Large Hadron Collider
Over the past year or two, I have followed the sagas of the Large Hadron Collider with some interest. The countdown is on again for the second switch-on, scheduled for mid-November.
For those scratching their heads right now, the Large Hadron Collider (LHC) is the world’s largest particle accelerator. Located underground near Geneva in Switzerland, the LHC is a large, circular-shaped instrument and by large, I mean a circumference of 27km (17 miles) long. This is no test-tube experiment!
The particle accelerator works by firing two beams of sub-atomic particles (Hadrons) in opposite directions at near speed of light velocities, and monitoring the behaviour of the particles as they collide with each other. The collisions will take place in temperatures of around −271° Celsius, just a couple of notches above Absolute Zero (−273.15°C). The purpose of the LHC is to recreate the same kind of conditions that existed in the Universe just after the Big Bang. To quote their web site:
Researchers think that the Universe originated in the Big Bang (an unimaginably violent explosion) and since then the Universe has been cooling down and becoming less energetic. Very early in the cooling process the matter and forces that make up our world ‘condensed’ out of this ball of energy.
The LHC will produce tiny patches of very high energy by colliding together atomic particles that are travelling at very high speed. The more energy produced in the collisions the further back we can look towards the very high energies that existed early in the evolution of the Universe. Collisions in the LHC will have up to 7x the energy of those produced in previous machines; recreating energies and conditions that existed billionths of a second after the start of the Big Bang.
The facility, developed by CERN (same people who gave us the World Wide Web), has had its share of problems and delays during construction. It was finally scheduled for switch-on (almost a year later than planned) in September 2008. Unfortunately barely 10 days after becoming operational, around 100 of the magnets which line the collider failed and it had to be powered off again. There were additional problems in July this year with vacuum leaks in the tunnel. The scientists now believe the teething problems are ironed out and have begun cooling the Collider to operational temperatures once again for switch-on in the near future.
Last year, when the Collider was first switched on, there was a little hysteria from some quarters of the press. I suppose this quote from the LHC people didn’t help.
The results from the LHC are not completely predictable as the experiments are testing ideas that are at the frontiers of our knowledge and understanding.
This led to fantastical stories in the press about explosive anti-matter, black holes engulfing the Earth and alternate universes. (Perhaps this [slightly outdated] demotivational poster sums it up best.) My favourite loony theory however comes from a surprising source. Respected String Theory physicist, Dr. Holger Bech Neilson has speculated that the problems and delays the LHC has faced are caused by sabotage … from the future. One of the main aims of the LHC is to prove the existence of the mythical Higgs Bosun particle. According to Dr. Neilson, however, the creation of the Higgs particle may be so “abhorrent to nature” that the effect would travel back in time and stop the Collider before it could create the particle in the first place. Is your head hurting yet? Dr. Nielson goes on to say “It must be our prediction that all Higgs producing machines shall have bad luck,” He also said “Well, one could even almost say that we have a model for God.” It is their guess, he went on, “that He rather hates Higgs particles, and attempts to avoid them.”
Well dear reader, if we’ve all been crushed out of existence in a black hole by this time next week, I’d just like to say so long, and thanks for all the fish!
Further information:
Large Hadron Collider official web site
CERN’s Guide to the LHC (pdf file) – An introduction to the LHC and the physics behind the experiments







