Absolutely right! What may have been unclear' date=' however, was that the problem relates not to fusion, but to the energy output of a typical gerbil/hamster. Gerbils are warm, and the amount of heat energy a hamster outputs per unit mass is so much greater than that of a star. So, if you managed to place an equivalent mass of gerbils where the sun is, the energy absorbed by the Earth would be many times greater than it currently is, leading to its incineration. See Professor Estimates Power of Gerbil Sun This is actually the same professor that posed this very problem to me!