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Can time be considered a direct function of movement?

  1. Mar 12, 2017 #1
    Can it be said that time is directly related to movement? That is to say, on a quantum level, if all motion were to cease, would that not bring about the cessation of time?
    Last edited: Mar 12, 2017
  2. jcsd
  3. Mar 12, 2017 #2
    I'm not sure how best to put it as to prevent any misconceptions about time travel, but according to Special Relativity time flows differently between two frames of reference depending on their relative velocities. You can calculate these differences using something called a Lorentz boost. Check it out here for the actual equations https://en.wikipedia.org/wiki/Lorentz_transformation
  4. Mar 12, 2017 #3
    @TJGilb Thank you sir! That was a very interesting read, (although I confess I don't have the math to fully understand a great deal of the article)....It does however elaborate on some of the research reading I've done in relation to velocity and point of view as it relates to the perception of passing time. But it seems to apply on a macro level. I'm still trying to understand the relationship of movement on a quantum level. I may not be asking the correct question here, but here's my reasoning. Since all matter, or antimatter for that matter (no pun intended lol) is apparently composed of subatomic particles, (If I understand it correctly) which in turn are in a state of constant movement, what would happen if ALL subatomic motion in the universe were to cease? Does it not follow that it would put an end to the function of time altogether? The particles would still exist in space, but without motion, would time still pass since the passage of time involves measurement and without motion, you cannot measure?
  5. Mar 13, 2017 #4


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    That is a very misleading way of describing differential aging. Time flows at exactly one second per second in every frame of reference, it just LOOKS different from other frames of reference. It CAN have a different number of seconds along two different world lines between two events (see the Twin Paradox) but that's differential aging, not differing rates of time flow.
  6. Mar 13, 2017 #5


    Staff: Mentor

    The relationship is the same. The Lorentz transform applies for modern quantum field theory just as it does for macroscopic phenomena
  7. Mar 13, 2017 #6
    Perhaps I worded it poorly. Using Minkowski space-time, taking any path through space-time is given by ##ds^2=c^2dt^2-dx^2-dy^2-dz^2##. So the quicker you move through space, the shorter your path through space-time is. Less time has actually passed for that frame of reference, but I can see how saying it "flowed differently" would be confusing and misleading. With "proper time" being ##dt^2=-\frac {ds^2} {c^2}##.
  8. Mar 13, 2017 #7
    With the caveat that I only have a rudimentary introduction to quantum mechanics at this time, from the way I understand it, that's impossible, and doesn't actually make physical sense. I'm not too comfortable commenting further though. Maybe in a few years when I've gotten further into QM and QFT, but not now. So hopefully someone else can expand on that.
  9. Mar 13, 2017 #8
    Time is a direction in spacetime. Objects have "worldlines" which are like noodles in spacetime. If you look at a certain snapshot in time, you are basically looking at a cross section of all the worldlines. For an object that is not moving (relative to a frame of reference), the noodle is oriented parallel to the time direction. So if you look at different snapshots, the object is at the same position. An object that is moving will have a worldline that is slanted or curved.

    Objects can stop moving in the space direction, but they always "move" forward in the time direction; that is to say, the world lines for the objects always extend to future time slices (unless the object is destroyed).

    With that in mind, we can answer no to your original speculation.
  10. Mar 13, 2017 #9
    @Khashishi explained it correctly. Time does not stop even if the object stops movement time will still move forward.

    A simple example is an apple that was at rest then released from non zero height, the apple will start falling and accelerating towards the ground, but actually the apple was not pulled by gravity. According to Special Relativity the Earth is bending spacetime, and because time is always moving forward (even at rest) the apple at rest will move through time but in a curved space and thus it will take a curved path in spacetime (vs flat path if there is no gravity) which translates to movement towards the ground.
  11. Mar 13, 2017 #10

    David Lewis

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    Can you tell me how fast it is moving in that situation?
  12. Mar 13, 2017 #11


    Staff: Mentor

    1 s/s
  13. Mar 13, 2017 #12

    David Lewis

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    The speed is denominated in what units of measure?
  14. Mar 13, 2017 #13


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    It is clearly dimensionless. Perhaps you should open your own thread on the topic instead of derailing this one.
  15. Mar 14, 2017 #14


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    General Relativity

    The free falling apple takes a straight (geodesic) path in distorted space-time

    Last edited: Mar 14, 2017
  16. Mar 14, 2017 #15

    My bad I was sleepy when I wrote that post lol.
  17. Mar 14, 2017 #16
    "Objects can stop moving in the space direction, but they always "move" forward in the time direction; that is to say, the world lines for the objects always extend to future time slices (unless the object is destroyed)."

    With that in mind, we can answer no to your original speculation.[/QUOTE]

    Thanks! I love that illustration of the intersecting lines, and it is extremely helpful to visualize time that way, but again it seems to function on a macro level only. For example,If the object in question is at rest,(let's call it Macro-motion wise) it's component matter is never truly at rest on a quantum level, because its atoms continue to perform their various circumlocutions correct?

    What would be the consequence of those atomic structures ceasing their various energetic movements? Complete disintegration of the apple on an atomic level?
    But even THAT involves motion because to disintegrate, the atomic particles would have to move away from each other, or else the apple would remain in the appearance of an apple.....Thus my question is the passage of time a function of motion?

    Can it be said that if you somehow managed to stop all motion on a sub-atomic level would time cease to exist?
    Put in reverse, at the instant of the "big bang" did "Time" come into existence as a consequence of the motion of expansion? If so, if that expansion were to cease, down to a quantum level would that in effect stop time? Forgive me if I seem obtuse, I'm just trying to wrap my head around an idea that I don't have the math to describe.
  18. Mar 14, 2017 #17
    No. Spacetime existance is independent on its matter content.
  19. Mar 14, 2017 #18
    It can be said, but it doesn't lead to any meaningful conclusion.
  20. Mar 15, 2017 #19
    Thanks, Rootone.
    @Ostrados, can you cite any published articles that I could read to look into your assertion? The idea that Spacetime is not directly linked to matter and motion seems somehow counter-intuitive.....how can one exist without the other? Can you offer an illustration that could help me visualize that a bit clearer?
  21. Mar 16, 2017 #20
    Can space exist without any matter?

    Mathematically yes, spacetime can exist without matter:

    But physically the question is open to debate.
    Check this:

    If you wish to discuss this topic I think it is better to create separate thread for it.
    Last edited: Mar 16, 2017
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