The Twin (Earth) Paradox

Discussion in 'Physics & Math' started by conscienta, Mar 23, 2012.

  1. OnlyMe Valued Senior Member

    Messages:
    3,914
    Emil, if it is so simple you can do it.

    It is a guess, but I'd say there are 40 to 50 equations in that paper, not including the explanation of terms. Some of it is in the electrodynamics section and.., at least when I was in school was a little above high school math.

    I have trouble getting Tex formatted properly for simple algebra.


    Note: "That paper" was the introduction of SR, not the little book that followed in about 1920 and included an expanded explanation of both SR and GR.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Emil Valued Senior Member

    Messages:
    2,801
    OnlyMe, that is why I wanted to see from where you've got the math required for SR.
    Then I will put the mathematics that I consider proper.
    Is needed notion of distance, time and speed (not velocity).
    I guess I was wrong, saying the high school level. I think the level of school is enough.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. OnlyMe Valued Senior Member

    Messages:
    3,914
    Emil, I believe we have gone round on this in the past. I could be mistaken, when I was younger I remembered just about everything, I sometimes have to stop and think what I had for breakfast now, and I just finished.

    If you have any point to make, make it. Anyone who disagrees can then respond as they wish. If you know what the math that SR is based on is, you could present that yourself and then point out the errors you believe there are.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Emil Valued Senior Member

    Messages:
    2,801
    OnlyMe, if you noticed, I intervened when someone send someone else to learn or read SR.
    If you have the proper math, it is so simple that there is nothing that you can not understand.
    And I have stated many times, the mathematical deduction for SR is correct.
    Also from mathematical deduction, you can see clearly where intervenes the invariance of speed of light.
    In a medium where the invariance of speed of light is not satisfied, there is no SR. This results directly from mathematics.
     
  8. OnlyMe Valued Senior Member

    Messages:
    3,914


    This, the statement in red, is something you would have to prove. I do not know how you arrive at that assumption. It does not seem to be consistent, with anything previously discussed, at least in this thread, that I remember.

    If what you are tring to say is that for a diver submerged in water, things do not always appear the same as they would in air of vacuum, you are correct. But you do realize that for aquatic animals, even mammals the same is not true. Their eyes are adapted for the way light is affected by water as a medium. Some are even able to adjust to accurately see in water or air.
     
  9. Syne Sine qua non Valued Senior Member

    Messages:
    3,515
    Accounting for the refractive index, SR it valid for light in a medium.
     
  10. AlphaNumeric Fully ionized Registered Senior Member

    Messages:
    6,702
    The invariance of the speed of light refers to in a vacuum. There is still special relativity in mediums, you just have to include particle interactions between the medium and the light. For example, Chernkov radiation is the result of charged particles, like electrons, moving through water faster than light moves through water. You can correctly describe the phenomenon if you use quantum field theory, which is built upon the combination of quantum mechanics and special relativity. When you model the interaction of the photon field with the electron field and molecules of water you find the net effect is the photons have a group velocity slower than usual which interacts with the electrons in a particular manner, emitting the bluish glow associated with the effect. So there most definitely is special relativity in such systems, it's just it's not special relativity of an empty vacuum.
     
  11. Emil Valued Senior Member

    Messages:
    2,801
    I seriously think if you understand the mathematical demonstration. Where intervene the invariance of speed of light and the condition that nothing can exceed the speed of light, in that system.
    Translated into practice the invariance of light speed briefly is the following:
    Two objects that have between them a relative speed V.
    Invariance of speed of light : speed of light relative to the object 1 is c, the speed of light relative to object 2 is c.
    No invariance of speed of light:speed of light relative to the object 1 is c, the speed of light relative to object 2 is c-V.
    So it depends on what speed is between the object and light.
    If in the mathematics, you do not take into account the invariance of speed of light, just not result SR. It's simple.

    Try for the sound.
    Assume that the sound speed is constant, relative to any moving object, and will result SR.
    Huh?
     
  12. Emil Valued Senior Member

    Messages:
    2,801
    Only if you assume the invariance of speed of light is true in that medium.
     
  13. Emil Valued Senior Member

    Messages:
    2,801
    Huh?
    I rely only on the mathematical demonstration. That is enough !
     
  14. OnlyMe Valued Senior Member

    Messages:
    3,914
    Alpha did a far better job of explaining the issue.

    I almost always try to imagine how could someone be thinking what the do. The translation issue likely adds to the problem.

    However, you are right! "Huh?" would have been a better response than the one I gave.
     
  15. OnlyMe Valued Senior Member

    Messages:
    3,914
    Emil, Alpha has at least a Masters degree in mathematics and a Masters or Phd in physics. If he did not post as he did in terms I could understand and presented it all in math, it is likely we would both be saying, Huh?
     
  16. Emil Valued Senior Member

    Messages:
    2,801
    It was not an explanation. It was a evasion.
    That means you affirm I should shut up, if I prove not that who I am?
    Don't you find arrogant this position?

    From my experience I say, those who really know are not arrogants, because they realize how little they know.
     
  17. OnlyMe Valued Senior Member

    Messages:
    3,914
    I never said anything close to shut up. I have never said anything like that to you that I remember.

    What I said was actually an acknowledgement that Alpha could put it all into a frame work of mathematics that would make my head hurt.

    I used to literally be able to see the geometry, now I have to look things up to know what is actually being discussed, when all that is being presented is the math without description and definition of terms. Even then most of the time I no long "see" it. It is more like a translation.

    Why don't you just post what it is you are thinking, including the math. From there anyone interested can comment.
     
  18. Tach Banned Banned

    Messages:
    5,265
    You sure about that? Because you are dead wrong.Did you go to the "MotorDaddy school of relativity denial"?
     
  19. origin Heading towards oblivion Valued Senior Member

    Messages:
    11,890
    He was a star pupil.
     
  20. Emil Valued Senior Member

    Messages:
    2,801
    This seems to me the most efficient explanation I ever heard.

    Special Relativistic time dilation and length contraction derived

     
  21. Emil Valued Senior Member

    Messages:
    2,801
    Last edited: Apr 3, 2012
  22. origin Heading towards oblivion Valued Senior Member

    Messages:
    11,890
  23. AlexG Like nailing Jello to a tree Valued Senior Member

    Messages:
    4,304
    Emil is just giving a synoposis of his arguments.
     

Share This Page