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Back with more relativity questions

  1. Sep 3, 2013 #1
    So a year or so ago this question about traveling at light speed and its effect on aging in relation to a view point started swirling around in my head and I came here for answers. I got a few and they kinda made sense.

    This is one explanation I got "First, the reason its called "relativity" is that you can only talk about "approach the speed of light" relative to some reference point which we take to be "stationary". A person who is "stationary" would observe a person moving close to the speed of light (relative to him) moving and living slower- if he were able to see a clock on that space ship, he would observe it moving slower than his own. Of course people in the ship would not observe any change in themselves.

    Now this is whats been buggin me, the above may be true, but from a possible vantage/belief point, time started when the universe came into existence and as such the speed at which you travel within it does not change the interval in which the universe has been around and is ticking/creating the one that is traveling at light speed.

    Yes this interval from when existence started could be broken down into any number of measurements, but none the less its independent of whats going on in it (like light travel or faster).

    I could see that ones "perception" of time is changing in relation to speed, but non the less the object time line that was started when creation/existence came into being is unaltered.

    For example lets say creation came into existence 2000 planets ago (I'll use the creation of planets as a measuring of time from its start).

    Now at 2000 planets time, one planet launches 2 ships into space at different speeds. Lets say one is launched at what we consider light speed and the other at half that. Lets say 1 light year = 2 planets of real time, meaning a planet will be fully formed in 1 light year.

    So in 1 light year a ship will have reached its stopping point at 2002 planets time, and the other at 2001 planets time.

    So how does relativity hold up here if this is the real case of time passage. It would seem to me that objects traveling at what ever speed and being viewed from what ever vantage point are ticking at a rate = creation itself. Yes clocks and human aging may slow in relation to light speed but what ever it is that makes up clocks/humans/light all started and exists within a ticking separate from speed. That ticking is the age of when the universe started divided by what ever interval you want to divide it by and to me wouldnt seem to change in relation to how fast its moving.

    For example the clock experiment moving in a speeding object for X amount of "time" showing to be 10's of billionths of a second different than when it was stationary, is none the less a clock made from materials that started at the creation of time and are ticking at their own interval independent of the "time measuring mechanism" that it is and was ticking at.

    Again I could see the possibility that a human traveling at light speed would not age visually and they experienced a distortion in their own time experience in relation to those at rest around them, but none the less the energy/matter/creation/light that makes them up to be human is none the less as old as the independent ticking of the universe and speed does not change this objective ticking.
    Last edited: Sep 3, 2013
  2. jcsd
  3. Sep 3, 2013 #2


    Staff: Mentor

    There are four fundamental forces: EM, strong, weak, and gravity. All 4 show time dilation. It doesn't matter how you attempt to objectively measure the age, you will find that it is the time dilated age and not the age determined by "the independent ticking of the universe". The "objective ticking" you are wishing for simply does not exist.
  4. Sep 3, 2013 #3
    So are you implying then that rate in which the universe is expanding/evolving/reacting/redistributing/complexifying is not actually happening to someone/something traveling at light speeds, even though that person/thing is foundationaly and simultanously a part of the origin/process that did take place at a given point/time?

    Again it would seem, from the point of creation to 2000 planets, some manner of transformation/time happened. Wether something/someone was traveling at light speeds during a given interval of 0-2000 planets, the age of the traveler/object is always ticking at that measurement, since the object itself is the measurement.

    To me it would seem, in order for light travel to happen there needs to be space for it to travel. I'd imagine an event of stuff happened from the point of creation till light existed and distance was formed for light/object to travel at any particular speed. This would mean a passage of events took place (time) even if no one was there to measure it.

    This would mean that this passage of time that took place before light and distance were created is still passing/taking place independent of light/object traveling over a distance.
    Last edited: Sep 3, 2013
  5. Sep 3, 2013 #4
    Your question seems to be asking, "If I have two clocks that were set to the same time, and then later found them to show different times, what does it really mean that they show different times? How can we conclude that one clock is older or younger than the other when clearly both clocks have "been in the universe for the same time", since the universe had a precise beginning and we are reading the clocks right in front of us locally right "now"?"

    What you are calling the creation time is currently estimated at about 13.8 billion years ago and the physics works back to within a tiny fraction of a second after that. This does suggest that the universe began at a pretty precise starting time.

    It might also seem that everything in the universe must be "the age of the universe" old - that is, everything in the universe is the same age, same age as the universe.

    But what happens when you discover that clocks slow down when they move around? And even determining which clocks are slower than others becomes a problem depending from which vantage point you chose to measure other clocks... it looks like there is no absolute motionless position from which to judge all the clocks so there is no absolute time to which the clocks may be compared.

    If there was a special kind of super clock that did not lose time when it moved (objective ticking) as Dalespam says, then the ordinary clocks' lost times from motions could be used to establish absolute motionless in space.

    With no absolute time (objective ticking) or absolute space (motionless position), it seems that if you have two clocks showing different elapsed times in front of you, you must conclude that one of the clocks has "lived longer or shorter than the other" even though the universe had a precise start and you are looking at the clocks side by side right "now".
  6. Sep 3, 2013 #5

    Hey thanks for some response and your own observation on the matter. In response to what you said, I ask you why does there need to be a super clock to tell us that time is passing at a certain interval to know that time is passing? From a conceptual stand point we know that the universe started at a point and now/or what ever point after you want to compare it to is a later point. All things that traveled, the speed at which it travel and the distance itself in that conceptually time span were taking place IN that time span. The object traveling does not leave that time span, the object, the speed at which its going and the distance its traveling is getting older in relation to the when the universe started and when this event is taking place.

    I guess what I'm seeing and saying is speed and distance "itself" ages at an interval of X-N. X=the start of creation and N = when ever the object you are measuring came into exsistance (this includes light, a given distance, a personal experience of time, gravity).
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