the ontology of "Energy"

[Kuznetzova]

((Disclaimer. I would have posted this in a more relevant section of this forum, ie Metaphysics or Philosophy of Science. However, I have made the conscious decision that this topic is so pervasive in the modern cultural consciousness that it deserved to be promoted all the way to the top of the forum. I think you will agree.))


There are two different concepts of the word "energy" in the english language.

1) Conversational Energy

Conversational Energy is that energy of science fiction, which is often shot out of "energy guns". This concept is fuzzy, metaphorical, based in science-fictiony thinking and incorporated into New Age literature. This picture of energy as a sort of white-hot liquid which is located in space and moves really fast. That energy which is a substance, that appears in this inspirational tagline, "Everything is made of energy". This is the energy which the young stoner philosophers refer to as being ontologically indistinguishable from light. Those young forum regulars who refer to light as "pure energy". The New Age literature loves this concept of energy. New Age literature refers to energy as stuff which glows and shoots out of high voltage objects. Rest assured, it moves fast, it glows bright and is located in space.



2) Textbook Energy

Textbook energy is denoted as a capital E in physics textbooks and calculated as a quantity in academic settings. This energy appears in the famous equation E = mc^2. Despite the abuse flung upon this E by stoner philosophers and New Age spiritualists, this energy does not exist in space and is not equal to light, at all. Worse, it is not a substance whatsoever, but only an abstract quantity. Light is not energy, but rather there is a quantity of energy E, which is associated with the wavelength of a photon and Planck's constant. That is to say, light is not energy, but energy is E=hf, where f is the frequency of the photon. This quantity is not locatable in space. E is an abstract quantity which is carried around in the equations of physics. Textbook Energy is also associated with the motion of massive objects, but even in that case it is not "equal to" the motion. In that case the energy carried by the moving body is E= (1/2)mv^2, where v is the velocity of the object and m is its mass. Again, Textbook Energy is not motion, but is a quantity related to the motion by some transformative formula.


3) They are not the same!
Conversational Energy is not Textbook Energy. A glowing substance speeding through space may have its uses in cultural contexts, in science fiction, and in conceptualizations of the New Age literature. But in no shape or form should this be confused with the quantity E, which appears in Einstein's famous equation. Using a succinct example of the bowling ball at the 5th story window -- I will drive home to the reader that they cannot be the same thing. Imagine carrying a bowling ball up 4 flights of stairs to the 5th story of an office building. We do this on foot and then perch the bowling ball on a window sill. We leave the bowling ball sitting motionless on the window sill and depart the situation and the building. We leave the ball sitting on the window sill for three days. At the third day someone's cat jumps up onto the sill and bumps the ball with its paw. The bowling ball rolls out the window and starts a mad acceleration towards the sidewalk below. Within seconds, the bowling ball is smashing into the pavement, releasing copious amounts of energy. The collision creates sounds, heat, and flying fragments of the ball through the air, all which are manifestations of energy.

Enormous amounts of energy was released from the bowling ball upon impact. We can pose the following question to the New Ager, or the stoner philosopher (be that as it may) which they would be forced to answer:

During the three days in which the bowling ball was motionless, where was that energy?

If energy is a substance located at a place, where was that energy located during the three-day interim on the window sill? While these questions create a puzzling debate for the ontology of Conversational Energy, this situation is not a puzzle to Textbook Energy. A physics textbook says that your legs and arms put Potential Energy into the ball-window-pavement system during that hefty trek up four flights of stairs. This Potential Energy is not located anywhere, as it is merely a variable in an equation. That is to say, the amount of energy expended during the violent impact at the pavement was exactly the same energy "stored" by your legs during the stair climbing.

4) Potential Energy and its ontology
Where is Potential Energy , and how is it stored? Does it sneak unseen into a 5th dimension, and then released back into "our reality" at the correct moment? Nonsense. Potential Energy is not located anywhere, because energy itself is not located anywhere either, nor is energy "stored in a field" in some mystical manner. Potential Energy and Kinetic Energy are abstract quantities in the equations of mechanics. We can come full circle with the example of light. Light is not something like a little man racing a torch through the vacuum of space. In fact, the energy is associated instead with the frequency of the photon. (The forward speed of the photon is nowhere to be found in the equation) But what is frequency here? If it is philosophical metaphors that we seek, then the metaphor is not a glowy substance -- but a better metaphor would be a clock inside the photon itself. To be more accurate, our analogy would say energy is the rate at which this little clock is ticking. Going back to this little man racing visual aid -- the energy is not his hot glowing torch, instead the energy, E, of a our photon man is more like the rate of a pocketwatch around his neck. This rate (frequency) is independent of his forward motion. Whether our photon man be passing through air, or refracting through glass, it is the rate of his small watch that is the energy in this situation, not is barreling through space.

5) The ontology of "Energy"
If you had been hanging your philosophical hat on E = mc^2 up until now, believing the equation says that matter and energy are the "same thing", I suggest that you consider a different perspective. In textbooks, energy is not a substance. It is an abstract quantity that is always conserved in all interactions. What is it? What is energy? A quantity in an equation. That is the answer to that question. But you may complain this raises more questions than it answers. That complaint is justified. However, in a larger context, raising more puzzles like this may be the desirable outcome for philosophers and scientists alike.


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Further reading and citations

http://hyperphysics.phy-astr.gsu.edu/hbase/mod2.html#c3

http://www.ux1.eiu.edu/~cfadd/1160/Ch28QM/Photo.html

http://planning.cs.uiuc.edu/node707.html

http://www.physicsinsights.org/lagrange_1.html

http://arxiv.org/abs/physics/0004029

http://library.thinkquest.org/3471/ener ... lence.html

http://www.karlscalculus.org/einstein.html

http://www.mathpages.com/home/kmath601/kmath601.htm

[Bill Wiltrack]

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Could you expand upon this & possibly find more citations?




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[tillingborn]

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Could you expand upon this & possibly find more citations?




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Here's another one Bill:

I'm no physicist, but as I understand it, energy is essentially the damage something has the potential to do. On our scale we use Newton (E=1/2mv^2) and Einstein, (E=mc^2). You can use the first to work out how much of a dent a lump of uranium will make if you throw it at someone; with the latter you can tell how big a city it will flatten if it unravels.

So yes, energy is an abstract quantity in text books. And then it hits you.

[Kuznetzova]

In any case, energy is not the stuff supervillians shoot out of their fingers.

That's a fine concept for science fiction, but a misleading one for actual physics.

[tillingborn]

In any case, energy is not the stuff supervillians shoot out of their fingers.

Which, word for word, is what no one on this forum said.

That's a fine concept for science fiction, but a misleading one for actual physics.

Do you have any examples of actual physicists being so mislead?
If you ask me, and since you didn't, I'll tell you anyway, the simplest explanation for the existence of energy is that everything is made of Big Bang stuff. Assuming a cor blimey, where'd that come from, ex nihilo Big Bang, the stuff it's made of has the capacity to expand to it's current size in a mere 13.7 billion years. It's a big if, but if that is what the universe is made of, then 'particles' are made of the same stuff; in which case, it's little wonder they are so excitable.

[henry quirk]

Energy is just the measurement of the capacity to work (to move).

In other words: 'energy' is a construct folks use to measure work done, or, to measure work about to be done.

In other words: 'it takes x to move y across z'.

Nuthin' complicated about it...nuthin' to philosophize endlessly, uselessly, about.

'nuff said









As for what shoots out of supervillians: in my case, it's 'ejaculate' and it comes out of my penis.

[tillingborn]

Energy is just the measurement of the capacity to work (to move).

In other words: 'energy' is a construct folks use to measure work done, or, to measure work about to be done.

In other words: 'it takes x to move y across z'.

Nuthin' complicated about it...nuthin' to philosophize endlessly, uselessly, about.

'nuff said

Absolutely. On the other hand the mechanisms causing movement, or doing work, is a puzzle worth solving.

[Kuznetzova]

There is a pervasive sense that light is "pure energy" in some sort of naked form. That light is not energy at all was one of the central points of my original post. Maybe some examples from this forum itself would make this thread more relevant.

socratus
June 14th, 2013
where: "Objections, please."
infraction: refers to light as special form of energy. A pure form.

...
I want to say that on the one hand we have pure energy
of the quantum of light: E= h*f.
...

Godfree
June 22nd, 2013
where: "The universe expands"
infraction: Claims light is a form of energy. Copiously relies on the notion of energy as a substance.

...

Yes they do, light is a form of energy go back to the basics, you can't get something from nothing ,
to maintain that light beam you need energy, energy that will eventually decay ,

...

[Kuznetzova]

Energy is just the measurement of the capacity to work (to move).

In other words: 'energy' is a construct folks use to measure work done, or, to measure work about to be done.

In other words: 'it takes x to move y across z'.

Yeah. This is very close to the definition of an electron-volt in a random textbook. From reading many threads on this forum, it seems to me that the confusion with energy as a substance comes in especially in regards to Big Bang cosmology. People demand to know where the energy "came from". I think that demand might be partially reasonable since the potential energy is normally explained as the source of baryonic matter. (I think tillingborn already addressed this above.)

As for what shoots out of supervillians: in my case, it's 'ejaculate' and it comes out of my penis.

Skywalker didn't see this coming.