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Types of experiments conducted to detect the speed of light After M&M

  1. Oct 25, 2013 #1
    I have red only about a few experiments conducted to detect the speed of light using interference pattern.
    but i need to know whether there have been any experiment conducted by MOVING LIGHT SPEED DETECTOR (INTERFERENCE DEVICE) & keeping the source of light and mirrors in rest?
    If there haven't been any attempt, then why?
     
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  3. Oct 25, 2013 #2

    ghwellsjr

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    I'm not sure what you have in mind. Can you be more precise? Are you wanting a moving detector to be colocated with the source of light at the moment of emission and then to be located somewhere else when the reflection was detected? If so, what distances would you use for the two paths of the light? The rest frame of the source and the mirror or the rest frame of the detector? Or do you have something else in mind? And why do you think an experiment like this would be important? What are you concerned about?
     
  4. Oct 25, 2013 #3

    jtbell

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    At rest with respect to what?
     
  5. Oct 25, 2013 #4
    keeping the source of light and mirrior (if needed) in rest with respect to the lab/scientists
    I want the detector to move and check the speed of light
     
  6. Oct 25, 2013 #5

    ZapperZ

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    Is there a reason why this would make a difference? Is there an impetus for you think there is a possibility of such an asymmetry i.e. why are you expecting this will not be the same as moving source with stationary detector?

    Zz.
     
  7. Oct 25, 2013 #6

    ghwellsjr

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    What do you mean, "if needed"? You're the one who is asking the questions. We can't answer unless you tell us what you mean. Please answer all of my questions or at least narrow down what you have in mind.

    You already said you want the detector to move but you haven't described how in relation to the source of light and the mirror you want it to be moving and now you're not sure about the mirror. If you were a lab professor and you gave this requirement to your students, how many different experiments with different results do you think they would come up with? Do you think any of them would come up with the one you have in mind? Please provide all the details so that you could grade the students on how well they followed your instructions and then maybe we can address your concern. Or you could just tell us what your concern is like I already asked you.
     
  8. Oct 25, 2013 #7
    First, could we establish is you are interested in measuring the one way speed of light or the the two way speed? This might determine if the mirror is required or not.
     
  9. Oct 26, 2013 #8

    Dale

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  10. Oct 26, 2013 #9
    Well yesterday i didn't have enough internet connection, I'm sorry
    What i asked was that
    Consider an experiment which consists a source of light (laser) and a Light speed detector. Both are kept in a straight line.
    The experiment follows like, i move the detector with a velocity of 100m/s from the source. Then i fire a laser to the detector, so will there be any change (decrease) in the velocity of speed of light?
    I know there won't be, but WHAT I NEED TO KNOW IS, have there been any similar experiments?
     
  11. Oct 26, 2013 #10

    ghwellsjr

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  12. Oct 26, 2013 #11

    ghwellsjr

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    What do consider to be a light speed detector? Does it have to involve interferometry like you twice stated in your first post?
     
  13. Oct 26, 2013 #12

    ZapperZ

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    You didn't answer my question. Why do you need this?

    There has to be some theoretical impetus to test something. One can't just say "Oh, let's do this. I have no good reason why. It's just for the heck of it." That is why I asked why you'd expect there is an asymmetry between "source moving, detector stationary" versus "source stationary, detector moving".

    No one is going to test something for no rational reason. We continue to test on any possible mass of photons not because we don't accept that photons have no mass, but because there are new theories that haven't been verified yet, and they include possibilities of such a thing. So there is a theoretical impetus to want to make such a measurement. I don't see one for the type of experiment you're asking for. So is there a rational reason for you wanting to know if such experiments have been done?

    Zz.
     
  14. Oct 26, 2013 #13

    Dale

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    Please read through the list of experiments I posted to see if there are any you consider similar enough. Please keep in mind that there is no difference between a moving detector and a moving source.
     
  15. Oct 26, 2013 #14

    Dale

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    The problem is that the M&M experiment didn't measure the speed of light. In that sense, the OP is self contradictory.
     
  16. Oct 26, 2013 #15

    ghwellsjr

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    I think the problem is that the OP won't tell us what he means by a "light speed detector" that has no mirrors, yet is an "interference device", nor will he answer any of the other numerous questions that at least four different people have asked him.
     
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