Is 'Energy' Physically Real?

[Sunstone]

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a reality), or does it only refer to a scientific model? Please defend your answer to the death (and in the nude).

Please Note: "A scientific model is a representation of a particular phenomenon in the world using something else to represent it, making it easier to understand." The usefulness of a scientific model does not rest on its representational validity, but rather on its predictive value. A model can be quite different from the reality it models, and yet still be a good model if it can be used to make reliable predictions about future events. Essentially, scientific models are very good (albeit hidden) analogies. "X is like Y in that X and Y have in common this, this, and this." "Our climate model is like the atmosphere over time in that our climate model and the atmosphere over time have in common...." So is the term "energy" in physics the name of a physical thing, or the name of a model?

VERY IMPORTANT: The question is not whether something is "a form of energy", but whether there is something that "is" energy. So, if you say "chemical energy is a form of energy" you still have not told us what energy is. Ask yourself, "What do all forms of 'energy' have in common, and does what they have in common exist physically?" A correct answer to that question will give you a correct answer to the OP. (An incorrect answer will give you pure woo, also known as the Texas Republican Party's 2020 Campaign Platform. )






_______________________________
And now, for some music to make it up to you for such a tedious and boring OP....

 

[epronovost]

To make it obsenely short, energy in physics is defined as the capacity to do work. In other words, if something can do stuff, it's a form or other of energy. Energy is an ontological category of things.

 

[Skwim]

.

In looking around I came across this rather interesting take on energy that was published in COSMOS Magazine.

"[Energy] is one of the most basic concepts in physics, but also one of the hardest to define. Cathal O'Connell has a go.

'Any physics textbook will tell you energy is “the capacity to do work”. Then it usually goes on to explain that “work” is the action of moving something against a force. But isn’t this definition kind of unsatisfying? It’s a bit like Plato’s definition of man as a “featherless biped” – it’s hard to poke holes in the reasoning, but you can’t help but feel something is missing.

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 is no physical “essence” of energy, and no such thing as “pure energy”. Energy is always carried by something, usually in the form of movement.

The classic example of kinetic energy is a billiard ball rolling across a table. The heavier the ball, the faster it moves, the more energy it carries. In other words, the more painful it will be if it pops off the table and lands on your little toe.

Another form of kinetic energy is known as heat. The temperature of something is a direct measurement of how fast the atoms inside it are moving. In a hot cup of coffee, the water molecules are racing around at a fast clip, slowing down as the cup cools.

Throw an iron bar into the fire and its atoms start moving faster too, although in this case the atoms are bound in position, and so the movement is the form of a jiggling vibration.

Sometimes an object is pulled or pushed in a particular direction, but its movement is stopped by some other force. In this case, the object is said to have potential energy. Potential energy means the potential to move.

It’s a bit like a racing car driver pressing the accelerator with the handbrake still on – nothing much happens until she releases the brake.

A glass sitting on a table is being pulled down by the force of gravity. But any movement is being stopped by a much stronger force – the electrical repulsion of the atoms in the table. Give the glass a nudge off the table, though, and it falls.

What about chemical energy, electrical energy, or nuclear energy? These are a bit more complicated, but in the final analysis, all these forms of energy also involve a type of movement or a potential to move.

For example, lots of energy is locked, like a coiled spring, inside atomic nuclei. This energy can be released when a uranium nucleus splits in two. The two halves are both positively charged, and so just after the split they are electrically repelled by other another and fly apart. Thus the nuclear potential energy ends up as kinetic energy.

As the Russian physicist Lev Okun said, “The more basic is a physical notion, the more difficult to define it in words.” For energy, the best we can do is say it’s the capacity to cause movement.

And that should do us poor featherless bipeds just fine.' "
source

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Emphases mine.

.​

 

[9-10ths_Penguin]

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a reality), or does it only refer to a scientific model? Please defend your answer to the death (and in the nude).

Please Note: "A scientific model is a representation of a particular phenomenon in the world using something else to represent it, making it easier to understand." The usefulness of a scientific model does not rest on its representational validity, but rather on its predictive value. A model can be quite different from the reality it models, and yet still be a good model if it can be used to make reliable predictions about future events. Essentially, scientific models are very good (albeit hidden) analogies. "X is like Y in that X and Y have in common this, this, and this." "Our climate model is like the atmosphere over time in that our climate model and the atmosphere over time have in common...." So is the term "energy" in physics the name of a physical thing, or the name of a model?

VERY IMPORTANT: The question is not whether something is "a form of energy", but whether there is something that "is" energy. So, if you say "chemical energy is a form of energy" you still have not told us what energy is. Ask yourself, "What do all forms of 'energy' have in common, and does what they have in common exist physically?" A correct answer to that question will give you a correct answer to the OP. (An incorrect answer will give you pure woo, also known as the Texas Republican Party's 2020 Campaign Platform. )






_______________________________
And now, for some music to make it up to you for such a tedious and boring OP....

"Energy" describes reality, but often it describes the state of matter rather than a discrete physical thing.

For instance, when we get right down to it, "heat" is a term for a particular type of motion.

 

[Nakosis]

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a reality), or does it only refer to a scientific model? Please defend your answer to the death (and in the nude).

Please Note: "A scientific model is a representation of a particular phenomenon in the world using something else to represent it, making it easier to understand." The usefulness of a scientific model does not rest on its representational validity, but rather on its predictive value. A model can be quite different from the reality it models, and yet still be a good model if it can be used to make reliable predictions about future events. Essentially, scientific models are very good (albeit hidden) analogies. "X is like Y in that X and Y have in common this, this, and this." "Our climate model is like the atmosphere over time in that our climate model and the atmosphere over time have in common...." So is the term "energy" in physics the name of a physical thing, or the name of a model?

VERY IMPORTANT: The question is not whether something is "a form of energy", but whether there is something that "is" energy. So, if you say "chemical energy is a form of energy" you still have not told us what energy is. Ask yourself, "What do all forms of 'energy' have in common, and does what they have in common exist physically?" A correct answer to that question will give you a correct answer to the OP. (An incorrect answer will give you pure woo, also known as the Texas Republican Party's 2020 Campaign Platform. )






_______________________________
And now, for some music to make it up to you for such a tedious and boring OP....

IMO, if we can measure it, it's real. We can measure it by its effect on other things.

 

[Cooky]

Sounds like a lot of people tip-toeing around the fact that energy is not physically real.

 

[Cooky]

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a reality), or does it only refer to a scientific model? Please defend your answer to the death (and in the nude).

Please Note: "A scientific model is a representation of a particular phenomenon in the world using something else to represent it, making it easier to understand." The usefulness of a scientific model does not rest on its representational validity, but rather on its predictive value. A model can be quite different from the reality it models, and yet still be a good model if it can be used to make reliable predictions about future events. Essentially, scientific models are very good (albeit hidden) analogies. "X is like Y in that X and Y have in common this, this, and this." "Our climate model is like the atmosphere over time in that our climate model and the atmosphere over time have in common...." So is the term "energy" in physics the name of a physical thing, or the name of a model?

VERY IMPORTANT: The question is not whether something is "a form of energy", but whether there is something that "is" energy. So, if you say "chemical energy is a form of energy" you still have not told us what energy is. Ask yourself, "What do all forms of 'energy' have in common, and does what they have in common exist physically?" A correct answer to that question will give you a correct answer to the OP. (An incorrect answer will give you pure woo, also known as the Texas Republican Party's 2020 Campaign Platform. )






_______________________________
And now, for some music to make it up to you for such a tedious and boring OP....

It's actually a brilliant question.

 

[Sunstone]

To make it obsenely short, energy in physics is defined as the capacity to do work. In other words, if something can do stuff, it's a form or other of energy. Energy is an ontological category of things.

Really? How can a "capacity" be an ontological category? Are you speaking in a metaphysical sense?

 

[PureX]

To make it obsenely short, energy in physics is defined as the capacity to do work. In other words, if something can do stuff, it's a form or other of energy. Energy is an ontological category of things.

So, then, we could say that energy is the "will for something to happen"?

 

[Polymath257]

I'm sure that I don't have a good definition of 'physically real' that doesn't include energy.

At least part of the problem is deciding whether 'properties' like mass, momentum, angular momentum, charge, polarity, and spin are 'physically real' or not. if they are, then energy is simply one of the properties that is included in this list. I usually do think of these properties as physically real, so I would consider energy to be physically real.

Of course, you can also ask whether an electron is 'physically real'. Certainly, electrons don't act like anything *classical*, but if they are not physically real, then I have no idea what would be.

 

[bobhikes]

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a reality), or does it only refer to a scientific model? Please defend your answer to the death (and in the nude).

Please Note: "A scientific model is a representation of a particular phenomenon in the world using something else to represent it, making it easier to understand." The usefulness of a scientific model does not rest on its representational validity, but rather on its predictive value. A model can be quite different from the reality it models, and yet still be a good model if it can be used to make reliable predictions about future events. Essentially, scientific models are very good (albeit hidden) analogies. "X is like Y in that X and Y have in common this, this, and this." "Our climate model is like the atmosphere over time in that our climate model and the atmosphere over time have in common...." So is the term "energy" in physics the name of a physical thing, or the name of a model?

VERY IMPORTANT: The question is not whether something is "a form of energy", but whether there is something that "is" energy. So, if you say "chemical energy is a form of energy" you still have not told us what energy is. Ask yourself, "What do all forms of 'energy' have in common, and does what they have in common exist physically?" A correct answer to that question will give you a correct answer to the OP. (An incorrect answer will give you pure woo, also known as the Texas Republican Party's 2020 Campaign Platform. )






_______________________________
And now, for some music to make it up to you for such a tedious and boring OP....

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a

Energy is motion at the molecular level. It is not a physical thing but causes physical things to move. Its likely cause is that like physical things repel. This repulsion caused different types of energy and an important development that opposite types of energy attract. As more and more things came to be colisions became common and motion is the norm. IMHO

 

[Altfish]

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a reality), or does it only refer to a scientific model? Please defend your answer to the death (and in the nude).

Please Note: "A scientific model is a representation of a particular phenomenon in the world using something else to represent it, making it easier to understand." The usefulness of a scientific model does not rest on its representational validity, but rather on its predictive value. A model can be quite different from the reality it models, and yet still be a good model if it can be used to make reliable predictions about future events. Essentially, scientific models are very good (albeit hidden) analogies. "X is like Y in that X and Y have in common this, this, and this." "Our climate model is like the atmosphere over time in that our climate model and the atmosphere over time have in common...." So is the term "energy" in physics the name of a physical thing, or the name of a model?

VERY IMPORTANT: The question is not whether something is "a form of energy", but whether there is something that "is" energy. So, if you say "chemical energy is a form of energy" you still have not told us what energy is. Ask yourself, "What do all forms of 'energy' have in common, and does what they have in common exist physically?" A correct answer to that question will give you a correct answer to the OP. (An incorrect answer will give you pure woo, also known as the Texas Republican Party's 2020 Campaign Platform. )






_______________________________
And now, for some music to make it up to you for such a tedious and boring OP....

Energy is defined as

Power x Time

 

[Revoltingest]

To make it obsenely short, energy in physics is defined as the capacity to do work. In other words, if something can do stuff, it's a form or other of energy.

That's not quite accurate. A simple example....
You have a system in which everything is at the same
level of energy, ie, same temperature, same height, the
same in the sense that energy won't flow from one place
to another. Elements in it would have thermal energy in
the atoms vibrating. But no work can be done (ie, a
heat engine cannot do work).
Alas, I can't give you a good definition for all energy.
I can think of examples, but I can't generalize from them.

 

[epronovost]

That's not quite accurate. A simple example....
You have a system in which everything is at the same
level of energy, ie, same temperature, same height, the
same in the sense that energy won't flow from one place
to another. Elements in it would have thermal energy in
the atoms vibrating. But no work can be done (ie, a
heat engine cannot do work).
Alas, I can't give you a good definition for all energy.
I can think of examples, but I can't generalize from them.

That system is impossible according to thermodynamic laws. All systems change.

 

[Revoltingest]

That system is impossible according to thermodynamic laws. All systems change.

Which laws?
I just gave you a simple system to illustrate how energy & work are related.
But even our entire universe could achieve what's called "heat death".
Simply put....
That would be when everything is the same temperature.
(Maximum entropy, ya know.)
It would be the end of anything happening.

But that's just how things appear.
The universe could turn out to have unanticipated complexities.

 

[exchemist]

In physics, does the term "energy" refer to a reality (such as the term "heat" refers to a reality), or does it only refer to a scientific model? Please defend your answer to the death (and in the nude).

Please Note: "A scientific model is a representation of a particular phenomenon in the world using something else to represent it, making it easier to understand." The usefulness of a scientific model does not rest on its representational validity, but rather on its predictive value. A model can be quite different from the reality it models, and yet still be a good model if it can be used to make reliable predictions about future events. Essentially, scientific models are very good (albeit hidden) analogies. "X is like Y in that X and Y have in common this, this, and this." "Our climate model is like the atmosphere over time in that our climate model and the atmosphere over time have in common...." So is the term "energy" in physics the name of a physical thing, or the name of a model?

VERY IMPORTANT: The question is not whether something is "a form of energy", but whether there is something that "is" energy. So, if you say "chemical energy is a form of energy" you still have not told us what energy is. Ask yourself, "What do all forms of 'energy' have in common, and does what they have in common exist physically?" A correct answer to that question will give you a correct answer to the OP. (An incorrect answer will give you pure woo, also known as the Texas Republican Party's 2020 Campaign Platform. )






_______________________________
And now, for some music to make it up to you for such a tedious and boring OP....

No it's not the name of a model. It is a property of a physical system, like momentum. Momentum is not a model, though it features in a number of models. A model in science has to be able to predict what observations we should expect to be able to make. A mere property, like momentum - or energy - can't do this by itself.

As for the question about reality, do you think momentum is real? If you do, then you must also consider energy to be.
If, on the other hand, you think momentum is just a derived concept that is useful for analysing problems in physics, then you are at liberty to think of energy in the same way.

 

[exchemist]

So, then, we could say that energy is the "will for something to happen"?

Do you think will and capacity are synonyms?

 

[exchemist]

Which laws?
I just gave you a simple system to illustrate how energy & work are related.
But even our entire universe could achieve what's called "heat death".
Simply put....
That would be when everything is the same temperature.
(Maximum entropy, ya know.)
It would be the end of anything happening.

But that's just how things appear.
The universe could turn out to have unanticipated complexities.

Possibly what @epronovost may have in mind is that even in that scenario there would still be a (Maxwell-Boltzmann) distribution of energy among the molecules making up the system. This will be true for any system that is above absolute zero.

 

[epronovost]

Which laws?
I just gave you a simple system to illustrate how energy & work are related.
But even our entire universe could achieve what's called "heat death".
Simply put....
That would be when everything is the same temperature.
(Maximum entropy, ya know.)
It would be the end of anything happening.

But that's just how things appear.
The universe could turn out to have unanticipated complexities.

Sorry I missunderstood your example.

 

[Revoltingest]

Possibly what @epronovost may have in mind is that even in that scenario there would still be a (Maxwell-Boltzmann) distribution of energy among the molecules making up the system. This will be true for any system that is above absolute zero.

I'm sure that's what he meant.
Still...you can have energy, but not be able to do work.