> Aren't you referring to fission? It seems to me that fusion might actually
> scale down. After all...the minimium ingredients are two hydrogen atoms.
yup. my brain was out fission when i wrote the original post. after thinking about it, i realized we are over-restricting our view with the traditional fission chain reaction scenario, the one that wont scale down. fusion maybe, if you can figure out a way to get two hydrogen nucleii to contact on a nano scale, but consider: another possibility might be to use a small radioactive sample without chain reacting anything: just by somehow capturing the high energy electrons that come off the decaying nucleii, or perhaps the alpha particles. either way, we neednt think only in terms of the big nuclear reactions that we are so familiar with way up here on the meter scale. spike