Rest mass of a photon

Discussion in 'Physics & Math' started by Magical Realist, Aug 30, 2019.

  1. Write4U Valued Senior Member

    Messages:
    20,069
    True, but then I qualify them as being more probative than declarative.
    The notion struck me that the speed of light is in fact a hard limit for a physical object to retain physical integrity.

    Did Einstein not say that an object at SOL gains so much mass that theoretically, an object travelling at SOL could not quantum refresh itself, because it would need all the energy in the universe to accomplish that feat. But if we consider the power of universal energy, what object could withstand such stress without disintegrating.

    That would explain the law that the more massive an object is, the more energy it needs and the more time it needs for quantum dynamics and that is controlled and restricted by the speed it can change quantum coordinates, while maintaining physical integrity.

    This seems to me in agreement to GR as well as SR, and I don't see the concept as overly exotic.....

    Please Register or Log in to view the hidden image!




    p.s. this might also lead to a logical conclusion that the BB was a massive singularity travelling at FTL and
    just exploding as the BB because it exceeded the limits of "c" and only after slowing to more moderate speeds (through cooling) did the quantum plasma fields gain physical mass eventually expressed as the elements....

    Please Register or Log in to view the hidden image!

     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. DaveC426913 Valued Senior Member

    Messages:
    18,935
    No. He did not.
     
    exchemist likes this.
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Write4U Valued Senior Member

    Messages:
    20,069
    You mean he left out the quantum bit?

    If he did not address that specifically, what would change in the message?

    Does reality not rest on quantum mechanics?
    Does speed not affect quantum mechanics?

    Can quantum mechanics function at faster than light? Can reality manifest itself at faster than light?
    Thanks for that little gem.
    (I assume this is an observation, rather than a theoretical proposition based on arbitrary assumptions.)

    IMO, this would tend to confirm at least the concept that "c" is a physical limit beyond which reality cannot exist in the form we experience it.
     
    Last edited: Aug 31, 2019
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Messages:
    13,077
    Not sure I would go with refresh itself which to me seems to imply a stop/start process

    Would prefer a continuous smooth process, no refreshing required

    Think I need to activate more brain cells, not just Huey Dewey and Louie, but the others are busy working on next Bali holiday, sprung on me, in 2 weeks time ahead of the planned November planned one

    More nuggets but unfortunately was slack with keeping references
    ******
    Because Planck Time is actually defined as the time it takes light to travel one Planck Length.
    *******
    The explanation Einstein used had borrowed from Planck’s equation and it basically tells us that light cannot be divided infinitely. Once you get to the smallest piece of light - a “photon” he called it - you cannot divide it any further.
    ******
    That's all I have at the moment

    Coffee time

    Please Register or Log in to view the hidden image!

     
  8. arfa brane call me arf Valued Senior Member

    Messages:
    7,832
    A Feynman diagram of a pair of fermions exchanging a single photon represents that the change in momentum of each fermion "is" the photon (the squiggly line), and the photon transfers real momentum from one massive particle to the other. Thus one fermion is a source of this exchange of momentum, aka a photon.

    Note that fermions such as electrons are sources of photons when they accelerate, implying that electrons can be in a rest frame.
     
  9. Write4U Valued Senior Member

    Messages:
    20,069
    But AFAIK quantum mechanics argues against a continuous smooth process.
    With "refresh" I wanted to indicate the process of quantum change as "a state" becoming regenerated as a "new state". A quantum event.

    I believe the expression is that Quantum Mechanics argues for "discrete energy quanta"
    Does that not suggets that if light itself propagates via QM that light and reality itself consist of energetic quanta as discrete non-linear packets
     
    Last edited: Aug 31, 2019
  10. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Messages:
    13,077
    Thinking thinking thinking

    coffee holiday coffee holiday coffee holiday

    Sorry what was the question? Oh yes

    Will get back to you sometime

    Please Register or Log in to view the hidden image!

     
  11. Write4U Valued Senior Member

    Messages:
    20,069
    Sorry, Michael,

    I've been forbidden to pursue this line of inquiry any further on pain of "banning".
     
  12. James R Just this guy, you know? Staff Member

    Messages:
    39,397
    That's currently an unsolved mystery.

    Maybe. Or maybe it's just a random parameter of our universe. Nobody knows yet.

    There's nothing amazing about that. It's like that because of how those two terms are defined.

    There's no need to invoke Planck units to say that. For example, the same statement is true if we measure lengths in light years and time in years. I don't think I need to mention that there's nothing universal about our year.
     
  13. James R Just this guy, you know? Staff Member

    Messages:
    39,397
    Every object travels along a worldline in spacetime. A worldline is just the entire history of a thing's spacetime coordinates.

    That's a kind of pop-science statement that is sort of half right and half nonsensical.

    Time never ceases to exist. What that statement is referring to, probably, is the idea that we see clocks slow down when they travel very fast, and if they could travel at the speed of light they would look - to us, watching them fly past - like they were stopped.

    No. Things following geodesics are explicitly not accelerating. That's what a geodesic means.

    4 dimensional motion along a worldline.

    First, think about the source of a regular object's momentum. $p=mv$, so is the "source" of momentum mass, or speed, or both? Does it make sense at all to ask about a source in this context?

    Next, consider the following equation from relativity:

    $E^2 = (pc)^2 + (mc^2)^2$,

    where $E$ is the total mechanical energy of an object with rest mass $m$ and (relativistic) momentum $p$. This equation applies even when $m=0$, in which case we have $p=E/c$.

    In other words, the momentum of a massless object is related to its total mechanical energy. Photons have energy, so they have momentum, too.
     
    Magical Realist likes this.
  14. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Messages:
    13,077
    OK

    Please Register or Log in to view the hidden image!

     
  15. paddoboy Valued Senior Member

    Messages:
    27,543
    That's simply the way it is, and anyway the job of science is not really asking why....
    this may help....
     
  16. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Messages:
    13,077
    I get that

    BUT

    the same can be said for the speed of light

    My question is about why is it that particular speed and not a 100 faster or slower?

    ie what is it about the rest of the Universe which constrains / consigns light to that speed?

    Please Register or Log in to view the hidden image!

     
  17. James R Just this guy, you know? Staff Member

    Messages:
    39,397
    This is false.

    Write4U received a warning not to post pseudoscience to our Science subforums. He is free to post "alternative" theories to our Alternative Theories subforum, and to discuss pseudoscience in our Pseudoscience forum, for instance.
    ----

    Write4U:

    What does that even mean?

    Define "reality", for starters. Then, explain how you can talk about the "speed of reality" and how that relates to the speed of light. While you're at it, trying explaining why reality needs to "refresh" itself, and what exactly goes on when the "refresh" happens. In the process, you'll no doubt have to get more specific about what you mean by "quantum change".

    When you write a sentence like that, it can look like it means something, but looks can be deceiving. If you're just pulling some jargon out of the air, you're not doing science.

    Forget quantum. Change implies time. Where does quantum come into it?

    Now you need to define "quantum refresh rate" and show exactly how it "turns out" as you say. Where can we find the mathematical or theoretical derivation of this result?

    Here we have a statement of belief, which is all well and good but not science. If this CDT thing is an actual scientific theory, have its authors actually published anything about this "refresh rate" business and so on?

    Slow down! Let's get to first base before we proceed to flights of fancy about implications.

    I'm not sure what that means.

    As far as I am aware, Einstein did not say that. In fact, I think you'll be hard pressed to find a single use of the term "quantum refresh" in any of Einstein's writings. But if you have the relevant quote, feel free to produce it.

    The power of universal energy???

    What are quantum coordinates?

    My impression is that you're having trouble distinguishing between science and vague imaginings of your own.

    That's a logical conclusion of what you said before, is it? I challenge you, then, to present the line of logical argument that gets us from A to B.

    Regenerated? What does that mean in this context?

    Also, at what point do you consider a quantum state to be "new"? Many quantum states evolve continuously. How much change equals "new", or a "regeneration"? And what kind of change?

    It doesn't suggest it as far as I'm concerned.

    I don't know what light propagating "via QM" means. I don't know what "reality" means in this context. I don't know what "non-linear" means in this context. To me, the whole thing reads like a bunch of buzz words strung together to make a sentence that sounds like it's scientific.
    ---

    Are you starting to understand why you received a warning for posting pseudoscience to the Science subforums yet?
     
    Seattle and exchemist like this.
  18. James R Just this guy, you know? Staff Member

    Messages:
    39,397
    And my answer was: nobody knows.
     
  19. sculptor Valued Senior Member

    Messages:
    8,466
    amen to that
     
  20. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

    Messages:
    13,077
    And further to that I asked about what possible aspects of the Universe might act to cause such a restriction

    You don't have any suggestions even, a possible suspect?

    Oh well I am not prone to fly untethered so I have a few more books to wade through

    Just thought I might find some more illumination

    Please Register or Log in to view the hidden image!

     
  21. Magical Realist Valued Senior Member

    Messages:
    16,602
    But I thought energy had mass--in accord with the equation E = mc2.
     
  22. Janus58 Valued Senior Member

    Messages:
    2,394
    The fact that the universe exists as a 4d manifold of three spatial and 1 temporal dimensions, the relationship between which are both frame dependent and non-Euclidean. For example, in Euclidean geometry, the sums of the interior angles of a triangle always sum to 180 degrees. However, in non-Euclidean geometry, they can add up to more or less than 180 degrees depending on what the "curvature" of the geometry is. "c" falls out of the particular relationship time and space have in our universe. If the relationship was different, we would get a different value for c. Asking why this particular value is like asking why the curvature of a particular non-Euclidean geometry has a certain value. It is what it is. Could the universe have had a different value for c? Maybe, but such a universe would likely look different than ours, and if it was a capable of, and contained an intelligent species, that species would also wonder why c had the particular value it did for that version of the universe.
     
  23. Janus58 Valued Senior Member

    Messages:
    2,394
    More accurately, energy shares certain properties with mass that under Newtonian Physics are only attributed to mass. In terms of momentum, energy has a "mass equivalence".
    The thing with E=mc^2 is that the m stands for a rest mass, at rest. It means that if you have x amount of rest mass, it can be converted to xc^2 amount of energy. It really just a special case of the more general purpose equation given by James R above:
    E^2 ' (pc)^2 +(mc^2)^2
    with p being momentum
    For an object at rest, p=0 and it reduces to E=mc^2
    For a photon with zero rest mass, it reduces to E=pc.
    And, for a photon, p= h/l, where p is Planck's constant and l the wavelength.

    Photons have energy and momentum, but zero rest mass.
     
    Magical Realist likes this.

Share This Page