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B Time slowing because of speed

  1. Mar 1, 2017 #1
    it is known that einstein's theory has been verified and time slows down for particles that should decay in certain time, takes more time to decay if moving fast.

    what makes them behave like that, how moving fast makes time to slow down, is it really time or just maybe this has not been verified in greater scales, it is just because movement influence the inner parts and it decay slower?

    thank you
     
  2. jcsd
  3. Mar 1, 2017 #2

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    The time slowing down has been verified at the molecular level. Processes in GPS satellites must take both special and general relativity theories into account or they get bad errors. Atomic clocks have been taken to the top of a mountain and behaved as GR predicted.

    Why this happens is a direct consequence of the speed of light being constant even relative to moving reference frames. To make that all work out, it must be that time in a relatively moving frame appears distorted.
     
  4. Mar 1, 2017 #3
    ok, but why should time be affected by speed?
     
  5. Mar 1, 2017 #4

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    When a reference frame is moving, the concept of "simultaneous" becomes ambiguous. Because the moving frame still measures the speed of light as c, its clocks must be set more and more differently as they are separated in the direction of motion. So the moving frame and the "stationary" frame do not agree on whether events separated in the direction of motion happened at the same time. A complete answer would explain why the speed of light is, in fact, constant. I do not know enough to answer that.
     
  6. Mar 1, 2017 #5

    Nugatory

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    The effect is a consequence the fact that the speed of light is the same for all observers, regardless of their speed. The easiest way to see this is to consider a "light clock" - you can google for that, and search here for threads... If that doesn't explain it, you can try asking followup questions here.
     
    Last edited: Mar 1, 2017
  7. Mar 1, 2017 #6

    Dale

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    Time dilation has been observed with particles like muons that don't have any inner parts.
     
  8. Mar 1, 2017 #7
    I think from your first post "it is just because movement influence the inner parts and it decay slower?" you are maybe assuming that movement has some kind of mechanical influence over a particle to make it decay slower, or a clock to make it run slower. That is not the case.

    Consider that you are in the rest frame of a clock and consider two observers, moving at different speeds with respect to you. Your clock would be running slower by different amounts to the two observers. Your "movement" is different according to each observer. There is no such thing as absolute speed or "movement" that would be affecting the inner parts of the clock.
     
  9. Mar 6, 2017 #8
    so what happned to them if they couldn't change in time since they dont have inner parts?
     
  10. Mar 6, 2017 #9
    i'm glad you helped me focus my question.

    i believe the fabric of space is somehow control the speed of light. gravity, as acceleration, known to "make time slower", and gravity isnt a spectator moving issue - but unlike it sounds - i see it as reinforcement of my idea.

    " Your "movement" is different according to each observer." different in what way?
     
  11. Mar 6, 2017 #10

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    To a moving observer, absolutely nothing has changed. To an outside, stationary observer, the timing of the moving observer is wrong and everything measured by the moving time is wrong. It's all about how time is measured.
     
  12. Mar 6, 2017 #11

    Dale

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    Usually it decays into an electron and two neutrinos. But those particles are not "inside" the muon before the decay.

    You probably should focus on learning the existing science before trying to make a new theory. Also, until your idea is published in the professional scientific literature it cannot be discussed here.
     
  13. Mar 6, 2017 #12
    By that I just meant that your speed relative to each of the two observers is different.
     
  14. Mar 6, 2017 #13

    Grinkle

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    Nothing happened to them. As far as they are concerned, they are decaying at the same rate they have always decayed.

    One must pick a theory, predict the consequences, and experiment to test the theory. If the time between two events is always the same for all observers, then the speed of light could not be the same for all observers. This does not mean that anything is modified or different in the particles that are being observed. It means that (now I am about to say some things that are at best half right) the passage of time is not a universal constant.

    If I am in a train moving next to another train at the same speed, I can think of the other train as stationary. An observer next to the track will say both trains are moving at some non-zero velocity. One doesn't ask what has changed in the two trains to make the observer say this. Its just a different perspective. The rate of time passage is the same way - its a matter of perspective. That is not at all intuitive. We know it must be the case because if one follows the logic of SR either that is the case or the speed of light is a matter of perspective, and experiment contradicts that latter theory.
     
  15. Mar 7, 2017 #14
    how time is measured?
     
  16. Mar 7, 2017 #15
    how the speed/movement of the muon made it decay more slowly for those who measured it?
     
  17. Mar 7, 2017 #16
    what makes speed of light same always? maybe the answer to that would solve my problem. why everything except propagation of light is relative?

    as for my theories, maybe it's better not to reveal them here cause you cant discuses all the crazy theories that people might suggest online and i want the noble prize for my self one day anyway :)
     
  18. Mar 7, 2017 #17
    i'm trying to separate between time and the observers of time. dont forget that when you move away from me (in constant speed) it's the same (except dopler effect in EM) as me move away from you. why then your "time" will seem - seem?? should be without seem i guess - different
     
  19. Mar 7, 2017 #18

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    Remember that when the beginning and end times of a process in the moving frame are measured, they are at different locations in the stationary frame. The moving and stationary reference frames can not agree on how clocks can be synchronized along the direction of relative motion. If they agree at one point, they must disagree at all other points in that direction. This is true of any type of "clock" system -- whether they are based on physical motion, on atomic processes, on the physical aging of a person, or anything else you can imagine.

    How do we know this? Because long, hard efforts were never able to detect the slightest difference in the relative speed of light in a moving versus a stationary frame of reference.

    Why does this happen? Only God knows.
     
  20. Mar 7, 2017 #19

    Dale

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    That is exactly the point. There is no mechanistic explanation possible since the muons have no sub structure. The only explanation we have found is time dilation.
     
  21. Mar 7, 2017 #20

    Dale

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    If you assume that the laws of physics are homogenous and isotopic and obey the principle of relativity then you can show that there are only two possibilities: Galilean relativity or special relativity (see https://arxiv.org/abs/physics/0302045v1 ). It is then just a matter of experiment to determine if the invariant speed is infinite (Galilean relativity) or if the invariant speed is finite (special relativity).
     
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