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The universe through the eyes of a photon

  1. Jun 22, 2004 #1
    Wouldn't it be weird to see the universe as a photon sees it? I mean, assuming that photons think they're traveling in a straight line(of course photons don't think!) and traveling at c the whole time, the world would look really strange. Pools would be alot deeper, mirrors would be warped to no end, and then finally, my eyeball.

    Pretty neat to think about.
  2. jcsd
  3. Jun 22, 2004 #2
    Photons don't experience time so well.

  4. Jun 22, 2004 #3


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    You'd see the beginning.. and the end. All at the same time. (Division by zero, aah..)
  5. Jun 22, 2004 #4
    Well, i for one would want to pave a better road because this one's too bumpy. '.'.'.'.'.'.'.'.'.'.'.'.'.' ahhhhh
  6. Jun 23, 2004 #5
    Well okay ignoring relativity. :/ should have put that in my original post.
  7. Jun 24, 2004 #6


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    You can't really ignore relativity while travelling the speed of light. :smile:
  8. Jun 26, 2004 #7
    if i am a photon i will wonder upon this fact.

    since i travel in the speed of light the time for me would be zero.
    but i am at a constant velocity of 3*10^8 m/s

    Now if i travel 100 m and i try to calculate my speed
    my distance(s) = 100m
    my time(t) = 0 sec
    so now my speed would be 100/0
    so the solution to my problem is infinity.
    Now Mr Einstine tell that my speed is 3*10^8
    how is it possible?
    is 3*10^8 =100/0 ??????????????
  9. Jun 26, 2004 #8
    But the time to travel 100m would NOT be 0. It would be very very very small but NOT 0.

    If it took 0 seconds to travel 100m.
    It would take 0(infinity) to travel 100(infinity).
    If your argument was true then they would not travel at the speed of light, they would travel everywhere INSTANTLY.
    Evidently this is not possible.
  10. Jun 26, 2004 #9
    The time to travel 100m for u as a viewer is very small but i as a photon have no time (since einstin proved that time stops for a person travelling at the speed of light )
    as a matter of fact ur statment that photons travel INSTANTLY is true from the photon's point of view
  11. Jun 26, 2004 #10
    But you're arguing the fact that time is distorted for that particular particle. When time has been distorted surely we need to devise a new set of rules by which to apply distance and time.
    Surely it's still 'taken time', even if the effects of time have been distorted.
    If you were to apply your rule, the photon would travel across the universe instantly, hense meaning the photon would be 'everywhere' at the same time, and would thus occupy the entire universe.
    Surely this cannot be true.
  12. Jun 26, 2004 #11
    ..'everywhere in its path at the same time' maybe, but not 'everywhere in the Universe'

    This is indeed correct. It is an odd concept, but when you look at the Andromeda Galaxy with your naked eye, the photons that interact with your retina were emitted in that Galaxy at exactly the same time that they strike your eye, even though to us, it took them two million years to get here.

    Physics is very odd sometimes.. (as far as the human brain is concerned anyway!) :yuck:
  13. Jun 27, 2004 #12
    you're mixing up the viewpoints though. for us it seems to have taken time for it to travel. but like Adrian said.. from the photon's perspective, the time it was emitted was the same time it was absorbed. time is distored for the photon compared to the still observer, giving 2 different lengths of time.
  14. Jun 27, 2004 #13
    I would also wonder upon this fact. If i am a photon and there also exist a photon brother of mine traveling in an opposite to me with the save speed ie 3*10^8. Why dont we crash ?
    Why am i unable to interact with him?
  15. Jun 27, 2004 #14
    I got a feeling that a lot of people in here are mixing up special relativity and classical mechanics.
    cookiemonster was right in saying that photons don't experience time that well. They would not be seeing the start and the end at the same time and everything would crash up, however, as Alkatran suggested. I think they'd see the world around them moving at the speed of light in the opposite direction, in still motion, until the photons themselves crashed into something.
    benzun_1999 mixed up the reference frames. If you observe the photon moving at the speed of light, then you would be on any other reference frame, other than the photon itself. Your time wouldn't be zero, because you're not the photon who is travelling at the speed of light, with reference to you.
    KnowledgeIsPower was also wrong. You can't mix up two reference frames. You observe yourself as if you were standing still...I mean, would you ever say that you see the car with a velocity with respect to you when you are in the car itself? So, you aren't travelling at all.
    I'm not sure what benzun_1999 meant in his last post o_O...
  16. Jun 27, 2004 #15
    Maybe i am mixing up the refrence frames but yes i agree with u that i should'nt have tried to calculate the speed of a photon like that.
    But as a photon how would you calculate my speed ?
    and in the second post i man that to photons traveling opposite to each oter don't interact. Why?
  17. Jun 27, 2004 #16
    in reply to benzun_1999:

    well correct me if my limited understanding is wrong but for a simple explanation..
    because the photon is moving at 'c', all it's energy is place into moving it through space so there's nothing left to move it through time. therefor time does not pass from a photon's reference frame.

    since there is no passage of time, from the photon's perspective you can't calculate average speed the same way we do in our daily lives. v=d/t. it's a meaningless formula for instantaneous or light speed. from it's point of view time is basically meaningless?

    again correct me if i'm wrong. i'm still learning and don't mean to thrown anyone off with false info if i am incorrect in my simplified explanation. :smile:
  18. Jun 27, 2004 #17

    Wrong. For the photon the travel is instant. However, this is possible because in Minkowski space-time points with a zero spacetime interval between them are light-speed apart, or more simply, the length contraction of the world around the photon as observed by the photon at light-speed compresses all of space in the direction of travel to a single point, it does not cover any distance as it sees it.
  19. Jun 28, 2004 #18
    If a photon doesn't expierience time, then doesn't that mean that the photon only exists in three dimensions?
  20. Jun 29, 2004 #19
    no. it's there. it just doesn't perceive it.
  21. Jun 29, 2004 #20
    I thought that the definition of a dimension was a description of the environment that something exists in? If a photon exists in an environment with time not as a factor, then doesn't that mean it only exists in 3d space? Or anoter question..Can something that only exists in 3d space reside in 4d space?
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