First of all, I am way, way too excited for Wednesday.
Murray Gell-Mann simplified the zoo of fundamental physical particles in the 1960's by identifying their similarities in their symmetries. All 80 (or something) types were made up of three quarks. In the late 60's, the first electron micrographs of protons were taken, finding within this fundamental particle three smaller particles of the correct charges, but of indiscernible structure. These quarks, together with the electron and electron neutrino are capable of explaining everything in the actual world. Among the things that remain unexplained is why there are three families of each of the aforementioned, which are identical in every respect except that they are of three different masses. How is it possible that there are, in perceivable existence, three versions of the exact same fundamental particle which perform the exact same function and have what appears to be the exact same structure?
There is another particle, called a Higgs boson, which - should it actually exist - answers the profound question of why and how things acquire different masses, why so many distinct fundamental particles can arise from the same three quarks, why unique particle interactions occur in particular fashions, and exactly which roles those forces play in our universe.
Particles gain different masses because of the different ways in which they interact with Higgs bosons. Essentially (and I'm not going to try to tackle the actual equations because my mind is feabile and my brain is exhausted), Higgs particles are dark matter. They fill every "empty" space in the universe, and as fundamental particles stream through the universe, those that are said to acquire mass are bombarded with Higgs bosons which slow down their streamline. Those particles which do not acquire mass (photons, etc.) are not impeded by Higgs particles... hence, nothing travels faster than the speed of light :)
The Large Hadron Collider at CERN has been designed (and under construction and legal debate since 2003) to see if the Higgs boson can be revealed. The problem with the Higgs boson theory right now is that it is just mathematical theory - there is no physical observation. The idea behind the LHC is that, as it is a particle accelerator, the collision of protons accelerated within it can result in the creation of a new particle. The energy created by the collision is proportional to a mass (this is the real meaning of E=mc^2), and so a new particle with a new mass can result.
This is why tomorrow is so fucking sweet. Tomorrow... Sept. 10, 2008... and more importantly, Wednesday... the LHC will be "turned on," and the first proton beam will be circulated through the tunnel. The Tevatron particle collider in the Fermi Lab outside Chicago is almost as powerful as CERN's LHC, and may have already shown the existence of the Higgs boson, but have not produced any data, as such. The idea of the LHC is to recreate the conditions up to milli-seconds following the Big Bang, and hopefully make strong suggestions about the nature of this minor event in history.
The identification of the Higgs boson would mean remarkable things for the entire world of physics, beginning with the completion of the Standard Model of particle physics. Specifically, the Higgs boson would give a distinct variable to the differences between massive and massless particles, thus making possible concrete suggestions (as opposed to theoretical) about the nature of the relationship between the four fundamental forces (electromagnetism, gravitation, weak and strong nuclear forces).
Ergo... more redefinition and tweaked theory of the Big Bang.