Antimatter (Score 1)

Light sabers do not rely on heat but the elimation of matter by an antimatter light saber "blade". That's why there is no splashing residue to scar the Jedi and why 2 antimatter light saber blades can clang against each other without damage. The humming sound the saber makes is a result of the atmospheric matter (air molecules) being destroyed as they come in contact with the antimatter blade.