Inspired by: Catherine Light
Energy is a definition created by people to better help create and understand the things around us. We can reliably reproduce certain phenomena like electricity. We don't understand its roots, but we understand various ways to manipulate it.
As such, we quantify different observable properties and correlate it with desirable results. 10 gallons of gas will get you about 200 miles. A crude relation, but it shows the kinds of things we relate.
At its roots, no person knows. We may have to increase our brains' capacity before the roots of energy can adequately be understood. There are many theories out there; the most related one for me is "String Theory".
String Theory proposes that a unified cross-dimensional ether exists and that the only time we currently see its influence and existence is when various qualities of the ether are coincident with other qualities (vibration modes). The vibration modes are not physical vibrations, the vibrations are just models that can be described mathematically that somewhat represent what could be happening. String theory has many shortcomings, but it describes certain qualities of "Energy" that are not described elsewhere. Each mathematic tool for modeling has its limitations.
As such, an atom might be described as hundreds, or an infinite number, of different vibration modes that oscillate around one another. Quark and other subatomic "particles of information" are different combinations of vibration modes.
Imagine the air around you, with hundreds of different properties associated with it: air pressure, static potential, inertial components, temperature, humidity, chemical constituents, electromagnetic content ...
Energy, from what I can glean, is sort of that way as we try to understand it. We create an indefinite number of different ways to define reproducible properties; but there seems to be an infinite number of different qualities that can be described; at least more than we can presently envision.
Nuclear Particles are not physical particles like a ball or a cat. A nuclear particle is an informational packet. Under certain circumstances, certain things can repeatedly occur. We don't truly understand what that "thing" is, but we have a book about that "thing" and as we learn new relationships, we add it to the book. We hope that one day our library of books will allow us to understand relationships with other "things" we have not already imagined.
Energy to me, is not humanly definable. We simply try to define how it affects us. In the future, if we broaden our mental capabilities, we might hope to understand the full scope of what energy is. If you can imagine a million minds sharing one extraordinarily large memory space and having no limit in lifetime.
If a black dot existed out in space and it had no properties other than existing and being a black dot. Would we be satisfied to understand that it is a black dot? No, because it does not provide us with any useful information. The term Energy is in-general only interesting to us because of what it can do for us; we tend to ignore all the things about energy that seem to exist that are not immediately useful.
Like there appears to be no such thing as empty space! There is no place that exists, that nothing exists! The ether we call "Energy" is everywhere and a part of everything, including what we call empty space.
You can ponder the basis of existence, which is what you are inferring when looking for the roots of energy. But of what use is it? If you want to do something useful with the concept of Energy, rather look at Quantum Mechanics and glean useful relationships that can relate the seemingly metaphysical. Quantum Mechanics can be used to find hidden but useful relationships, and it is much more easily understood; enough to be useful.
There are many thousands of people that have dedicated their lives to understanding the basic concept of energy. Currently, energy is a collection of relationships that can be reproduced in a laboratory. In our minds, energy is modeled as information. But using present techniques, energy will not be able to be modeled in our limited minds as it really exists; and therefore a proper definition is not presently possible.
