis (software) and data from ATLAS (i.e. looking at particle traces and detector readings and unintelligible graphs of logs of angles against logs of other angles in some crazy units against GeV) and learnt to recognise different types of W and Z particle decays. I personally thought it was quite exciting and certainly eye-opening to be using the same software as researchers at CERN are using to analyse their data. However, realistic as the graphs and charts seemed and authentic-looking as they were, we successfully identified a Higgs Boson trace which the lecturers did not seem at all surprised about. Realistic indeed…
The day concluded with a video conference with some research labs in the US. As with all video conferences, the quality left something to be desired, but it was interesting if a little disheartening to watch the other side rip apart our conclusions from data and ridicule us as inefficient British people! In the end we ended up discussing in some depth differences in education systems between the US and the UK (apparently they start at 7:30 and finish at 2pm but were envious of our almost 2hr lunch breaks) before the sound quality totally disintegrated and nothing was left but an IRC channel!
Overall, I certainly got something out of the day. Although we didn’t really discover all that much new in terms of the theory behind particle Physics thanks to fairly thorough AS teaching, there was a lot I learnt about the practical side of particle colliders and detectors. More importantly, lunch was quite sublime (surprisingly so for pub food).