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B Is time dilation just a problem with our clocks?

  1. Oct 4, 2015 #1
    [Mentor's note: This thread was split off from https://www.physicsforums.com/threa...hift-for-a-static-black-hole-comments.835277/ as clarifying misunderstandings about time in general is off-topic in a thread about the specifics of time dilation around a black hole]

    Loved the post, but is respectfully disagree with use of time dilation. Doesn't gravity affect light and matter? Is it not having an affect on our clock? Clock was designed to work on Earths surface. A change in function of this machine is only a loss of calibration to a different environment. Thus this time piece can work correctly in a stable environment, if it is recalibrated to that environment. So it would be closer to the truth if you said time dilation is only a relationship of the rest of our universe using Earths time. But time is a constant and can't be bent or altered.
     
    Last edited by a moderator: Oct 5, 2015
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  3. Oct 4, 2015 #2
    In addition. I think of it like this. Light traveling from a distant star can be used as a historical record of time. Much like archeologists date objects based on depth of dirt. But no one is saying we can bend the dirt-time continuum
     
  4. Oct 4, 2015 #3

    PeterDonis

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    This is not correct--at least, not for the clocks we use for making time measurements in physics experiments. Yes, a pendulum clock won't work well in space, but the solution for that is not to use pendulum clocks. Clocks based on crystal oscillators, such as an ordinary quartz watch, work just fine out in space. You don't have to "recalibrate" them.

    You appear to be misunderstanding what "time dilation" is. It's not something you observe happening to yourself. To you, a clock you carry with you always appears to tick normally. But someone else observing you from a distance, who is moving relative to you, or who is in a region of different gravitational potential, would see your clock ticking differently.
     
  5. Oct 4, 2015 #4
    Gravity affects all matter my friend. The atomic clock is the most accurate clock avaliable. And it is still affected. Gps satellites must constantly be calibrated back to earth time.
    The astronaut that has spend the most time in space, over 2 years. Only lost .0007 of a second of time. (From memory so may not be 100%. But pretty close)! When he got back to earth it would not matter to his ordinary clock. That's why ur using regular clocks. Because u can't tell unless u have a very accurate time piece.
    Look up experiments of time dilation. It's concept is total right but it is misunderstood and misused.
     
    Last edited by a moderator: Oct 5, 2015
  6. Oct 4, 2015 #5
    All kinds of matter and energy are affected in the same way. So we say that the time itself is affected.
    If you are trying to deny the existence of gravitational time dilation, this is not the place to do it.
     
  7. Oct 4, 2015 #6

    PeterDonis

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    Yes, we all agree on that.

    Yes, we agree on that too.

    Yes, because we need them to keep a time that is different from their "natural" time, the time they would keep if they weren't recalibrated. If you were riding along on a GPS satellite, and had an atomic clock to keep time, that clock would be keeping the "natural" time of the satellite, and the recalibrations back to earth time would look to you like they were throwing the clock off, not correcting it.

    Nobody here is denying that time dilation exists. But if you think it's being "misused", you're going to have to explain in detail why you think that, and give references.
     
  8. Oct 4, 2015 #7

    Boing3000

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    We are saying the exact same thing. The local "proper" time cannot change. How will you prove it change anyway ? (Because all local clock would change the same way)
    That's the relationship (relatively to other frame of reference) of coordinate time that change.
     
  9. Oct 4, 2015 #8
    I'm not saying that gravitonal time is false. I'm saying it is misused. Time doesn't wrap, change, speed up, slow down etc. only the way that it is measured changes. So basically the clock changes. Not actual time.
     
  10. Oct 4, 2015 #9

    Nugatory

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    The "clocks" of relativity are any time-dependent process: the graying of my hair, sand falling through an hourglass, the decay of radioactive atoms, the decay of unrefrigerated meat, the motion of the earth around the sun, the height of the tree in my front yard... Google for "Time is what a clock measures" to see the importance of this insight from Einstein.

    How do you explain the twin "paradox" (http://math.ucr.edu/home/baez/physics/Relativity/SR/TwinParadox/twin_paradox.html) then? Basically two identical twins by definition the same age shake hands; then take different journeys; then reunite to shake hands again. At the reunion, one of the twins has experienced less time and is physically less aged than the other. It's really hard to see how the difference in aging can be attributed to anything except having lived through different amounts of time between handshakes.

    (Note: It's called the twin "paradox" because it's often presented as a paradox in elementary classes as a teaching tool, but in fact it's not a paradox - the correct and non-paradoxical resolution has been understood since the birth of relativity).
     
  11. Oct 4, 2015 #10

    PeterDonis

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    How would you measure "actual time" in order to distinguish the clock changing from "actual time" changing?
     
  12. Oct 5, 2015 #11
    Let's say we have a clock that had two sensor plates and light is bouncing back and forth. For simplicity, we will say every strike on a plate is one earth second. To get earths time, we must put these plates at a certain distance apart, in accordance to earths environment. Therefore we are calibrating it our givin situation. When we change gravity or speed we simply move the plates apart to account for the effects of gravity and speed. Now we have calibrated it to that environment.
    Another analogy is the pulsing of light from celestial objects. If earth telescope looked at a pulsing object in space, would a telescope in space not observe the same pulse at the same rate? (same distance from pulse).
     
  13. Oct 5, 2015 #12
    I'm not trying to argue or be rude. I hope everyone understands that. I am merely saying that our time measuring devices ARE affected by gravity and movement based on laws, simply because gravity affects matter and light. Can we all agree on that? Therefore I'm saying the mechanism is affected. The person with this clock will see no difference because this is his only way to count time, thus his clock is relative to him. But if he knew a pulsing object, in space, had a certain rate, then he could compare this to his clock and see the loss of calibration.
     
  14. Oct 5, 2015 #13
    But how do you explain that all kinds of clock, electromagnetic, gravitational or nuclear, get affected in exactly the same way? Isn't it simpler to say that the time itself is affected?
    Anyway, what's the difference? Everything just happens slower in both cases.
     
  15. Oct 5, 2015 #14

    Dale

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    The problem is that you are saying more than that. You are not only saying that the mechanism is affected but you are also saying that there is some "actual time" which is not affected. Peter asked you to justify that specific claim by demonstrating how to measure this purported "actual time", which you avoided answering.
     
  16. Oct 5, 2015 #15
    I'm sorry. If I sound stubborn. I'm trying to respond to a lot of different posts here. I posted a response to this in another post. I understand it as, a person in space traveling with small gravity will have his clock slow down compared to a persons clock on earth. So when looking out the window he sees the same pulse, from another object in space. Would this pulse slow down for both observers? If so why? Also why does a clock going in a separate direction speed up vs slow down?
     
  17. Oct 5, 2015 #16
    They are all calibrated to same standard and all have matter.
     
  18. Oct 5, 2015 #17
    My questions stay the same.
     
  19. Oct 5, 2015 #18
    According to this, a person can go into space and not age or age very slowly?
     
  20. Oct 5, 2015 #19
    The difference would be huge. Would it have an affect on aging or just the clock? That is what I'm trying to determine?
     
    Last edited by a moderator: Oct 5, 2015
  21. Oct 5, 2015 #20
    The contrary. In the space you age fastest. On the Earth you age at about 99.99999993% of that speed. Close to the horizon of a black hole, you can age at 1% speed or even slower.
     
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