Tuesday, February 13, 2007

LHC: Why does it matter to us?

The entire physics community is pretty excited these days, but it just seems that this excitement is only prevalent in that community. I suppose that's to be expected -- after all, why does it matter to non-physicists?

What is this excitement all about, anyways? I speak of the near-completed Large Hadron Collider (LHC) near Geneva, Switzerland. It is a monumental addition to the existing CERN particle collider that has served as the forefront of particle physics research for a good half century now. Places like CERN have produced an amazing amount of good experimental research that have propelled the frontier of physics ever forward. Experimental verification of quantum theory, the electroweak theory, and most impressively the Standard Model have all come out of particle colliders.




I suppose the question could be extended to all this: why do huge, multibillion dollar projects that do nothing but smash infinitesimally small particles matter to anybody? It seems like a very, very large and expensive toy for a physicist, doesn't it?

The core reason is because we have generally reached the upper limit with our current particle accelerators -- they can only accelerate particles to a certain energy level and the results we get cannot answer the burning questions of physics anymore. It seems like a paradox, that it takes higher and higher energy levels to probe deeper and deeper into the world of the small -- so small, in fact, that quantum mechanics is an inadequate description of this world.

The most intriguing area of physics, in my opinion (some physicists will disagree), is string theory. It is also the most tenuous area of physics -- because it is so theoretical (and in the words of my friend, Benedikt Riedel: so full of bullshit) and mathematical we do not know if any of it is "true" (in the sense of experimental evidence). The fact is, there is not a single piece of evidence supporting string theory -- and physicists have been working on modern string theory for the past twenty years. But what has been keeping them going is its sheer mathematical elegance. Can something be so elegant that it has to be true? Certainly, many physicists think so.

But the LHC is the reason why many physicists are starting to place bets now -- because they're hoping with the awesome level of energy that is attainable with this machine, it can start to shed some light on the most fundamental questions of physics today. For example, physicists are eagerly awaiting the experiment to test the existence of the fabled Higgs Boson. Of all the particles predicted by the Standard Model, the Higgs Boson is the only one that remains unidentified by experiments. The Standard Model has proved its success and versatility with everything else so far. The Higgs Boson is, simply, the particle hypothesized to give everything a property of mass (for everything that has mass, of course). That's pretty big stuff. Can you imagine that without this particle, nothing would have mass?

Hopefully, too, some aspects of string theory can be tested. That would re-instill a much needed sense of purpose, direction, and excitement in the field of high energy physics. And some deep, fundamental questions about the fabric of reality and its constituency could be answered.

1 comment:

atombombforpeace said...

Hmm, from the links I can see a lot on the workings and how they intend to accelerate the ions, but how exactly are they getting results? The wikipedia article suggests what types of research they could answer, but what type of recording devices are there, and how much is extrapolation, as opposed to fact?