There's been a fair bit of LHC buzz in the media and on the blogs. Everyone mentions the Higgs mechanism, of course, which no one particularly seems to understand -- not surprising, because it's a fairly subtle business. The most frequent misconception is that the Higgs mechanism gives gravitational mass to other elementary particles; this is incorrect, because the standard model doesn't have gravity in it.
There are two kinds of mass in physics, inertial and gravitational. Inertial mass is the m that appears in Newton's law F = ma (the ratio of force applied to acceleration achieved) or in Einstein's equation E = mc^2. It's basically a measure of how hard you've got to push something to get it to move, and has nothing to do with gravity. Gravitational mass is a measure of how strongly objects attract each other. Empirically these masses are the same; this is the content of Newton's law of gravity. The Higgs mechanism explains why particles have inertial mass -- it's because (very crudely) they have to push against the Higgs field to move. (The Higgs boson is a ripple of the Higgs field, just as a photon is a ripple of the electromagnetic field.) This story, for obvious reasons, doesn't go very far towards explaining gravity.
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