Education and Crank Claims: Special Relativity

Discussion in 'Physics & Math' started by rpenner, Oct 5, 2011.

  1. OnlyMe Valued Senior Member

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    I have not thought your posts as of yet were in the crank category.

    ------------​

    MD on the other hand has had his "unique" perspective addressed in at least two previous threads and it should not be given further legs here. He is not interested in discussing SR, as much as he is interested in making contrary and unsupported claims.

    The OP established this as a discussion of SR, not MD's personal ideas.
     
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  3. OnlyMe Valued Senior Member

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    While true, the first sentence in the OP,
    Is a bit more restricting.
     
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  5. Motor Daddy Valued Senior Member

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    Well considering you consider me a crank, I have made claims, now address them.

    It's just like you to believe what you want to believe. You read what you want the words to read, not what they read.
     
    Last edited: Oct 5, 2011
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  7. AlphaNumeric Fully ionized Registered Senior Member

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    All you've done is assert things. You claim things because that's what you think but you haven't demonstrated that's how the universe works.

    SR's description of light spheres in different frames is self consistent. To claim otherwise is to simply be wrong. If you want to claim SR isn't how reality works then fine but that's a matter of actual experiments, not a thought experiment.

    Nice hypocrisy. You demanded I provide mathematics to justify my claims and refutation of your box scenario and when I did you never responded to the maths. You're all talk and when someone steps up you're suddenly not replying.
     
  8. wlminex Banned Banned

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    . . .revist "rainbows"!
     
  9. Motor Daddy Valued Senior Member

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    You seem to fail to grasp the importance and concept of what I "claim." What I am "claiming" is that according to our definitions of distance and time, there can only be the way I describe it. Anything else is flat out wrong. Oh, SR may be mathematically self consistent, but clearly we know the math can be right and the concept flawed, don't we, AN? There need not be an experiment to justify my "claim." What I "claim" is the very nature of the concept of our language of distance and time, as it is defined. Change the definitions if you don't like it because it doesn't match your "preferred theory." But until you change definitions, SR is flat out wrong. Put another band-aid on it. Stick a fork in it, it's done!

    You never refuted the box. You simply showed the math to how a light sphere can be a light sphere to two different frames, which is flat out wrong according to my "claims" as to how distance and time are understood to be defined.
     
  10. billvon Valued Senior Member

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    No. According to YOUR definitions of distance and time, there is only one way you can describe it. Using our standard definitions of space and time there are others.

    But actual experiments, conducted in the real world, prove your interpretation wrong.

    That's the same as refuting the box. You presented the box (with your math), he demonstrated why your math was wrong.

    But if you prefer a graphical representation, here it is:

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    In this image, the red dot and the blue dot are two observers, one moving at about half the speed of light relative to the other. Notice they both are in the CENTER of the light pulse from their own perspective.
     
  11. Emil Valued Senior Member

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    2,801
    Crank .... is relative.
    There are only two camps.
    Camp1 says: The Lorentz transformation must be applied to camp2.
    Camp2 says: No, Lorentz transformation must be applied to camp1.

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  12. DonQuixote Registered Senior Member

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    Accepting it in the first place should not be required. We should carefully examine what it says, and be sure we have understood it.Then, if we reject it, we should be able to say why.
     
  13. Motor Daddy Valued Senior Member

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    No he did NOT demonstrate that my math was wrong. Where do you get this stuff?

    I showed that it takes .65 seconds for the light to reach the z receiver, which is only .5 light seconds away from the source in the cube frame.

    How about you tell me how you measure light to be c in the cube frame, when it takes .65 seconds for the light sphere to reach the z receiver??

    According to my calculations, in the cube frame, the speed of light is measured to be .5/.65=.769 c from the center of the cube (the source) to the z receiver.

    According to my calculations, in the cube frame, the speed of light is measured to be .5/1.384930=.361 c from the center of the cube (the source) to the x receiver.
     
  14. AlphaNumeric Fully ionized Registered Senior Member

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    6,702
    I've already explained to you you are mistaken. You seem to think if an object is 1 light second in size in one frame then it is 1 light second in size in all frames. That isn't what relativity says.

    We're used to saying "The rod is 1 metre long" because in our everyday experience objects moving are the same length as if it were at rest but that's only because we can't notice the difference. If we were being totally accurate we should stipulate what frame the length is measured in. A rod 1 light second long in its rest frame will not be 1 light second long in a frame moving relative to the rod's rest frame.

    Definitions of length in terms of light have no relevance to this. If someone uses a laser and a stop watch to build the rod 1 metre in length in its rest frame that doesn't mean in another frame it'll be 1 metre in length, even though both frames measure the speed of the laser to be c. Instead the moving frame will say "The rod is shorter! It takes light less than 1/c seconds to traverse the length!".

    I have previously addressed your comments about definitions. And my mathematics was more than just showing light spheres map to light spheres. Didn't you understand it? Would you like me to go over it again?
     
  15. Motor Daddy Valued Senior Member

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    5,425
    There is only a cube in my example. In the cube frame it takes light .65 seconds to reach the z receiver, and 1.384930 seconds to reach the x receiver. In the cube frame, the source is at the center of the cube, and the receivers are an equal distance away from the source at the center of the cube, verified by an equal rod count from source to receivers. So in the cube frame, the distance is equal from source to receivers. But it takes .65 seconds for light to reach the z receiver and 1.384930 seconds to reach the x receiver in the cube frame.

    So are you saying light travels at different speeds in the cube, depending on which way you measure it?
     
  16. billvon Valued Senior Member

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    From his post.

    In your frame, correct. In the moving frame, incorrect.

    Because in the cube frame the observer is experiencing time pass at a slower rate. Thus he measures what you think is .65 seconds, looks at his accurate clock (100% accurate in HIS reference frame) and says "look at that, it took .5 seconds for the light to reach the Z receiver. The speed of light is still C."

    Yes. Your calculations are incorrect.

    Imagine you are trying to teach someone vector math. He's having a little trouble.

    ========================
    Teacher: So if you add a vector of length 1 along the X axis, and another vector of length 1 along the Y axis, how far are you from the origin?

    Slow student: 2! Because 1+1=2.

    T: It might seem that way. But look here. The end of this vector is at X=1, Y=0 on the cartesian plane. Add a vector here and the end of the NEW vector is at X=1, Y=1.

    S: Yes! 1+1=2!

    T: Well, no. Because the distance from the origin to the end of the new vector is not 2, it's the hypotenuse of this triangle, and that's 1.414. See, if you measure it . . .

    S: What, are you stupid or something? By my calculations 1+1=2. My math is correct. I can PROVE it.

    T: That's only if you lay them end to end in the same direction. If they're not in the same direction, they don't add like that. You have to take the distance of the . . .

    S: 1+1=2!

    T: Again, you're missing the point. We're talking about two coordinate axes here, not one. You can't just add them and get . . .

    S: 1+1=2!
    ==============================

    Is the student correct?
     
  17. origin Heading towards oblivion Valued Senior Member

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    Why in the name of god are you letting MD derail an interesting topic.

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    Ignore him. Does anyone honestly think there is any hope of rational discussion with him?!
     
  18. Motor Daddy Valued Senior Member

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    In the cube frame, the source is at the center of the cube, and the receivers are an equal distance from the source. It takes light .65 second to reach the z receiver and 1.384930 seconds to reach the x receiver. That is the times it takes light to reach the receivers. Do you comprehend that?

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  19. OnlyMe Valued Senior Member

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    The statement above is accurate.

    It does not seem to apply to MD. As you can see what began as potentially a very good thread to discuss SR, has already begun to degrade into a copy of at least two previous threads debating MD's own ideas of space and perception.
     
  20. Motor Daddy Valued Senior Member

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    Really? So the observer knows the distance from source to z receiver is the same as the distance from source to x receiver, understands that light speed is constant, but he can't understand why it takes a different amount of time for light to reach the z receiver than the x receiver. Do you understand English?
     
  21. DonQuixote Registered Senior Member

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    Thank you, that's encouraging. My next question is going to have something to do with the phrase "as viewed from".

    I have yet to find a qoute from E to make this question precise, but It's likely to involve train cars, I think.

    It's been a long time since i looked closely at "on the electrodynamics ..." but a quick scan tells me there's not a lot of train cars in it. E wrote book much later, where he explains the special theory by way or train cars. I borrowed it in norwegian translation from the library a few months ago, but had to return it.

    It has something to do with wheter the changes of length and time "as viewed from" some (presumed stationary) reference frame is simply due to the time the light signal takes, or if it is concidered a real change in the moving frame, or if "as viewed from" means something else.

    I apologise for not being able to frame the question more presicely right now. I'll come back to it.
     
  22. billvon Valued Senior Member

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    21,634
    Answer the question posed in my example first and I'll answer yours. Is the student correct?
     
  23. billvon Valued Senior Member

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    21,634
    He does understand it, since it takes the same amount of time for light to reach the Z receiver.

    I do understand English. You apparently do not understand physics.
     

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