Oh, but the lack of neutron output was the most interesting part! If there had been neutrons, people would have assumed there was an obscure sort of inertial co

Oh, but the lack of neutron output was the most interesting part! If there had been neutrons, people would have assumed there was an obscure sort of inertial confinement fusion going on at some particular kind of defect in the crystal structure, perhaps a microscopic Farnsworth Fusor. Such an effect would be intriguing if it existed, but not very fundamental and probably not that useful. Cold Fusion was important because it raised the possibility of a previously unknown mass/energy conversion mechanism, or at least a manifestation of a poorly understood one like neutrino emission or absorption. Neutrinos are a good lesson in how much we actually understand the world. The neutrino flux from the sun is thought to be 10^12 particles per square meter per second, yet its mass is "Unknown, probably nonzero" [Wikipedia]. They don't seem to interact with ordinary matter much, but we can't rule out them interacting strongly with particular molecular structures in Palladium-Deuterium alloys. Nor can we rule out the presence of particles that interact even more weakly than neutrinos. The 1995 Nobel was awarded for finding evidence of neutrinos that are now thought to have been antineutrinos. Particle physics is not a solved problem.