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I know what the typical answer is. "Energy is the ability to do work." But a person who doesn't "understand" what energy is, this doesn't make any sense, especially when they watch videos on electrons in which the person in the video say that the electrons can basically teleport between energy levels by absorbing or releasing energy and that this can happen when they are hit with light particles that change frequencies (and thus color) depending on the change in energy. Then to be later told that photons are pockets of energy and that matter itself is a type of energy doesn't help either because that creates a paradox between matter and doing work. If matter is energy then matter is the ability to do work (which doesn't make any sense) and in my physics class I was taught that work is kgm^2/s^2 (which makes less sense if matter is energy). (sorry if the order was a bit strange, i'm trying to get my thoughts out)

The point of my question is that I've been told that energy is the ability to do work and that matter and photons are energy, so what is energy? Is it physical or mathematical? Is it just an essence that is stored in matter? Are there different types of energy (excluding dark energy)? Also, am I missing something? I'm really confused and it's annoying not understanding this, so please help me.


marked as duplicate by David Z Dec 18 '16 at 5:57

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    $\begingroup$ The thing is that this definition and the more subtle and all encompassing one involving the Noetherian conserved current related in invariance on time-translation are the real and proper definition. That no one starts with an intuition for this is immaterial. The best advice I have is to not worry about it for now. Once you have to employ the concept in enough places and ways you'll find that your ability to read the meaning of these definitions improves. $\endgroup$ – dmckee Dec 18 '16 at 5:38

A physical property.

A description of the portion of the universe being analized.

That which is conserved in time.

Further than that you'll probably go into philosophy.