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Humans have true 4D spatial vision

  1. May 28, 2005 #1
    Humans have full 4D spatial vision

    Consider this:
    1) objects in motion show non-simultaneities along the direction of motion (the "temporal distance" between the endpoints is [tex]\gamma vl/c^2[/tex])
    2) objects in motion show time dilation (the "temporal velocity" runs slow with a factor [tex]1/\gamma[/tex])

    If our spatial vision would have been truly 3D:
    1) implies that we would only see(*) a single point of the object with precisely the time-coordinate that coincides with ours.
    2) implies that moving objects would vanish in the past alltogether.

    Those things obviously don't happen so we have full 4D spatial vision, i.e. we can observe all 4 dimensions in its entirety.

    (*) With "see" in this context I mean the usual "instant observation" of events as often used in relativistic thought experiments.
     
    Last edited: May 28, 2005
  2. jcsd
  3. Jun 1, 2005 #2
    Can you see things that do not have the same time-cordinates as yourself in your own frame of reference (not taking into account the time it takes time to travel from them to you)?
     
  4. Jun 1, 2005 #3
    Yes you can. Its even so that every moving thing around you has different time coordinates compared to yourself.
     
    Last edited: Jun 1, 2005
  5. Jun 2, 2005 #4

    Your conclusion is based on a misinterpretation of the meaning of time dilation (assuming I understand what you really mean). There is no absolute time. Time has no meaning except in relation to physical processes. Time is always defined in terms of physical processes. The time coordinate is different from the spatial coordinate--the spatial coordinate is defined in terms of the spatial relationship between two objects, not in terms of the interaction between them. I'm not being very clear at all.


    I'll simply respond to each point you make:

    1a)not sure what you mean, but its been a while since i've touched a relativity text.
    2a) Temporal velocity is a meaningless term, its not even a term. Time passes more slowly for an object in motion, but the object in motion thinks that it is the stationary observer who's clock is moving slowly. There is no difference, because there is no absolute motion or absolute space.

    1a)No. We don't see objects at all. We see photons that have been emitted from or reflected by these objects. Those photons are in the same 'time coordinate' as ourselves, yes. But what where we think an object is based on sight is independent of where it actaully is, we don't really 'see' objects at all. We see where they were when the photon striking our retina left them. That photon is in the same time coordinate as us.
    2b) huh? Where do you get this? Its sound like you're envisioning some absolute clock and since we're running faster than them, they slip behind us in time. No, there is no absolute time. Ten seconds for them, ten years for us, and then we shake hands. They think its been ten second, we think its been ten years. But they have not 'slipped into the past'.


    Your conclusions seem to be based on a loose conception of an absolute time, something which does not exist.
     
  6. Jun 2, 2005 #5
    This sounds correct to me. We only see a single point of a 4 Dimensional object and we do not see objects in the past. We only remember objects from the past.

    Vision is more a 3 dimensional representation of 2 dimensional images. Vision is not 4 dimensional.
     
  7. Jun 2, 2005 #6
    Granted. Forget about photons alltogether and read "measure" wherever I said "see".
    That's a pitty because this is the essential point. We measure time coordinates as a rising or descending function of the spatial coordinate along the direction of motion in an object that moves while we measure these time coordinates to be constant when the object is in rest. We are able to measure multiple points of this object at a single instant in our time (by using multiple clocks on a measuring rod), despite the fact that the timecoordinates of the moving objects do not coincide (or only at one clock). See picture. So we measure the past, present and future of the object all at once.
     

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  8. Jun 2, 2005 #7
    ah physics in a psychological world.
     
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