Can all known forms of energy be reduced to the four known forces?

Question

For instance, can heat energy be reduced to electromagnetic energy in some cases, to nuclear energy in others? Can kinetic energy be reduced to electrical energy in some cases, or gravity in others? Since mechanics is the study of matter under the influence of forces, it seems to me that this is true. Thanks.

Answer 1

In some forced, probably not meaningful sense, perhaps.  Heat is a measure of kinetic energy, not directly related to nuclear fission or fusion.  Kinetic energy is unrelated to any force.  Potential energy is directly related to the position of objects relative to a force field.  But how do you reckon the energy equivalence of matter in E=mc²?

Answer 2

No.

A body in motion has energy even in the absence of all forces. Of course this kinetic energy - like the energy from any of the forces - is frame dependent.