Are photons energy? What is energy, anyway?

[arfa brane]

What is energy seems to depend on what you mean by "a particle".

But as I think I understand it, every particle in the SM is a form of energy, it's an excitation of a field which "has" energy in it.
So if you say an electron in a potential well oscillates at discrete energy eigenvalues, you also mean they emit and absorb the difference in energy as photons.

But no, photons carry energy, they also have "other properties". Yep, all the properties correspond to a quantum of electromagnetic energy with a definite frequency in the frame of some electron or other charged particle. It's essentially a chunk of U(1) symmetry.

Why photons propagate at c (in a medium with only virtual particles in it) is a different question to whether they're a form of energy (which if every quantum particle is, then that follows).

But photons "are" the energy differences in QHOs. This is one way to explain why photons are annihilated by an absorption mechanism. A single oscillator absorbs all the photon's energy (and the photon) when resonance occurs.

 

[Write4U]

Do you find it equally hard to reconcile the idea that love is not stuff, despite the fact that people carry it around in their hearts?

Is that not a bit simplistic?
Emotions are chemical states which are produced by observation and empathic auro-responses. Love is an "emotion", a product of bio-chemical reactions and does not reside in the heart, but in the brain.
The faster beating of the heart is a secondary expression of empathic responses.

 

[origin]

Question; Do fields consist of particles or do particles emerge from disturbances in a pre-existing field?

A field does not consist of particles. In QFT a disturbance in the field is what we call a particle.

 

[Neddy Bate]

I am happy to admit that all of this has taught me that energy is a property of things, not an actual substance of any sort.

 

[James R]

Incidentally, I think I know why paddo stopped posting in this thread. He got the same answer as you, Origin and I have been giving, on the dot net site: https://www.scienceforums.net/topic...ave-mass/page/3/?tab=comments#comment-1116708

Interesting. Of course, so far he hasn't been big enough to come here and admit he was wrong. That's if he believes the answer he got over there, of course. Maybe he's going to keep searching until somebody gives him the answer he'd prefer.

 

[Write4U]

I am happy to admit that all of this has taught me that energy is a property of things, not an actual substance of any sort.

This is why I call this unrealized property, "potential", or "that (essence) which may become reality".
IMO, that fits very nicely.

 

[James R]

What is energy seems to depend on what you mean by "a particle".

No.

But as I think I understand it, every particle in the SM is a form of energy...

No particles are forms of energy, for reasons I have explained to you many times, carefully and explicitly. If you're not going to listen, I think I'm done talking to you.

But photons "are" the energy differences in QHOs.

Again, no. Photons are not energy differences.

 

[James R]

Is that not a bit simplistic?
Emotions are chemical states which are produced by observation and empathic auro-responses. Love is an "emotion", a product of bio-chemical reactions and does not reside in the heart, but in the brain.
The faster beating of the heart is a secondary expression of empathic responses.

You're just reinforcing the point I was making. Love isn't the "stuff". Love is a concept. The "stuff" in that example may be bio-chemicals, the brain and so on. The point is: being able to have love doesn't make somebody the same as love.

 

[James R]

I am happy to admit that all of this has taught me that energy is a property of things, not an actual substance of any sort.

Glad to hear that this thread was useful to somebody, at least.

 

[Write4U]

The point is: being able to have love doesn't make somebody the same as love.

I believe the term is,"being in love", under the influence of love chemicals, such as pheromones, oxytocin.

Researchers think they may have found a clue in oxytocin, a hormone released during sex and other intimate gestures like hugging or holding hands that's been proven to strengthen social bonds in other mammals.

They found that the hormone appears to boost men's attraction to their mate -- even when presented with pictures of other women.

"Oxytocin triggers the reward system to activate on the partner's face, the presence of the partner," said study author Dr. Rene Hurlemann, a professor of psychiatry at the University of Bonn, in Germany.

https://www.webmd.com/sex-relationships/news/20131125/how-the-love-hormone-works-its-magic#1

 

[Write4U]

Question: when a particle is in it's "wave state", is it energy or does it have energy?

 

[James R]

when a particle is in it's "wave state", is it energy or does it have energy?

What do you mean? When is a particle in its "wave state"?

Particles are not energy. Is that not clear to you yet? Waves aren't energy, either.

 

[James R]

I believe the term is,"being in love", under the influence of love chemicals, such as pheromones, oxytocin.

I think you're losing sight of the thread topic and getting distracted into irrelevancies.

 

[Write4U]

What do you mean? When is a particle in its "wave state"?

Is the particle/wave duality an obscure phenomenon?

Particles are not energy. Is that not clear to you yet?

thank you, yes it was.

Waves aren't energy, either

Thank you. That was not clear to me yet.

Question: Do waves have energy?

Waves as energy transfer. In electromagnetic waves, energy is transferred through vibrations of electric and magnetic fields.

In sound waves, energy is transferred through vibration of air particles or particles of a solid through which the sound travels.

In water waves, energy is transferred through the vibration of the water particles

https://www.sciencelearn.org.nz/resources/120-waves-as-energy-transfer

 

[Write4U]

I think you're losing sight of the thread topic and getting distracted into irrelevancies.

Really, what were you doing talking about it at some length? Just a throw-away?

 

[Write4U]

This may be of interest in context.

Energy and Conservation in Physics

http://www.math.utah.edu/~heidi/energy0.html

 

[arfa brane]

No particles are forms of energy, for reasons I have explained to you many times, carefully and explicitly. If you're not going to listen, I think I'm done talking to you.

Can you explain then, at least for just me, what do you think the phrase "a form of energy" refers to? Given that you haven't agreed that heat is a form of energy, very unlike what most textbooks say.

And can you answer the question: what does the zero point energy of a field correspond to? How does a field have energy, or carry it?

 

[arfa brane]

Again, no. Photons are not energy differences.

Yes they are, to an electron that loses energy.

 

[arfa brane]

We can agree that the energy of a quantum harmonic oscillator is quantised - i.e. only certain numerical values are possible. But, again, that's beside the point.

Oh really? What point is that?

 

[arfa brane]

The propagating electric and magnetic fields, you mean? When those (physical) electrons were made to oscillate, they created a self-propagating disturbance in the electromagnetic field, just like when you throw a rock into a pond it creates a self-propagating wave in the pond.

That is a really, really poor analogy. It suggests that I can create an electric current in a wire, and the electromagnetic field around it exists before the current does.

That I can generate electric and magnetic fields when I like, suggests strongly that the fields don't exist before I get electrons to generate them; there is no "pond full of water", but there is a vacuum.

What happens to the photon when it is absorbed is: it disappears. What happens to its energy is that its energy is moved from column A to column B in somebody's table of energies.

No, what happens to its energy if a charged particle absorbs it completely, is it becomes momentum for that particle. Particles don't have columns in them.

In QFT, photons are excitations of the electromagnetic field, which exists everywhere in space.

That isn't quite how it goes, sorry.
The electromagnetic field (Coulomb field) of a charged particle has been propagating through space since the particle was created. Every charged particle has it's own field. You seem to overlook that every time you trot something out like this.