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Properties of a Photon

  1. Feb 11, 2009 #1
    A source of light is generating photons outwards from itself in all directions. At some point, wouldn't the photons become spaced apart enough to create gaps (I'm thinking of a bicycle rim where the spokes represent the photons moving away from the center of the rim representing the light source)? At which point, 2 observers, equal distance from the light source but at different angles, would not see the same light source?

    I understand that I'm comparing a beam of light using an example of an object with mass, but I can't think of a better way to explain it.
  2. jcsd
  3. Feb 11, 2009 #2
    You are forgetting that when you physically see something there is a time element too. For example when you see a bolt of lightning the amount of time that your eye registers it is actually much longer than the bolt is actually there. The cells in your eye get excited and send off a signal which your brain interprets. If you had an accurate enough observing device it could note whenever a photon struck it from any particular source. In reality as you get further and further away from an object it will seem to grow dimmer and dimmer, as your eye intercepts fewer and fewer photons. After a certain distance it would fade into the background. Your eye is not sensitive enough to pick out one photon of light. When it comes to electronic gizmos I believe there are some that you can tune down to that point. But then the uncertainty of where a particular photon came from may be problematic.
  4. Feb 11, 2009 #3
    Sure. Photons are very small. Less then a µm.
    So if you stand far enough away from a light source there would be spaces in between the photons.
    Let's say there was a light bulb on the moon and you look at it through a telescope.
    You might not even see the light bulb because only a few photons per second hit your telescope.
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