See the "My Personal Theory" section of the post from Ron Maimon at physics.SE:
http://physics.stackexchange.com/questions/3799/why-is-cold-fusion-considered-bogus/13734 Ron had a long post here for a while now, but very recently he updated it to include new material in his explanation section. The basic gist (of the section, not the update): In order to have fusion under chemical conditions, you have to find a way to bridge the gap in energy between the chemical realm, in eVs, and the nuclear realm, in MeVs. Conveniently, the K shell of the Pd atom has 20KeV of ionization energy. If a K shell electron is kicked out (by a photon, for example), the resulting hole will potentially attract a proton or deuteron nearby, transferring 20KeV to the incoming particle. If there are two such holes, and two deuterons are brought in, they will meet with sufficient energy to fuse. The resulting alpha particle will then race through the neighborhood of the fusion event, ionizing Pd atoms as it goes and giving rise to new holes in turn. Ron sees problems with this explanation, but it is interesting nonetheless. He also has an explanation for transmutations which is worth looking at. Fascinatingly, Kirk Shanahan is one of the commenters on the post. It's a small world. Eric
