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Impossible? particle, wave, light, radiation,the fundamentals of photons

  1. Apr 23, 2003 #1
    I am trying to get a firm understanding of the fundamental reality of light, radiation, and photons, as modern science presently perceives it all.I am familiar with the two slit experiments and want to know if the particle/wave perception of light makes sense do to these experiments, or if this duel explanation is something which is an impossibility and, therefore, another explanation should be sought.

    1. is it a paradox, and impossibility (by definition a paradox cannot exist) that light can be both a particle and a wave. To answer this I request from those more knowledgeable than I, an explanation of exactly what is meant by light having the properties of a wave. Are these waves thought of as similar to waves that exist within the ocean? Waves in the ocean do not cause water to move ahead. The water crests and troughs but there is no forward movement for the most part (except near land). My desire is to understand exactly what is meant when light is compared to a wave.

    2. Are all forms of radiation thought to be photons in action? X-rays and microwaves are photons distinguishable by the distance between troughs and crests and the height between them?

    If light and all radiation can be compared to both particle and wave does this mean that in the wave activity there is a particle which goes up and down like a wave.Are the particles moving as the ocean moves or are these waves not compareable to such activity.

    Where does frequency fit into the phenomenon of radiation? Frequency is the time it takes for a wave like activity to crest and trough?
  2. jcsd
  3. Apr 23, 2003 #2


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    In reality, there's only one "thing," and it's really neither a wave nor a particle. The subatomic world is very different from the classical macroscopic world. It seems experimentally valid for us to apply a variety of macroscopic qualities (frequency, wavelength, mass, momentum, and so on) to particles, despite the fact that it seems to us that to be a wave and a particle simultaneously is some kind of contradiction. The bottom line is that there's no distinction between wave and particle in the subatomic domain as there is in the macroscopic domain.
    Physically, the only criterion to call something a "wave" is that some quantity varies periodically with time. The electric and magnetic fields oscillate in a photon of EM radiation. The physical similarity between water waves and EM waves, however, is not great.
    The electric and magnetic fields of a photon can be described by a wave equation. That is the only criterion.
    All forms of electromagnetic radiation are simply photons of differing frequencies. You can distinguish them by frequency, wavelength, energy, momentum, etc. Other forms of radiation (alpha and beta radiation, for example) are not photons, but helium nuclei and electrons, respectively.
    Absolutely not. In a photon, it is the fields that are oscillating, not some material "thing" to which you could ascribe a position.
    Frequency * wavelength = velocity. For light, velocity is always (approximately) 300,000 km/s.

    - Warren
  4. Apr 23, 2003 #3
    1) Light is neither a particle or a wave. It's to the best of our knowledge a "quantum field." In essence this means that it's like a wave, but there a sort of "minimum size" of excitation. So if there are only a small number of these excitations (photons) we can usually treat like like independent particles; if there are a lot we can usually treat it like an ordinary wave. In more complicated cases we have to deal directly with the quantum field itself.

    2) x-rays, visible light, radio waves, gamma rays, etc are all the same thing, light. They are distinguished by their frequency -- which is what you said it is.

    3) Nope, photons are NOT like particles moving in a wavelike manner like in the ocean.
  5. Apr 23, 2003 #4
    eh, comeon boys, is there really no better layman description? single weakest photon - wave or bullet? QM field - is it the effect rather than the thing itself? Like sonic boom after a bullet.

    ps. Wave equations are nice. Love wave equations, you could describe **** in the pool with wave equations.
  6. Apr 25, 2003 #5
    The way I understand it, is that the wave form of photons is just the probability that their motion with be in a wave-like pattern. The same was found of electrons released in the dual slit experiment.
  7. Apr 25, 2003 #6
    Probably not - I always found that trying to understand the physics behind photons was difficult if you tried to give a laymans description of it. It just doesn't fit into anything we see in our daily experiences. Same with most of quantum mechanics though really.
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