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What are photons made off?

  1. Feb 12, 2012 #1
    what are photons made off??

    this might be a stupid question but
    lets take a proton or a neutron these
    "elementary" particles are made up of quarks,
    does photons in its particle state follow the same pattern??
    if yes then what constitutes into a photon??

    thanks
     
  2. jcsd
  3. Feb 12, 2012 #2

    jtbell

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    Re: what are photons made off??

    In the Standard Model, photons are elementary particles, i.e. not composed of other particles.
     
  4. Feb 12, 2012 #3

    Redbelly98

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    Re: what are photons made off??

    Moreover, protons and neutrons are not considered elementary particles in the standard model.
     
  5. Feb 16, 2012 #4
    Re: what are photons made off??

    A photon is the quanta, the local 'particle' character, of a wave......[electromagnetic radiation, like light] ...hence it is composed of energy.

    More here:
    http://en.wikipedia.org/wiki/Photon
     
  6. Feb 18, 2012 #5
    Re: what are photons made off??

    But a photon has spin. So how can it be a wave?
     
  7. Feb 18, 2012 #6
    Re: what are photons made off??

    The photon is not a wave, it does however appear to act LIKE a wave in many circumstances due to the uncertainty in the movement of elementary particles
     
  8. Feb 18, 2012 #7
    Re: what are photons made off??

    Photon is not a wave it is a particle.
     
  9. Feb 18, 2012 #8

    HallsofIvy

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    Re: what are photons made off??

    Naty1 did NOT say a photon was a wave. He said it was a quantum of an electromagnetic wave.
     
  10. Feb 18, 2012 #9
    Re: what are photons made off??

    A photon can be sometimes considered the quanta of electromagnetic field. «Field» is not synonym for «wave»: both are different physical concepts.
     
  11. Feb 18, 2012 #10
    Re: what are photons made off??

    in my prior post, 'field' IS better than 'wave',,,,,I meant to draw no distinction here.

    "what constitutes [into] a photon??"

    What 'constitutes' any particle is it's measured/observed behaviors.....We create models to replicate those.
    So we can observe, describe, and model other characteristics of photons as well but those descriptions depend on what models we use....different model behaviors can manifest as 'spin' for example. What's 'really' there is
    anybody's guess unless we can smash something apart and look at the constituents...[which still seems like an odd approach, but it works. Like taking a car apart to see how its made by beating it!!!]

    from the link I posted:

    That's a mathematical statement.

    Meantime, string theory, another theory, also describes photon characteristics but I don't know enough about the math to divine exactly how [or if] AdS/CFT precisely relates string theory to gauge theory strictly enough to make direct characteristic 'spin' comparisons....

    Seems that things like spin pop out of mathematical models and clever physicsts exclaim "Oh that looks just like 'spin'...and so it is....but it takes a lot of work to compare the origins of such different mathematical model outcomes....
     
  12. Feb 18, 2012 #11
    Re: what are photons made off??

    A "photon" (that we perceive as a "particle) is generated by a change in the energy state of an electron. As the electron moves from a high energy state to a low energy state the energy that is lost by the electron is the "photon". It is a state of energy, mass without matter, how can it be a particle without matter?

    Paul
     
  13. Feb 19, 2012 #12

    Drakkith

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    Re: what are photons made off??

    A photon is just as much of a particle as an Electron is EXCEPT that it has no invariant mass. (Commonly known as "rest mass") Both photons and electrons have particle-like and wave-like properties, as the commonly performed Double-Slit experiment will show with either one. There is nothing that says a particle MUST be matter.
     
  14. Feb 20, 2012 #13
    Re: what are photons made off??

    Where does the photon get its matter? The electron has none to provide and preserve its existence yet the change in energy state is all that is required to make the photon.

    We perceive the effects of what we don't understand and make them understandable by expanding the improbable. Hiding behind the multiple definitions only delays the truer understanding of the reality of the universe.

    Photons only "behave" like particles and waves depending on the perceptions of the tests to which we subject them.

    Paul
     
  15. Feb 20, 2012 #14

    Nabeshin

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    Re: what are photons made off??

    I hope you realize that photons are generated by more than electronic transitions.

    You keep using the word 'matter', but I don't really know what you mean by it. I'd define matter as 'stuff made of hadrons and leptons', but apparently you seem to disagree. What exactly is this 'matterness' that you seem to think the photon has that is confusing you?
     
    Last edited: Feb 20, 2012
  16. Feb 20, 2012 #15

    Drakkith

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    Re: what are photons made off??

    Matter is typically defined as objects that have mass. A photon does not and isn't matter. In fact, the matter isn't "something" in and of itself, it is merely a way to classify things. Similarly a proton is a Hadron and an Electron is a Lepton. Photons are Bosons, a type of subatomic particle that has spin 0. Leptons, Quarks, and Bosons are the 3 types of fundamental particles that everything else is made up of. Matter is simply another type of classification.

    Nonsense. You simply don't know the differences in the terms that are used. And there is no "truer" understanding of reality other than science.

    No, they act like both a particle and a wave all the time.(Edit: Rather they act like waves and particles whenever appropriate, irregardless of whether or not we are observing them) We can see the wave-like part of them when we look correctly, and we pretty much always see the particle-like part when we interact with them during a measurement.
     
    Last edited: Feb 20, 2012
  17. Feb 21, 2012 #16
    Re: what are photons made off??

    If it walks like a duck, and talks like a duck, then (surely) it is a duck?!
     
  18. Feb 21, 2012 #17
    Re: what are photons made off??

    The OED defines quantum to mean an "amount; share; portion" of something. A portion of cake is ..er.. cake. So how can a quantum of an electromagnetic wave not be an electromagnetic wave?
     
  19. Feb 21, 2012 #18
    Re: what are photons made off??

    So we can't say what photons are made of? We can't even say if they are particles or waves or strings?
     
  20. Feb 21, 2012 #19
    Re: what are photons made off??

    How do you know that? How *can* you know that? You certainly can't observe them all the time, without the observation interfering with them...
     
  21. Feb 21, 2012 #20

    Drakkith

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    Re: what are photons made off??

    Nope. We can't 100% know this. However I don't believe the universe works one way when we observe something and another way when things interact without us to observe them.
     
  22. Feb 21, 2012 #21
    Re: what are photons made off??

    It walks like a duck, and talks a dog. The debate was then if it is a duck or a dog. I would say that a duck resembles it in the way a duck walks, and a dog resembles it in the way a dog talks. :tongue2:

    The problem is largely in the descriptors: real "particles" such as electrons can have wave behaviour, and real waves such as sound waves can have particle behaviour.
     
  23. Feb 21, 2012 #22
    Re: what are photons made off??

    For most practial applications you can forget about electromagnetic radiation being particles and just treat it as a wave as prescribed by Maxwells laws of electrodynamics. When you have light interacting with atoms or molecules they can typically only emit/absorb energy from the radiation in "chunks" corresponding to differences between energy levels in the atom/molecule.

    Maybe someone can remind me of when we need to treat electomagnetic radiation as consisting of particles?
     
  24. Feb 21, 2012 #23
    Re: what are photons made off??

    [/QUOTE]We perceive the effects of what we don't understand and make them understandable by expanding the improbable. Hiding behind the multiple definitions only delays the truer understanding of the reality of the universe.[/QUOTE]



    yes, sometimes....like dark matter and dark energy....Or "Is light a wave or a particle?" or the precession of Mercury.....that's often the start of a 'new discovery'....or attempts at least.

    well some things ARE 'improbable'...like quantum theory.....but if they turn out to be
    incorrect, meaning proven false, they are usually set aside and a new understanding is sought.

    I think you mean 'explanations' rather than definitions...but when first discovered an initial explanation is often incomplete, incorrect or only partially correct. For example when Einstein published his theory of general relativity, he did not see the unification of space and time into spacetime [that advance insight came from his college math professor, Minkowski] nor had he even solved in own equations [the first solution came from Karl Schwarzchild, I think]. And it took Einstein some ten years to uncover what he did publish...we learn stuff in pieceparts.

    I'd argue just the opposite: publishing or sharing a partial or incomplete theory or working with colleagues speeds up an improved understanding.....think of collaboration where multiple and conflicting perspectives and insights are argued out and a consensus is eventually reached.
     
  25. Feb 21, 2012 #24
    Re: what are photons made off??

    As is well-known in particle physics, photons are particles.

    Photons, in the Standard Model of particle physics are structureless. This mean they are not made of anything, but are a basic 'building block' of nature, as fermions and quarks.
     
  26. Feb 22, 2012 #25
    Re: what are photons made off??

    Lowest intensity radiation? You may have to assume photons proceed one-by-one in particle like fashion. For instance, there is a neat double-slit experiment where photons are detected one by one. Of course, the pattern they make (eventually) looks like an interference pattern, which can only (surely) come form waves. But they arrive one by one... :confused: Does even Feynman understand this stuff? :smile:
     
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