Does Distance exist without time?

Discussion in 'Physics & Math' started by Quantum Quack, May 31, 2008.

  1. Montec Registered Senior Member

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    Hello all
    On word "parallax". Use distances and angles to measure distances. No time involved.

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  3. Vkothii Banned Banned

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    How much time does the measurement take though?
    How much time did it take for the objects in the parallax view to get to where they are, so the measurement is possible?

    I don't really think you can get away from Time if you're looking at Distance.
    In Einsteinian spacetime, they're indistinguishable dimensions - to ensure a theory is consistent with GR, you have to be able to transform time into distance and distance into time, or the math doesn't "fly".
     
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  5. S.A.M. uniquely dreadful Valued Senior Member

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    What is the distance travelled by my words from me to you?
     
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  7. Montec Registered Senior Member

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    Hello Vkothii, et al.

    Parallax is simple geometry and does not have any time variables. Your eyes/brain do it all the time. Two telescopes on opposite sides of the Earth can take a parallax measurement at the same time (thanks to atomic clocks and such). The Earth's atmosphere does tend to get in the way though.

    Parallax will only measure the "point of origin" for the light. How long the light took to transit from source to detector is irrelevant. The source could (and probably did) move (relatively speaking) during the transit time of the light.

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  8. EndLightEnd This too shall pass. Registered Senior Member

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    But you do not get both measurements for the parallax instantaneously, it requires an observer to move through time to a separate point to get a different measurement. So yes there is a time element there.
     
  9. Montec Registered Senior Member

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    Hello EndLightEnd, et al.

    If I where to use the Earths orbit around the Sun to measure the parallax distance to a nearby star what "time" between measurements would be the most beneficial and why so.
    1) Three months
    2) Six months
    3) Nine months
    4) Twelve months

    Point being that if you take the same picture from two separated telescopes (or cameras) at the same time and compare them you will have parallax.

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    Last edited: Jun 1, 2008
  10. Vkothii Banned Banned

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    What do you mean by "at the same time"? How would you arrange to take two pictures of the same star, with two separated telescopes, at the same time, and more to the point how do they get separated?
     
  11. Reiku Banned Banned

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    Before i was rudely interrupted by quarkhead yesterday (and he is wrong: the equation is very much correct), distance is only related to time if an observer is present. This is why distance in relativity is observer-dependant.
     
  12. Oli Heute der Enteteich... Registered Senior Member

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    Or two observers...
     
  13. Reiku Banned Banned

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    End.Light

    No.

    This is wrong...

    ''But you do not get both measurements for the parallax instantaneously, it requires an observer to move through time to a separate point to get a different measurement. So yes there is a time element there.''

    The element is purely based on two observers. Take away the observers, and there is no measurement in distance, and including real time frames.
     
  14. Prince_James Plutarch (Mickey's Dog) Registered Senior Member

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    Quantum Heraclitus:

    First off, I am the one who loves Zeno. Not you. Stop ripping him off, or I will go Eleatic Stranger on your ass, Plato style.

    Seriously. That's a promise, not a threat!

    But what you have here is a somewhat faulty thought experiment to some extent.

    The reason it is faulty is that an absence of time does not shrink the spatial properties. If something is 10 ly away, it will retain its 10 ly away, even if it is meaningless to speak of travel in a timeless state.

    That is to say, distance is a spatial not a temporal property.

    That being said, if it takes two moments (let moment = smallest increment of time) time to move from point a to point b, when point a and b are two arbitrary points in space, you have infinite speed. If no time is taken (impossible) the object would exist at two points simulteneously. But this is neither here nor there whatsoever and has no bearing on the thought experiment.
     
  15. Reiku Banned Banned

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    You can go all Plato on our asses then, while i will go quantum on yours. This is wrong:

    ''That is to say, distance is a spatial not a temporal property.''

    Distance is indeed a spatial quality, or attribute, but since space and time play the same roles, distance must be temporal in this respect. But distance is an observers attribute of measurement, so the rest follows.
     
  16. Prince_James Plutarch (Mickey's Dog) Registered Senior Member

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    Reiku:

    Time does not play the same role as space. It is an entirely different dimension - it measures a non-spatial progression.

    There are also objective measurements based off the speed of light which is held as invariant. The planck length, also, is held to hold in all references frames.
     
  17. Reiku Banned Banned

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    Well, by request, i will show you equations that make space and time invariant.

    Or, if you don't believe those, consider:

    Herman Minkowski (Einsteins Teacher)

    ''We can no longer treat an action space as seperated from time. From now on, physics has taken a monumental turn, where the space coordinate plays exactly the same role as the time coordinate.''
     
  18. Quantum Quack Life's a tease... Valued Senior Member

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    except that for the three objects to exist 1 second had to pass... so time is very relevant to the obects dimensionality
     
  19. Oli Heute der Enteteich... Registered Senior Member

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    Why?
     
  20. QuarkHead Remedial Math Student Valued Senior Member

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    Reiku: Humble pie is a dish that has long been my staple diet, of necessity. So, if you would be kind enough to explain your equation, or better yet, provide a link, then I would be glad to take another slice.

    Yet you seem strangely unwilling to do this. Why? If it is a "well known equation", surely there can be no secret about it?

    Come on, help me out. As you know, unlike you, I am not a physicist, and I need help from time to time.
     
  21. Quantum Quack Life's a tease... Valued Senior Member

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    Well how many dimensions exist if an object stops moving with time?

    If energy [ light ] suddenenly froze and stopped moving.
    Suspending animation!

    I would suggest that maybe only 2 dimensions exist as one would note in a photograph.

    so if you take a photograph which shows a man in the foreground and a mountain in the background and with imagination you calculate the distance twas approx. 7 kms between man and mountain. What are the actual distances involved?
    zero! as the picture is a 2 dimensional object [ not counting the ink and paper of course.] and there is zero distance between man and mountain. It is only an illusion that when time is frozen that there is distance. Our ability to imagine time comes to the for.

    So when we take a snapshot at any given moment what are the distances away from the camera shown in the picture taken?
     
  22. Oli Heute der Enteteich... Registered Senior Member

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    Ummm, 3 spatial and 1 time dimension...

    Speculation.
     
  23. Enmos Valued Senior Member

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    What about perspective ?
     

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