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Is the Universe Galilean?

  1. Jan 17, 2010 #1
  2. jcsd
  3. Jan 17, 2010 #2

    bcrowell

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    I took the time to download and view the Word file, but you will probably get more responses if you post the text directly. The equations in the Word file didn't come through for me; this is another reason why it would be better to post here. (You can use latex math inside special tags, e.g., I can do [itex]E=mc^2[/itex]. To see how this is done, click on the Quote button for this post, and it will show you the way I entered the equation.) In general, it's not safe to assume that everyone on the internet uses the same word processor you do.

    I wasn't able to figure out what your post was really trying to say, based on a quick reading. You might want to make clear whether your idea predicts different results for experiments than SR does, or whether it's just meant to be a derivation of SR from an unusual perspective.
     
  4. Jan 17, 2010 #3

    D H

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    That was bold (or maybe foolish) of you! I would be reluctant to open a Word file posted by PF member that I respected & trusted, let alone a newbie with 12 posts to their name.

    =============

    gamburch:

    If you want to get any mileage out of this thread, you would best serve yourself by posting the words and equations directly -- or at least enough of the words and equations to grab our interest.

    This is of course assuming the thread isn't closed for violating PF rules re no personal theories. Are you following the rules? Did you even read the rules when you signed up at this site?
     
  5. Jan 17, 2010 #4
    Your document is to long for my interest. Can you tell me the basic idea here?
     
  6. Jan 22, 2010 #5
    Yes you are wrong for a very simple reason. Special Relativity as it is almost universally understood created the whole idea of spaces, times, distances and speeds that deviate from the Galilean standard ideas by virtue of use of the Lorentz Transformations in their simplest form. In some of your arguments and some of your math you have drifted into conventions that didn't exist for special relativity which began from a Galilean framework that was modified by the effects of the Lorentz Transformations. Your "four space" with invariant time is an oximoron within either SR or GR. SR demands variable time in some instances when Lorentz equations are used and the four dementional space-time continuum is a product of GR. Your "four space" is a non-idea that doesn't exist in any known system.
     
  7. Jan 22, 2010 #6

    Mentz114

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    Gibberish. Goodbye.
     
  8. Jan 23, 2010 #7
    No. "Galilean" implies one, single flow of time for all observers. At the very least, the universe is Special Relativistic.
     
  9. Jan 24, 2010 #8
    DanRay:

    Thanks for the time you spent writing a reply. My post agrees with you that Special Relativity (SR) is not Galiliean as normally defined. Where we differ, I believe, is that you accept SR as true. I believe I note that many will feel this way. What I seek is to answer the question as to why it is not. To assume that I have to be wrong because Special Relativity us right is not the answer I had hoped for.
     
  10. Jan 24, 2010 #9
    GRDixon:

    Thanks for the reply. Doesn't it bother you that Special Relativity (SR) has observers, moving with respect to each other, exist in different Universes? In my note I make up a space with four-space coordinates and a universal time coordinate. This is not the space of SR nor is it the space contemplated prior to SR.

    The question I'm asking is what is it about observers that make us see SR. The answer I argue is that all observers move at the speed of light in different directions in the underlying four-space and observe each other with signals that move at the speed of light in this same space. I tried to show that this model leads to each observer seeng th space of SR.

    What I now am asking everyone is whether this make any sense to anyone other than me.
     
  11. Jan 24, 2010 #10
    edpell:

    You might take a look at the reply to GRDixon.
     
  12. Jan 24, 2010 #11
    bcrowell:

    I have to travel this next week, but will try to get the posting more up front. To answer your question, my posting is about giving an explanation for Special Relativity. To the depth persued in the note, I can't see that it makes any new predictions.
     
  13. Jan 24, 2010 #12
    I find the idea of a universal time very appealing. Feynman talked about what if there are two time coordinates. I have wonder if he was thinking of SR. What do you mean you have four space coordinates? What does each represent?
     
  14. Jan 24, 2010 #13
    I like this idea that everything moves at the speed of light always. Is one of the four-space dimensions time?
     
  15. Jan 24, 2010 #14

    sylas

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    Gentle colleagues; it may be a good time to recall physicsforums guidelines.

    There may be other forums on the web that are better suited to looking at ways to reinvent physics. Here, if you cannot give a credible reference showing that your proposals are already a part of current mainstream discussion, then it's not something up for discussion.

    Cheers -- sylas
     
  16. Jan 25, 2010 #15
    Sylas, OK here is a quote from full tenured professor of Physics Columbia University Brian Greene's book "The Elegant Universe" page 50, "Here's the leap: Einstein proclaimed that all objects in the universe are always traveling through spacetime at one fixed speed--that of light." This is accepted canon.
     
  17. Jan 25, 2010 #16
    How about we add a forum title "talk about new ideas in physics" that people who want to talk about new ideas can use and leave everyone else in peace?
     
  18. Jan 25, 2010 #17

    George Jones

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    The concept that Greene stated imprecisely is that the magnitude of any (inertial, accelerated, SR, GR, etc.) observer's 4-velocity [itex]\mathbf{u}[/itex] is [itex]c[/itex], i.e.,

    [tex]c^2 = \mathbf{g} \left( \mathbf{u} , \mathbf{u} \right) = u^\alpha u_\alpha .[/tex]

    The 4-velocity [itex]\mathbf{u}[/itex] is a timelike 4-vector, and thus always has a non-zero time component.
     
  19. Jan 25, 2010 #18
    As to absolute time I would say this is a false issue. Just pick an IRF and use the clock in that frame as your "universal time". Yes, all IRF are equally good and in fact they all work. Using SR we can translate the clock time in our chosen IRF to the time on a clock in any other IRF. And likewise using SR we can translate the time on a clock in any IRF to the time on the clock in our chosen IRF. Every clock in an IRF is a "universal clock".
     
    Last edited: Jan 25, 2010
  20. Jan 25, 2010 #19
    He goes on to say----We are presently talking about an object's speed through all four dimensions, three space and one time, and it is this object's speed in the genealized sense that is equal to that of light-------

    Matheinste.
     
  21. Jan 31, 2010 #20
    edpell:

    If one has a wave equation in a space with four spatial coordinates and a universal time, one can imagine a wave equation in that space. If an observer is moving at the speed of that wave in a given direction in that space then, for him, time equals the coordinate in his direction of travel (x = ct). Thus to answer your question, the observer in question is traveling along the fourth coordiante, but cannot see it because of his motion and because he must use light for signaling. The same is true for all observers. Though all observers see the same universe in their own frame of reference, this frame is different for any two observers traveling in different directions. In that case each sees the other as moving as seen from his own frame.

    With respect to sylas, I cannot help but thinking that this is just a little fun about an interesting idea. I understand that original work should, perhaps, be peer reviewed, but in a forum, if cannot one throw somethig against the wall, where can one?
     
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