[William Tell]

CollegeRepublican said: "The metal loading methods of cold fusion are harder for me to understand."

I can imagine that microscopic voids in the metal might contain air. The ultrasonic energy might cause the sides of a long, narrow void to move closer together in such a way as to mimic the conditions in the collapsing bubble in acetone; that is, the volume of the void could change rapidly under extremely high local forces causing super-heating of the air.

[CollegeRepublican]

That is a possiblility that I have never considered. I always assumed that the metal loading type of cold fusion had to do with a quirk in quantum mechanics if it were true.