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Nature of time, real or conceptual?

  1. Apr 18, 2012 #1
    Hi,

    I didnt see specific relative theory and time mentioned on this site that tries to explain the nature of time: http://www.thisistime.co.uk/7.html [Broken]

    I can understand the part of motion and change, which defines time. But the problem is that relative theory of time is used on GPS navigation to correct signal processing and timing. So it seems time is something real thought relative, it can slow down as per Einstein.

    "Atomic clocks have been used on jet planes and satellites to verify Einstein's theory of relativity, which states that time slows down as the velocity of one object relative to another increases." - http://science.jrank.org/pages/618/Atomic-Clock.html

    "Einstein showed that the only way this can happen is if time intervals and/or lengths change according to the speed of the system relative to the observer's frame of reference. This flies against our everyday experience but has since been demonstrated to hold in a number of very solid experiments. For example, scientists have shown that an atomic clock travelling at high speed in a jet plane ticks more slowly than its stationary counterpart." - http://archive.ncsa.illinois.edu/Cyberia/NumRel/SpecialRel.html

    "Special relativity predicts that the frequency of the atomic clocks moving at GPS orbital speeds will tick more slowly than stationary ground clocks." - http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System

    I can find statements, that its been proved by atomic clocks on airplanes and satellites. Now question is, if the ticking cycle of the objects is changed by gravity and speed of the vehicle, which gives the illusion of time is changing OR is time real after all no matter what clock, atomic, mechanical or biological you use, it will be affected?

    Does Einsteins theory also mean, that aging process is slower on high speed, less gravital force affected vehicles? One can think of chemical reactions as a biological clocks...

    And finally when traveller jumps back to the earth from high speed vehicle, I guess the velocity of the earth around the sun and its own axis is still same and traveller and people on earth jumps back to the same time?
     
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Apr 19, 2012 #2
    I've tried to understand this problem from many sides. At some point is was thinking this:

    Starting point of the orbit in case of the earth is relative to four cardinal points of seasons. As well day and night act as a starting points in shorter time scale. But what comes to evolutions of the solar system, one cannot really say the point until we can find some relative point either in whole planetary system or outside of it, maybe fixed to other star. But in all cases its just a matter definition and commonly accepted cardinal point one tries to find out from ever changing parts of the system.

    What I also tried to ask was that if time is bending on sub and/or sur systems in relative theory? Thats fundamental I think because there are vehicles in vehicles in vehicles moving different speeds on space.

    Say a ship moves in speed of light away from the earth. There are a lot of relative speeds we can examine. Compare the movement of a ship, food and supplies on a ship, atoms on a ship that itself are whirling in the half speed of light. Then think of passengers and the space itself, maybe it has a speed as well. Do you compare those speeds to the people that are walking on earth, or people who may orbit the earth with airplane, or to the speeds of the atoms in liver and heart? Don't you need to compare original speed of the ship to the earth rotation and orbiting speed around the sun as well, or against the speed of planetary system which is also moving forward. Was it that clocks got unsynchronized or that biological process got slower and faster? Can you see the problem?

    There is a practical side of the phenomena, time cards. But neither that or the theory of the time is a question of life for me. Life goes on some reasonable way even we get late on work or don't understand how everything works. Its true being late on work may risk a career but as well one ability to prove or disaprove the unexistence of time may be fundamental to some scientists career. I still know people living on land who start their day on sun rise and close it on set. Clocks are not really needed.

    Sure timing is hugely important on operational life. If you dont calculate your going in and out to NYC with a car, you may hit a huge traffic jam. If you calculate wrong when you run across the street, it may even be a question of life. But what we do here is actually predicting the movement and changes of objects to the relative movement of subjects. It could be called time syncronization in essence.

    If Einstein didn't tell that time can get slower, I would never even think about it more. I'd say its relative to the often cyclic moving objects and from psychological side to our conscious and it would be just a concept to understand certain things on world like kinetics and aging for example. But to say time can get slow is same as to claim its as real as space and objects and forces. Its not just a concept, but a fact as we would say. And you can affect, bend and change it with a mysterious speed of light. What makes thing even more complicated is that, before Einstein time was an absolute fact in science, after Einstein it turned to a relative fact. Problem is, that I cannot see it as a fact at all. I can see only energy and changes relative to other changes.

    http://plus.maths.org/content/what-time-0

    Yet one more specific theoretical question is if an atomic clock in a vehicle on equal gravity space compared to other similar vehicle having exacly same clock but moving different speed starts to tick unsynchronized. There is no other forces to affect on vehicle and clock inside, only changing factor is the speed of the vehicle. Am I correct that this is what the special relative theory claims? You see its extremely hard to understand that time really changes, but that the measuring device, in this case atomic clock and its cycles are changing, because thats how we count time...
     
  4. Apr 19, 2012 #3

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Yes, time really does slow down. If we were able to watch a person who is moving very very fast relative to us very closely, we would see them walking slowly, breathing slowly, heart beating slowly, etc. relative to us. Of course, if that same person were able to observe us, he would see us walking slowly, breathing slowly, etc. because he is we are moving very very fast relative[ to him. There is no contradiction there because, as long as we move with constant speed relative to each other, we cannot "get together to compare notes" in the same frame of reference.\

    And this is not just a matter of speed. Time will move more slowly for a person in a strong gravitational field that for a person in a weaker one.
     
  5. Apr 21, 2012 #4
    I've struggled thru hundreds of sites and dozens of forums with this topic. I was having a suspect of the theory myself (well the part concerning time dilation and time concept in general), cause things didn't clue up in my mind. May it be lack of experience and knowledge of the topic, but I found this very recent work and proposal done: http://www.physicsnext.org/

     
    Last edited: Apr 21, 2012
  6. Apr 21, 2012 #5
    markoman, Special relativity was proven a long time ago. Time does actually 'slow down', and distance contracts. After taking a quick look over the website you linked, it appears to be absolute crackpottery. As far as I know, PF doesn't allow the posting of crackput links like that, I'd recommend you remove it.
     
  7. Apr 21, 2012 #6

    Dale

    Staff: Mentor

    Hi markoman, yes, all clocks of any mechanism slow down. If one kind of clock slowed down and another kind did not then the principle of relativity would be violated. Here is a post on the topic:

    https://www.physicsforums.com/showpost.php?p=1561105&postcount=3
     
  8. Apr 21, 2012 #7
    Thanks for the new link and your review of my link. It may take months to go through the material on math.ucr.edu. Is there actual references to the case, that is raised on the physics site? Especially the objective clock and disabling the possibility, that its atomic behavior of the clocks used on measurements, that are causing the time dilution?

    I'd like to see some deeper analysis and quotes on plate, why given site is absolute crackpottery, before removing the link. It doesn't help me much just to say its crackpot, without showing why its so. I'm not linking by means of any insult of people or dishonor the quality of the forum. Its just because I'm willing to learn by questions and asking and drawing conclusions by my own.
     
  9. Apr 21, 2012 #8

    Dale

    Staff: Mentor

    The site is not peer reviewed nor does it agree with the peer reviewed literature. In fact, it is very bold and explicit about it's disagreement with the existing body of literature.

    It is obviously crackpot.
     
  10. Apr 21, 2012 #9
    Thats what the site is proposing, the theory would be violated. So I would ask, how far we have tested, or have been able to test other imaginable cycles of the movements, that differ by mechanics? There was a good set of time keepers on the post you provided. One more would be just to count numbers on mind. Am I correct, that according to SE if I start counting numbers on earth, and my bro on satellite and somehow we manage to keep counting steady and precise whole course of the test, next time we meet on the ground, we will give different numbers for comparison?

    See, I try to figure out many ways to do counting and ticking to eliminate gravity and other physical interference in theory. If I'm correct, its not really matter of per sec or time itself on counting, but relative changing pattern, cyclic movements, that will get offset according to SE.
     
  11. Apr 21, 2012 #10
    Translator to my language gives drug addict, foolish and nonsense for the word crackpot, lol.
     
  12. Apr 21, 2012 #11

    Dale

    Staff: Mentor

    There are four known fundamental forces: electromagnetism, the weak nuclear force, the strong nuclear force, and gravity. The laws that govern all four of them exhibit time dilation. Until we either find a new force or some deviation from the currently-known laws there is no known possible mechanism to build a clock that does not exhibit time dilation.
     
  13. Apr 21, 2012 #12
    An interesting practical application regarding how speed and gravity affect the passage of time is GPS systems: clocks on satellites run at quite different rates than terresitrial clocks.
    So frequent corrections are required to accurately calculate positions.

    check it out:
    http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System#Relativity

    note the chart plots to the right..........

    so it turns out that time and space [distance] are relative even though they appear fixed to our senses; rather it is the speed of light that is constant to all observers.

    time is as 'real' or 'unreal' as, for example, space. But 'real' is a 'real' poor word....
     
  14. Apr 21, 2012 #13
    Firstly, there is no reason to believe motion affects cesium directly, causing it to vibrate less frequently. None. At all. On top of this, the experimental results exactly met those predicted by the equations of special relativity.
    Oh, it's total crackpottery, without a doubt. It meets all of the requirements - not peered reviewed, references no peer reviewed papers, distorts information, is very vague and never gives full explanations, goes against well-understood physics, sensationalizes, etc.
    Those are exactly what a crackpot is. Someone who believes something insane for no reason whatsoever, and is absolutely convinced they are correct. Here is a crackpot test.
     
  15. Apr 22, 2012 #14
    So if I'm brave, I can present 5 statements contradicting widely accepted opinions how things work, still not being a crackpot. Then I should be careful with every word. I wish there is a way to get some - minus points, rather than only A starting points, lol.
     
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