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Are we travelling slower through time due to the Earths orbit?

  1. Jun 12, 2012 #1
    Is it that faster we move through space, the slower we move through time?

    Is it that we're moving slower through time than if the Earth wasn't orbiting anything?

    And on a wider scale like, the Sun orbiting the centre of our galaxy, and our galaxy moving through space.

    How would time be different if we weren't moving in space?

    We must be moving at a fair pace through space with all this orbiting going on.
     
  2. jcsd
  3. Jun 12, 2012 #2

    sophiecentaur

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    Slower for whom?
    All motion is relative so the question is not trivial to answer. For someone on a space ship that was not orbiting the Sun (just hanging there and using its engines to cancel out the Sun's pull) then clocks on Earth would appear to be going slower than the ship-board clocks. BUTTTTT, to an observer on Earth, the ship's clocks would also appear to be going slower than the Earth clocks. This is a consequence of Special Relativity. The clocks would only agree if the ship were also in orbit, parallel to the Earth.
     
  4. Jun 12, 2012 #3
    There's a contribution of special relativity that causes time to move slower in the earth frame with regard to the sun frame. However, there's an opposite effect due to general relativity which causes time to move slower in the higher gravity in the frame of the sun. You can calculate both effects.

    This is also a significant matter with regards to the GPS system. Here, the contribution of general relativity is greater if I recall correctly.
     
  5. Jun 12, 2012 #4
    How fast are we moving through time please?
     
  6. Jun 12, 2012 #5

    HallsofIvy

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    One minute per minute!
     
  7. Jun 12, 2012 #6
    I don't get it.
     
  8. Jun 12, 2012 #7

    HallsofIvy

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    Then perhaps you should explain what you mean by "moving through time".
     
  9. Jun 12, 2012 #8

    sophiecentaur

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    You rascall, you!
     
  10. Jun 12, 2012 #9
    Well we're going forward through time, like, stuff happens...so we're not, not moving through time, and stuff doesn't happen that has already happened so we're not going backwards through time. Which must mean we're going forward in time. And if we're going forward in time...we must be going forward at a certain...speed? Because...we could be going through it slower or faster, but we're going through is as we are.

    I don't know if that makes any sense.

    How fast are we moving through time is my question.
     
  11. Jun 12, 2012 #10

    sophiecentaur

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    The only real answer to that, is the one given earlier -"One minute per minute". The two clocks in my hand will agree with each other. Personally, I would use the phrase "experiencing time" rather than "moving through time" because 'moving' implies some sort of direct control, which we don't have.

    The point is that everyone has their own, personal clock, the speed of which is governed by how fast they are going relative to other things and people and how near they are to other objects with mass. Two people, side by side will agree that their own clocks are synchronous. The more different their position and relative speeds, the greater is the disagreement between their two clocks. Time is no more absolute than position or velocity - it's just a general consensus of people here on Earth - and even that's not exact.
     
  12. Jun 12, 2012 #11

    Nugatory

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    Imagine that you have wristwatch with a sweep seconds hand. The speed of that hand moving around the face of the watch tells you how fast the watch is moving through time, and because you're in the same general neighborhood as the watch, that's how fast you're moving through time as well.

    So if you want to see how quickly something is moving through time, that's easy - attach a clock to it and let the clock tell you.

    But you started with a different question, are we moving more slowly through time because of the Earth's orbital motion....
     
  13. Jun 12, 2012 #12
    [EDIT:Well Centaur has already answered it, but ill say the same thing again, with more elaboration.]

    I guess its relatively relative. If you measure the speed of a bird in a moving car, and then from the ground, both will yield very different results.

    But we need to define what 'Speed' or 'Rate' first to apply it in 'time's' case. According to me, it is The change of a position/value of variable with respect to the change of another variable whose speed is constant in the observer's frame. When both variables are of same physical quantity, but of different frames, we get a ratio.

    For Example, When the car moves through a distance X, the bird moves through a distance Y.

    Here the Change of position of the Bird w.r.t the change of position of car = Y/X.

    Now, when we come to Speed:

    When the bird moves through a distance of Y, the time in the car moves through a gap of 2 seconds.

    Here, the Change of position of bird w.r.t the change of position of time in the car = Y/2 m/s.

    Let us come to the (Speed/Motion/Rate of Travel) of Time.

    If you put a LARGE Digital Clock on Mars, and an accurate atomic clock on Earth, then you can find a "Ratio" buy using a telescope and omitting any speed-of-light errors.

    When the time on mars changes by 2 seconds, the time on earth changes by 2.000...001 Seconds.

    So, the ratio here comes to about: 1.0000...05.

    Now comes the question, How do we define Our speed Through time?

    Now there are 2 speeds of time, one is Mental, and the other is Physical.

    Mentally, when your brain processes increase/decrease speed of time can change.

    Physically, we need to find our "Change of Our Position Through Time" and "The change of position of Time" during the same interval.

    Since we are trying to finding the change of position of Time in OUR reference w.r.t. the change of ABSOLUTE time, its a ratio. ALL ratios are relative until you set an ABSOLUTE reference frame for yourself, in our case, THE EARTH.

    Hence, you are travelling through time as fast as Earth is, you are up to speed!

    Otherwise, you will have to find another Variable whose change is constant w.r.t to another variable whose.... and the loop goes on.(if you get what i mean, and most likely you havent, my english isnt good)

    The aim of this long post was to Signify how difficult it can be to find a speed of time.
     
  14. Jun 12, 2012 #13

    Drakkith

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    There is no concept of a velocity through time, as we have defined velocity to be change in position over time. Using a lorentz transformation one could say that we are always traveling at c in our rest frames, meaning that we travel at c through time, but c is a velocity and we don't measure time in meters/second. The most accurate thing I could say is that we have defined our units so that light travels about 300 million meters in one second, and since the speed of light is invariant in a vacuum that means that everyone's second is approximately the time it takes for light to travel 300 million meters through space. AKA we travel one second in time for every 300 million meters a beam of light would travel.
     
  15. Jun 12, 2012 #14
    Now That is, relative. You have defined a constant C which is speed of light. Then you are measuring time relative to it. But its still a ratio and does not answer the the question in a literal sense.
     
  16. Jun 12, 2012 #15

    Drakkith

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    There is no way to answer it in the "literal sense", whatever that means. From YOUR frame a beam of light travels 300 million meters in an interval of time. We have defined that interval as one second. The only way to measure a change in time is to relate it to a change in space, and vice versa. You cannot separate the two, it will always be a ratio. In my opinion answering this question with "one second per second" is like saying the velocity of something is "one meter per meter".
     
  17. Jun 12, 2012 #16
    By literal sense, i meant to say something which is otherwise "Time travels as fast as it does on Earth." and elaborate on the topic right from a basic point of view with minimal assumptions.

    I agree your opinion on those ratios. I guess the asker has achieved a satisfactory answer.
     
  18. Jun 14, 2012 #17
    This is a simple definition. However, is one meter same for everyone?
     
    Last edited: Jun 14, 2012
  19. Jun 15, 2012 #18

    sophiecentaur

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    Everything is different for everyone except the value of c that they will measure. If you start from a different standpoint from that then you will just get a scientific model that doesn't work.
    "Travelling through time" is a phrase that makes no sense, in fact.
     
  20. Jun 15, 2012 #19

    jbriggs444

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    Well, travelling through your own personal time... Yes, that makes no sense. Time passes for you at the rate that time passes for you.

    But suppose, for the sake of argument that we had a "speed 'em up" booth within which all physical processes were speeded up. From outside the booth we could look in and see the occupants cramming for finals and finishing term papers in record time.

    Of course, for the occupants, time would appear to be passing normally. The second hand on their wrist-watches would still advance at the same old rate, "one Mississippi, two Mississippi, three Mississippi".

    If the occupants were to look outside, the rest of the world would appear to have slowed down.

    If we had a "slow 'em down" booth, the roles would be reversed. This would allow for "travel in time" with the rate of externally measured time passage being distinctly greater than the rate of internally measured time passage.

    But as a practical matter we can agree that there are no situations where an observed asymmetry in the relative rate of time passage is great enough to merit the use of language such as "travel in time".
     
  21. Jun 15, 2012 #20

    sophiecentaur

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    If you really want to talk of time travel, then, when you do it, you travelling 'in' someone else's time. They are the ones who will see something odd happening to you. You will / could be quite unaware of it.
    I think these discussions could be more fruitful if there were more concentration on what the observations would be and not on what is 'actually happening'.
     
    Last edited: Jun 15, 2012
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