COLD FUSION EXPLAINED

I believe the cold fusion story is at last nearing its end with an explanation provided by materials engineer Ali AbuTaha in two papers to be published in MIT's Journal of Fusion Technology, of which he kindly made preprints available to me.

To explain AbuTaha's explanation, let me start off with a high-school puzzle: what happens to the energy stored in a compressed spring when you dissolve it in acid?

When the spring is not compressed, a chemical reaction takes place between the metal and the acid, in which the heat of reaction is liberated. This heat of reaction is precisely known for each chemical reaction. (It is liberated, or positive in this "exothermic" case; in the "endothermic" case it has to be supplied to make the reaction take place.) On a molecular level this means that as the molecules rearrange themselves into new patterns or new chemi-cals, they are more agitated or more intensely vibrating than before, for heat is nothing but kinetic energy of the vibrating molecules. And "molecules rearranging themselves" means that they form new electron bonds between their atoms. The resulting energy of these electrons (radius of their orbits) is smaller than in the original molecules; that is why the heat, or difference in energy, is given off rather than being absorbed.

Now when the spring was compressed, its molecules were under stress; the bonds between its own atoms and molecules were at a higher energy level than normal. As the spring dissolved in the acid, this stress disappeared when the molecules entered the chemical reaction. But the energy associated with it cannot disap-pear; it is added to the energy of the chemical reaction. What hap-pens is that the atoms of the stressed metal are "thrown out" of the molecule at a slightly higher velocity than by the chemical reaction alone, and the resulting molecules and atoms vibrate slightly more intensely.

If you have been intimidated by all this talk about molecules and chemical reactions, the gist is this: the resulting solution is very slightly warmer when the spring dissolved in the acid was com-pressed. The additional heat is equal to the energy expended in compressing the spring. And the additional heat is neither of chemical nor of nuclear origin.

Something analogous, though somewhat different, happened to the Pons-Fleischmann cells which sometimes would give off heat, sometimes would not, gave off more energy than any known chemical reaction, yet did not produce the amount of neutrons or tritium expected in a nuclear fusion reaction.

What their cell has in common with this example is that it is pos-sible to store mechanical energy in a metal which is released by certain chemical or other processes. Strictly speaking, any metal is under some mechanical stress. It was without stress when it was red-hot liquid. But then it was cooled by some process. If it was cooled by quenching (dunking it in water), the outer layers solidified first, forcing the inner layers to solidify in restricted, stressed structures. That is why quenched or otherwise rapidly cooled metals (such as cast iron) are brittle. But even if the metal is cooled slowly by tempering or annealing, or if other processes (such as rolling) are used to let the molecules rearrange them-selves more naturally, stresses remain.