The reason energy is so hard to define is because it’s an abstract notion. In physics, the concept of “energy” is really just a kind of shorthand, a tool to help balance the books. Energy is always conserved (or converted into mass) so is incredibly useful in working out the results of any kind of physical or chemical process.
There are a lot of different kinds of energy in the universe, and energy has different forms. Our universe is made from energy and it is fundamental to the existence of everything!
- Common forms include
- Mechanical Energy.
- Heat (thermal) Energy.
- Solar (Sun) Energy.
- Chemical Energy.
- Electrical Energy.
- Nuclear Energy
- Potential Energy
Forms of energy can be converted from one to another.
Research about energy show there is much we don’t know about energy, that over 25% of the energy in the universe exists is in a form that cannot be explained. (e.g. dark matter)
There is no physical “essence” of energy, and “pure energy” as a concept can only be understood in a context of timelessness. Energy as humans view it is always carried by something, usually in the form of existence (mass) or movement. The Star Wars concept of “The Force” behind everything is quite a reasonable way to view energy!
There is no logical block to an understanding of energy as an equivalence with the creative force behind the entire universe, which if it has the characteristics of loving intent, can also be called God, or universal spirit.