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I "Light is wave-like and particle-like" --- Why this is wrong?

  1. Apr 3, 2016 #1
    It's often said that light has both "wave-like" and "particle-like" properties, that light is both "wave-like" and "particle-like." But such a concept is fundamentally out of sync with reality. For, while it's true that light exhibits "particle-like" properties, the same cannot be said about "wave-like" properties. Real waves aren't "wave-like" any more than a real duck is a manifestation of being "duck-like." "Particle-like?" Yes, because photons have no rest mass. "Wave-like?" Uh, no, it's a real wave.

    Conceptually, the more correct thing to say is that light has both particle-like and wave properties. Symmetry shouldn't be artificially inserted.
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  3. Apr 3, 2016 #2


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    The description is not limited to light, everything can look "wave-like" and "particle-like".
    With a wave you cannot describe the photo-effect, for example.

    All those things are attempts to describe quantum mechanics to a lay audience. They are not the actual physics, which deals with quantum objects in a purely quantummechanical way.
  4. Apr 3, 2016 #3
    Okay, but I think you're missing the point. When evidence exists of light as a wave, e.g. the double-slit experiment, we're not talking about wave-like movement. We're talking about real wave movement. But when evidence exists of light "as a particle," the opposite is the case. We're not talking about a real particle, since real particles have rest mass. We're talking about particle-like attributes.

    And what? All that means is that light is in a particle-like form whenever it's being either emitted or absorbed by matter.

    Then physicists should change the way they attempt to explain the duality of light to lay audiences. Because to suggest that light has both "wave-like and particle-like" properties is inaccurate and misleading. It presents the problem as symmetrical, when it isn't. And in doing so it creates a problem where one doesn't exist.

    Light is in a particle-like form when it's in contact with matter, and is a wave when it's in movement between particles of matter. What's so hard about that?
  5. Apr 3, 2016 #4
    You are supposing properties and attributes "that don't exist"... just "contact with matter" needs lots of attention.
    Someone will come in shortly to mention that quantum entities don't have properties or attributes in the "usual" way.
  6. Apr 3, 2016 #5
    Well we know that when light interacts with matter, it's either emitted from the matter or absorbed by the matter. So how 'bout this:

    Light is in a particle-like form in its emission from matter, upon which it transforms into a wave in its movement from the matter, and back again into its particle-like form in its absorption back into matter.
  7. Apr 3, 2016 #6
    Perhaps it's best to say that quantum objects are neither waves nor particles.
    They are quantum objects whose behaviour *resembles* classical waves or particles depending on the situation.
  8. Apr 3, 2016 #7
    Good point.
  9. Apr 3, 2016 #8
    Human brains are good at using metaphor and simile too describe something that otherwise doesn't make sense. Or to fill in missing pieces of an observation. Don't know if that's a good thing or a bad thing. Maybe the quote, "You can't handle the truth!!" from I-forget-the-movie explains this phenomenon. I've always wondered if other animals do this.
  10. Apr 3, 2016 #9
    I think you're falling into the trap of the false symmetry. While manifestations of light resemble classical waves, they never resemble classical particles...because classical particles have rest mass. When light is demonstrated to be in a wave-form, it's not a flawed wave-form. As far as we can tell, it's simply a wave-form as we know waves. But whenever light is demonstrated to be in a "particle-form," it is an inherently and fundamentally flawed particle-form because it has no rest mass.

    The false symmetry expressed in your words is part of the reason why people in general, physicists included, overlook the simple solution to the "duality of the theory of light." Namely, that it's light itself that has the dual nature, not in some mysterious way, but simply in that light transforms from one form into the other. It commences its existence being emitted from matter in a particle-like form (a photon), then it transforms into a wave and moves, and then finally it is transformed again into the same particle-like-form (an identical photon to the first) as it is absorbed into matter. Upon which its existence is at an end.

    (BTW, this simple solution to the problem of the dual theories of light is supported, so far, by the double-slit experiment, the photoelectric effect, low-light CCD experiments, and the fuzzy-shadow-edge effect of light.)
    Last edited: Apr 3, 2016
  11. Apr 3, 2016 #10


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  12. Apr 3, 2016 #11


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