Photons and lightwaves

  1. I have been wondering, how do photons make up light? Are they particles that travel in transverse waves? Or do they travel in longitudinal waves? Or do they travel in waves at all?
  2. jcsd
  3. adjacent

    adjacent 1,540
    Gold Member

    See this:Is light a wave or a particle?

    Also this: Light.You can see what you are looking for near the end of the article.
  4. Photons are particles of light that have wave like properties, in some ways like the electron. Photons are mass-less particles that have a certain amount of energy (dependent on what frequency of light it is), and can interact via collisions with atoms etc and transfer this energy just like a particle. However, the photons can also diffract around obstacles (only not noticeably for humans as their wavelengths are so small), just like a wave. At first this idea may seem bizarre yet I would suggest taking a look at the photoelectric effect on you tube or asking a teacher to show you as I it answers a lot of questions.
    Hope this helped :)
  5. sorry i meant to say 'i find that this answers a lot of questions'*
  6. Drakkith

    Staff: Mentor

    First, forget everything you've ever heard about photons. It's misleading.

    Consider the view that light is an electromagnetic wave. This view describes 99.9% of all properties you will ever encounter with light, including diffraction, refraction, and reflection. It is only when you look into how light interacts with matter that the "particle" properties come into play.

    It turns out that EM waves only interacts with matter in specific amounts of energy at a time, an amount that depends on the frequency of the wave. The higher the frequency the higher the energy that the wave interacts with. This "packet" of energy is what we call a photon. This is different than the situation in a classical wave, in which energy is transferred continuously, not in packets.

    So no, the photons are not traveling in waves. They are merely the way an EM wave interacts with matter. It is the EM wave itself that is doing all the moving and traveling and oscillating.
  7. Thank you for the answers.
  8. @Drakkith: a very good answer!
  9. sophiecentaur

    sophiecentaur 14,717
    Science Advisor
    Gold Member


    Also, the word 'particle' that is often used to describe a photon is very very misleading to the uninitiated because of all the connotations of that word. You have to make a huge effort and not think of photons as little bullets - especially not 'wiggling bullets'.
  10. Nor electromagnetic field is like this.

    Relativity shows that the division between electric field and magnetic field is artificial. in the 4D formalism appears only an electromagnetic field without division. Electric field and magnetic field depends in the selection of frame of reference.

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