What is energy: subatomic particle or abstract concept?

[gib65]

I've always been confused by the whole idea about what energy is. I mean, on the one hand, you have the classical definition which runs something along the lines of an abstract concept about what makes rigid bodies move and behave. But on the other hand, modern physics would have it that energy is actually made up of fundamental particles (photons or whathaveyou). The confusing thing about it for me is this: If energy is really made out of particles and these particles can move through space, then what accounts for their motion? What's even more confusing is that string theory would have it that these particles are no different that matter particles except for the frequency with which they vibrate. So what seems to make more sense to me is to say that photons and all other energy particles (if there are any others) and matter particles are actually two different breads of the same thing, and that energy proper (i.e. the kind referred to according to the classical definition) is something entirely different, something that interacts with particles of all kinds such that it accounts for their motion.

 

I'm sure I've missed something here. Please tell me where I'm going wrong.

 

Gib

[ed84c]

I think of photons of a way of displaying energy, like a TV is a way of displaying radio waves.

[swansont]

Energy is the capacity to do work. It's not particulate, though it can be quantized.

[gib65]

Fair enough, but then what is meant when scientists talk about photons traveling through space? Or electromagnetic waves having an absolute velocity of 300,000km/s? Or string theory postulating photons to be strings vibrating at a certain frequency akin to matter particles vibrating at different frequencies? It just seems to me like if any of these are truisms, there's no alternative but to conceive of energy as something that must take on some of the properties of matter, such as positions and motion through space, without occupying a rigid body. If that's the case, what can be said of the kenetic responsible for making motion possible in the first place? Can energy possess energy?

[MolecularMan14]

Energy is the capacity to do work. It's not particulate, though it can be quantized.

Right

Energy-

the capacity of a physical system to do work; the units of energy are joules or ergs.

[swansont]

An object can have energy without being energy.

[gib65]

SO, in other words, energy is an abstract concept. Therefore, all constructs that represent energy, such as "photons", "electromagnetic energy", the vibrating string model of energy particles, etc., are likewise abstract concepts? IS it just that they seem to exhibit some of the properties of matter? Is this science's stance on it? If this is true, why not just assume photons and other such energy particles along with electromagnetic radiation, are actually not the same phenomena as that refered to by the classical definition (energy is the capacity to do work). In other words, photons, electromagnetic radiation and such are not energy or matter, but something entirely different. Something that exists in our universe which is much harder for the human senses to detect than matter, and uses energy (the classical kind) in a similar way as matter.

[ed84c]

and what does that forthold for gluons?

[[Tycho?]]

SO, in other words, energy is an abstract concept. Therefore, all constructs that represent energy, such as "photons", "electromagnetic energy", the vibrating string model of energy particles, etc., are likewise abstract concepts? IS it just that they seem to exhibit some of the properties of matter? Is this science's stance on it? If this is true, why not just assume photons and other such energy particles along with electromagnetic radiation, are actually not the same phenomena as that refered to by the classical definition (energy is the capacity to do work). In other words, photons, electromagnetic radiation and such are not energy or matter, but something entirely different. Something that exists in our universe which is much harder for the human senses to detect than matter, and uses energy (the classical kind) in a similar way as matter.

 

A photon is electromagnetic radiation. They are the same thing.

 

I dont see how energy is an abstract concept. Seems pretty non-abstract to me. Anyway, there is no reason for your ideas to be correct. The concept of energy and work work just fine with photons, there is no reason to believe there is a problem with the theory.

[Rasori]

the units of energy are joules or ergs.

[random bad joke]Hence the reason we say "ERRRRRGGG!" when we try to pick up something heavy. [drum thing that's always done after a joke][/random bad joke]

[Ophiolite]

[random bad joke]Hence the reason we say "ERRRRRGGG!" when we try to pick up something heavy. [drum thing that's always done after a joke'][/random bad joke]

That was a real jewel. (Joule?)

[Sorcerer]

Was my groan energy or did it contain energy?

[gib65]

SEE!!! That's exactly the question I'm asking, except in my question, replace "groan" with "photons/electromagnetic radiation" (yes, I know they are the same thing).

 

Anyway, to Tycho?, I'd just like to say the following:

 

1) My post does not express "my idea" as you put it. I'm asking a question, not proposing a theory. What I was asking was if the "photons-as-third-entity-apart-from-matter-and-energy" is really the way the scientific community understands it. If so, then, for me, there is no confusion, but if not, I'm still confused. I certainly don't believe that I can overthrow nearly 100 years worth of quantum theory and experimentation just because it doesn't make sense to me.

 

2) I don't know how you conceive of the concept of energy, and it very well may be non-abstract to you. I personally, however, find it difficult to conceive of "the capacity to do work" as non-abstract. Let me give you the following scenario to illustrate:

 

Say you shine a flash light in empty space with minimal gravitational influence. Photons will be emitted from the flash light at a speed of 300,000 km/s. So let's denote the time the photons were emitted as t0 and let's denote t1 to be an hour ahead of t0. This means that within the time of t1-t0, the photons will have travelled 1,080,000,000 km. Let's denote the position at this distance as p1 and the point of departure for the photons as p0. Now, to say that at time t1, the photons are at position p1, this can be understood in a non-abstract way. I conceive of these entities called "photons" that have an actual position in space and time, and change their positions as a function of time, hence exhibiting motion. This is non-abstract in much the same way as matter. However, if I refere to the classical definition of "the capacity to do work", it just doesn't work the same way. I can't point to a position in space and say that at time t1 the capacity to do work will be right there, or that at time t1 > tx > t0 the capacity to do work will be between p0 and p1, or that the capacity to do work is travelling at 300,000 km/s at time tx. Do you see the problem? It would be just like taking some property of some concrete object like, for instance, the hardness of a brick or the roundness of a ball, and say that it is currently moving through space with a determinable position at some given time WITHOUT THE BRICK OR BALL TO GO ALONG WITH IT.

 

3) I'm sorry if my question offended you. Of course, it may just be my skewed interpretation, but your post sounded a little harsh. I so happen to be a very curious fellow, and as I'm sure you've probably noticed by now, I like to keep reiterating my questions in different forms until I get a satisfactory answer (even if that may be "I don't know"). So just to let you know, what satisfies as an answer for me is something that fills in the gap which my questions try to point out (and I try my best to make it clear). What doesn't work is either 1) a reiteration of the problem or 2) a dagmatic "it-just-makes-sense-and-your-conception-of-it-is-wrong" answer. But again, I may be way off base here assuming your response was harsh, and if I am, I sincerely apologize.

 

Gib

 

PS -

and what does that forthold for gluons?

 

That's another question I have: What are gluons?

[Severian]

Photons are not energy - they contain energy. In other words, their energy is a property of their state. In fact, every particle contains energy, whether a photon, an electron, quark, gluon etc.

 

Gluons are the force carriers of the strong nuclear force, just as photons are the force carriers of electromagnetism.

[gib65]

Ah! That makes sense! Thank you.