Are photons energy? What is energy, anyway?

Discussion in 'Physics & Math' started by origin, Aug 19, 2019.

Thread Status:
Not open for further replies.
  1. arfa brane call me arf Valued Senior Member

    Messages:
    7,832
    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.
     
    Last edited: Sep 23, 2019
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Write4U Valued Senior Member

    Messages:
    19,970
    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.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. origin Heading towards oblivion Valued Senior Member

    Messages:
    11,868
    A field does not consist of particles. In QFT a disturbance in the field is what we call a particle.
     
    exchemist and Write4U like this.
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Neddy Bate Valued Senior Member

    Messages:
    2,546
    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.
     
  8. James R Just this guy, you know? Staff Member

    Messages:
    39,237
    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.
     
  9. Write4U Valued Senior Member

    Messages:
    19,970
    This is why I call this unrealized property, "potential", or "that (essence) which may become reality".
    IMO, that fits very nicely.
     
  10. James R Just this guy, you know? Staff Member

    Messages:
    39,237
    No.

    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.

    Again, no. Photons are not energy differences.
     
  11. James R Just this guy, you know? Staff Member

    Messages:
    39,237
    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.
     
  12. James R Just this guy, you know? Staff Member

    Messages:
    39,237
    Glad to hear that this thread was useful to somebody, at least.
     
  13. Write4U Valued Senior Member

    Messages:
    19,970
    I believe the term is,"being in love", under the influence of love chemicals, such as pheromones, oxytocin.
    https://www.webmd.com/sex-relationships/news/20131125/how-the-love-hormone-works-its-magic#1
     
  14. Write4U Valued Senior Member

    Messages:
    19,970
    Question: when a particle is in it's "wave state", is it energy or does it have energy?
     
  15. James R Just this guy, you know? Staff Member

    Messages:
    39,237
    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.
     
  16. James R Just this guy, you know? Staff Member

    Messages:
    39,237
    I think you're losing sight of the thread topic and getting distracted into irrelevancies.
     
  17. Write4U Valued Senior Member

    Messages:
    19,970
    Is the particle/wave duality an obscure phenomenon?
    thank you, yes it was.
    Thank you. That was not clear to me yet.

    Question: Do waves have energy?
    https://www.sciencelearn.org.nz/resources/120-waves-as-energy-transfer
     
    Last edited: Sep 24, 2019
  18. Write4U Valued Senior Member

    Messages:
    19,970
    Really, what were you doing talking about it at some length? Just a throw-away?
     
    Last edited: Sep 24, 2019
  19. Write4U Valued Senior Member

    Messages:
    19,970
  20. arfa brane call me arf Valued Senior Member

    Messages:
    7,832
    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?
     
  21. arfa brane call me arf Valued Senior Member

    Messages:
    7,832
    Yes they are, to an electron that loses energy.
     
  22. arfa brane call me arf Valued Senior Member

    Messages:
    7,832
    Oh really? What point is that?
     
  23. arfa brane call me arf Valued Senior Member

    Messages:
    7,832
    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.

    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.
    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.
     
    Last edited: Sep 24, 2019
Thread Status:
Not open for further replies.

Share This Page