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Curious question

  1. Feb 12, 2012 #1
    I might be in the wrong section for this; however, I have been reading about relativity and I am left with a question. The speed of light is deemed as constant but it is at the limits of our perceptions or senses. Is it not possible, that something in fact can move beyond the speed of light, if it is free of similar trappings that are imposed upon us. For example, if it were possible to remove forces that act upon us locally, such as the gravity of our sun, solar system, nearby stars, even galaxy, would this shift the perception of c?
    Sorry if this is confusing, at the moment its the best way I have of expressing this thought...
  2. jcsd
  3. Feb 12, 2012 #2

    Doc Al

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    Staff: Mentor

    Why do you think this? We can measure the speed of light.
  4. Feb 12, 2012 #3
    Again: welcome to physicsforums! :smile:

    And to elaborate: we can in a lab, point a laser at a mirror and measure the time for the laser pulse to return next to the point of emission. With the old definitions, the speed of light is the total distance divided by the time.

    In that light (pun not intended), perhaps you can re-phrase your question.
  5. Feb 12, 2012 #4
    The speed of light is regarded as, judged as, or considered as constant. Light is part of our perception of everything we can observe. In sight, light is used to see. The speed of light is the fastest known speed, therefore it is at our limits of our perceptions/senses. I never stated that it was beyond our limits. I apologize I thought that part was clearly stated. I will attempt to clarify the rest of the question, which brings context to that statement.

    I am questioning our ability to measure it as constant for the universe and also our ability to measure it as the fastest speed. If we use light to measure it and measure it in the same environment that we exist in, how do we know it this will hold true if it is measured and observed in an environment free of some or most of the limitations that act upon our environment? - This mainly questions constant. Is it possible that something can move faster than the speed of light, but we simply lack the means to observe it at this time? -this is the question related to light being at the limit of our perception senses. For example, how would we measure the speed of light, or even know to, if we did not have eyes?
  6. Feb 12, 2012 #5
    Thank you :)

    I hope my reply to Doc helps.
  7. Feb 12, 2012 #6
    Not really. The measurement that I sketched can be performed in a university room. The point is that we don't need to "run along" with something in order to measure its speed. We can just sit and watch like spectators who watch a car race.
    Another misunderstanding: we simply measure the speed. According to theory, the speed of light corresponds to a constant of nature. The theory has not been disproved.
    In order to measure the speed of a car, one should measure the speed of a car - right?
    That can be done for example by means of interplanetary measurements. According to the general theory of relativity, the speed of light isn't the exactly the same non-locally, just as you seem to suggest. And this was confirmed by measurements.
    We measure the speed of light with light detectors as well as with radio antennas. Light is a form of radio wave.

    Did that help?
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