was "Gravity, A Function of Mass/Energy-Charge/Magnetism"
Tensile strain is one manifestation of negative energy. Another illustration is provided by the Stirling Engine. Most laymen familiar with engines such as the steam and internal combustion variety imagine that heat is needed to power an engine and would laugh at the idea of running an engine using blocks of ice for fuel. Yet with a Stirling engine one can do just that. Store enough ice in the old fashioned type of ice house during winter and one could run a Stirling Engine all summer. I am not suggesting this as a practical proposition but merely as an interesting example of negative energy, an analogy of tensile strain. Compressive strain is equivalent to heat. Tensile strain is equivalent to cold. Both heat and cold are sources of energy. Both heat and cold are deviations from ambient. It is the deviation that is important, not its sign. Another example, of course, is the earliest "steam" engine where negative, not positive, pressure was the internal agent of mechanical action. Frank Grimer
