The Large Hadron Collider

As Poneke notes, the Large Hadron Collider is about to start up. Particle physics experiments have come a long way since Rutherford.

For those who are interested in what we hope to find I'd recommend this post from Sean Carroll which rates each possibility with a helpful (but subjective!) likelihood.

This is a very exciting time for physicists. The one piece of our basic understanding of the world (known as the Standard Model) that no one has seen is called the "Higgs boson". It's also the most improvised, number 8 wire part of the theory and it's quite possible that we don't understand the detail of this aspect of the theory.

The LHC will almost certainly observe the Higgs boson (95% in Carroll's rating), or whatever it is that in the real world does the job that the Higgs boson does in the Standard Model. Two possibilities for modifications of the Standard Model that might be required by the new experiments go by the name of "supersymmetry" (60% in Carroll's rating) and technicolor (about 5%). Either of these possibilities, or the discovery of something totally new, would hugely revitalise particle physics theory (oh and experiment, my biases are showing).

The nightmare scenario is the observation of just a Higgs boson that looks exactly like the one in the Standard Model and nothing else. That might make it really difficult to build any new colliders, and significantly demoralise those who, like string theorists, hope to one day develop a really consistent theory of universe.