Hello all, I was recently talking about the Seebeck effect with one of my colleagues, and we've run into a bit of a puzzle. Why are *dissimilar* metals required to produce it? All of the various sources I've consulted state very clearly there must be two different metals (or I suppose you could cheat a bit and use a semiconductor, like Pasco does in its little toys), but none of the sources explained why! I would have thought that the electron diffusion from the hot to the cold side of each part would create the greatest potential difference if the same metal was used for each "leg." Clearly there must be something wrong with my thinking . . . Enlightenment received with gratitude!