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A universe without light

  1. Jul 9, 2008 #1
    (I'm not sure to classify the fallowing as, human error, or just, the way the universe works.)

    What special relativity boils down(something I get from it), is that an observer can only observe something, if and only if, light is reflected off of that something. Example: If I'm traveling at .5c, and my observer was at my starting point, my observer would experience a time delay. Why? Because the faster I travel, the less light reflects off of me.

    Well let's say an object is approaching c. Given the same situation as before, the object's observer would have a time delay of infinity. Why? Because, light will approach the point to where no light at all reflects off the object, hence observing something requires a reflection of light.

    My question is this:
    The theory of special relativity almost seems like its based on the human error, that we cannot, nor any measuring device or observer, can see or measure something without a reflection of light. Furthermore, I don't think that we should build off of it with other theories(gr) and equations(lt), because we're building off of a human error; it may be right to us, it still be useful as classical mechanics is, but it's not an answer to our universe.

    What are your thoughts on this approach?
     
  2. jcsd
  3. Jul 9, 2008 #2

    dst

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    It is not necessarily light but any information. A measurement involves obtaining information with or without light (you could bounce electrons off just as easily or measure changes in a gravitational field). It's just the way the universe works. Faster than light travel is possible in very warped (literally!) scenarios, hit Google with "Alcubierre drive".

    Physics without an observer is string theory.
     
  4. Jul 10, 2008 #3
    True...though I'd say its an interesting theory.
     
  5. Jul 10, 2008 #4
    I'm not saying that there isn't/shouldn't be an observer, I'm saying that the uses of this theory are limited because we can't see an object that has nothing reflecting off of it; It builds off of that principle leading to equations that will adhere to the above principle. I don't want equations that will only be relative to that principle. I want equations that will tell all, not of just what we see, but everything we can't see as well.
     
  6. Jul 10, 2008 #5
    Thus arrive the problems of dark matter (I think).

    Relativity is a used principle and systems like particle accelerators do take into account relativistic speeds (they have systems that help in synchronization to compensate for relativistic effects). The theory also tells that material matter cannot surpass the speed of light...it in fact promotes a large number of concepts that revolutionized physics (that I cannot explain all too well because I haven't really studied in much depth the phenomenon). Relativity is not really just a subject pertaining to how we see things; it in fact does the opposite as well. It states that things do not always occur as we see them or as expected. It is not a theory of everything...if you're looking for that you'll have to wait.
     
    Last edited: Jul 10, 2008
  7. Jul 10, 2008 #6

    Mentz114

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    What about objects that emit light ?

    Generally I don't understand your problem

    What do you mean by 'see' ? As is pointed out in the other posts we have other ways of detecting phenomena so we are not limited to equations just involving light. About things we cannot detect at all, we can say nothing.
     
  8. Jul 10, 2008 #7

    russ_watters

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    I don't se how that is a "human error".
    They aren't. You can use it, for example, to calculate the time dilation of a clock in orbit of earth and you never have to base the calculation on the time delay in sending the signals.
     
  9. Jul 10, 2008 #8

    cristo

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    What problems? Just because you can't see dark matter doesn't mean that you can't interact with it, or that it is not bound by the laws of relativity.
     
  10. Jul 10, 2008 #9
    When a ball hits a blind man in the face, he surely observed the ball, even though light had nothing to do with it.
     
  11. Jul 10, 2008 #10
    Exactly my point, so when an object approaches the speed of light, and we see less and less of it, it almost disappears in our vision, but just because it disappears doesn't mean the object doesn't experience time. The lorentz transformation doesn't really measure what is happening, it measures what is apparently happening.
     
  12. Jul 10, 2008 #11

    Doc Al

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    :confused: Close your eyes and the object "disappears" too. So?
    No it doesn't. It tells you what is happening according to one frame based on measurements made in another. Realize that much of "what is happening" is frame dependent. Nothing really to do with whether you can see it happening or not.
     
  13. Jul 10, 2008 #12
    Yes, the object disapears, but it still is there in space, and is still on the same time line you are.

    If light traveled at infinity, there would be no need for it. The only reason things apparantly change from one frame to the next is because of the reflection of light on the objects(you can see it right in the equations). Like I said before, the equations can be useful to us, but it doesn't make it the answer to the universe. (It's like comparing classical mechanics to quantum. Classical is accurate and useful to us for most things, but quantum is 'more right'.)
     
  14. Jul 10, 2008 #13

    Doc Al

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    I don't know what you mean by "on the same timeline". But if you mean that time runs at the same rate--independent of frame--that's incorrect.
    You seem to think that relativistic effects are somehow an optical illusion due to reflected light. Not so at all. Where did you get this idea?
     
  15. Jul 10, 2008 #14

    HallsofIvy

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    Why would that be true?

     
  16. Jul 10, 2008 #15
    Because if light wasn't reflected off of it, you couldn't see/measure it.
     
  17. Jul 10, 2008 #16
    The Lorentz transformations are real. If the ball is Lorentz contracted to, say, 99%, it'll be that much more likely to miss you. It's not just an optical illusion. It literally occuplies less space from your perspective.
     
  18. Jul 11, 2008 #17
    Using LT, if an object approaches the speed of light, its observer will experience a time delay that's approaching infinity. I think that this approach is wrong. What is really happening is that the object is escaping light; Just because the observer is seeing less and less doesn't mean that the object is not experienceing the same time as the observer is. It just 'Apparantly' seems that way for the observer.

    My best argument has to be that if light traveled at infinity(or if we could see through an absence of light), there would be no need for LT, mass equation, or any equation involving c; This error leads me to believe that there is something wrong with our equations/ideas/theories, at the very least something that we're missing about c.
     
  19. Jul 11, 2008 #18

    Doc Al

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    The "time delay" that an observer would experience for a light signal coming from an object depends on how far away the object is, not the speed of the object. Furthermore, this has nothing to do with the LT.

    Relativistic effects--such as length contraction and time dilation--are not merely "apparent". And they don't depend on any "time delay" of light traveling to an observer. If you want to interpret a raw observation of some distant event that was transmitted to you via light signal--of course you must take into account the light travel time. Relativistic effects are obtained after you make the adjustments for light travel time.
     
  20. Jul 11, 2008 #19
    Well, given the enormous amount of data consistent with SR's predictions, your belief is wrong. Newtonian mechanics is indeed the result of c == infinity, but that doesn't make it right.

    And the object is not "escaping" light. That's a very naive way of looking at it. As I said, if the ball were shrunk by 99%, it'd be more likely to miss you. It has nothing to do with when you see light from the ball. The ball occupies more time and less space from your perspective, i.e. it ages slower and is smaller. You can't explain that just by considering the whole thing an optical illusion.
     
  21. Jul 11, 2008 #20
    Yes, for an observer to observe, light needs to reflect off of an object and travel back to observer which has nothing to do with the object's velocity, but the speed of the reflection and how far away the object at time_reflection is from the observer. (your point?)

    According to my approach, it has everything to do with LT.
     
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