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The essence of light.

  1. Jun 6, 2008 #1
    Can somebody tell me when was it decided that light was made of "matter"? I am supposing this assumption based on the concept of "black holes" being capable to "attract" light itself back to its core. I think we do not "see" light from blackholes because wavelenght is shifted to a non-visible frequency due to strong electro/magnetic field within the black hole. So, it is not "attraped" but rather "converted". If light was capable to be "attracted" by black holes, then we would be virtually "blind" from our universe. Imagine the hundreds/thousands of blackholes that beams of distant light would have to pass near by without being "attraped" or at least "deviated". So, we would be able to "see" a totally different universe from what actually "looks like".

  2. jcsd
  3. Jun 6, 2008 #2
    Light is not made of "matter."
    Anything massive attracts light, especially "blackholes" (being especially massive).
    We do see light from black holes, just not from the inside.
    E&M fields inside the black-hole have no effect on anything outside of the blackhole (at least the vast majority of the time).
    Most astrophysical observation is not done in the visible spectrum; light being shifted into a non-visible range is not an issue when using "technology."
    "Attraped" is not a word.
    Blackholes occupy a very small fraction of the universe and do not constitute a large impediment for most observations.
    All light is "deviated," continuously... we still manage to "see," although some species of mole are "blind."

  4. Jun 6, 2008 #3
    Light is made of Photons. The photon is an elementary particle, but not technically matter because it does not have mass. I have no idea who or when that was "decided".

    I'm not an expert, but I'm pretty sure that is completely wrong. :smile: The concept of a blackhole came from General Relativity.

    Light is trapped by black holes, as is anything within it's event horizon. Light outside of this EH would be affected, but not in the manner you describe. Gravitational lensing is in fact used in astronomy.
  5. Jun 7, 2008 #4
    I still have my question unanswered, how can black holes trap light if it is not a particle? My hypothetical answer is that it does not trap it, it just changes its properties to be a non visible wave. By the way, thanks for the link.

  6. Jun 7, 2008 #5


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    A black hole warps space time so much that light can't escape. One must move away from the thought of gravity being a force acting on a particle with mass to gravity bending space itself when considering these things. I think its more a matter of semantics. Look up the definition of matter and see whether it fits.
  7. Jun 7, 2008 #6
    See this: https://www.physicsforums.com/archive/index.php/t-70266.html

    Nothing escapes a black hole, not even light. So in a sense it is trapped within the black hole. See event horizon. What happens to the light or anything else after it has passed the event horizon is still under controversy. It is theorized that information of what has fallen into a black hole may be re-emitted as radiation later. See hawking radiation and black hole information paradox.
    Last edited: Jun 7, 2008
  8. Jun 19, 2008 #7
    Light while it is not matter,and has no mass it is pure energy in the form of photons . Light is, however,is "something" and a black hole will suck up "anything" that comes too near it, including light


  9. Jun 19, 2008 #8
    funny when i say things like this people tear my wording apart so bad... light does not have resting mass but it does have mass... define "pure" energy...
  10. Jun 19, 2008 #9
    The earliest referenced of such a comment was made by Einstein in 1916 in his paper On the Foundations of the General Theory of Relativity where he wrote
    Before you can state what is or is not matter you first have to define it. So please state the definition of "matter" in the sense that you are using it. Perhaps you can also tell us why you prefer to define it in that way? Thanks.

    See above comment and please define what you mean by pure energy please. Thanks.

    Last edited: Jun 19, 2008
  11. Jun 19, 2008 #10
    Why "must" we?

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