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Time as the 4th Dimension

  1. Aug 27, 2004 #1
    Hello, this is my first time posting, I do hope I've found the right place.

    I have relatively no knowledge of physics but am about to minor in it in college. The questions and ideas I am about to set down concern time, an issue of which I again know very little.

    While sitting idle one day it occurred to me that I wasn't really aware of what time was, I had no definition for it and was only vaguely aware of it's concept in enough to understand the importance of it's passing. After much thought I came up with a definition which in all logic seems correct to me however it appears to go against the idea that time is the 4th dimension. The definition I was able to come up with is as follows:

    "The change in the relative positions of all objects in a dimension due to the exertion of energy."

    The first point: Time necessitates change, does it not? For how else would it be said to be passing?
    The second point: Time must include all objects and their relative positions to one another. If all objects maintain the same relative positions then nothing is changing and that would mean there was no passage of time as indicated by the first point. At the instant one object moves time occurs because that causes an instant change in the positions of all other objects relative to itself.
    The third point: Time occurs within a dimension because it's passage is dependant upon the change of the already physical dimensions of the objects.
    The fourth point: I don't know what brought about the mentioning of the exertion of energy being the cause of it all, it seems relevant.

    Now the problem arises when the definition is put together. A dimension is a physical property or measurement that can be moved around in. For example height, width and depth are all physical properties that can be moved around in (i.e moving along an x, y or z axis). However, this is not so with time. You cannot move in time and it's measurement is much more complex than just height, width or depth. I say that time cannot be moved around in because of my definition. My definition says that time is a result of moving, not a causation. Things don't move because time passes, time passes because things move. Also things are not necessarily moving forward in time or progressing, just changing which does not indicate movement in any particular direction. You could not travel back in time unless every atom was reverted to the same position it held at that given time. Even if this were possible you could say that it merely existed in the same state a second time after it existed in that state the first, however, if it were exact it's previous existence in this state would have no bearance on it's current existence or the time between thus making it seem that the time between did not occur at all.

    As pertaining to the measure of time I came up with this. I have no idea what I am doing, I know basic Algebra and am familiar with Einstein's theory of relativity as is just about everyone (e=mc^2, energy equals mass times the speed of light squared) so what follows is probably an overly simplistic combination of the two. When I looked at my definition I noticed out of complete coincidence the following:

    "The change in the relative positions of all objects (read mass) in a dimension due to the exertion of energy."

    This of course brought to mind Einstein's theory of relativity, but the elements of changing positions/distances and time that are in my definition seemed to be missing. So here comes the algebraic reworking...

    energy = mass x speed of light (299,792,458 m/s)

    So within the speed of light we see elements of a distance and time. I reworked the equation into a generalized form of time = square root of (mass x distance^2 / energy). I know this is flawed, I'm doing this off a scrap paper because I don't have my further calculations handy. If you plug in the above given measuremnt for c then you should come up with something along the lines of 1 sec = etc. This whole part is probably hokey anyway... But I do hope it illustrates my point that the measurement is much more complex.

    Anyway, that's my case, sorry for rambling. I admit to not having done much research before posting this topic, as I stated previously my knowledge is minimal. All attempts failed miserably in subject matter that was either over my head or of a very basic nature. I guess I'm somewhere in between and I need someone to explain these things to me in those terms, particularly why everyone says time is the 4th dimension :uhh:
     
  2. jcsd
  3. Aug 27, 2004 #2
    Welcome to the club.


    You are thinking, and that is a good thing. Keep up the good work.

    You suggest that time necessitates change. Why do you think that time is a causitive factor for change?

    Your second point is not bad. However, you suggest that at the instant one object moves time occurs. Why not: With the passage of time, all objects change their relative positions?

    I am not sure that I follow your third point. I recognize that you are using time only in the context of post Big Bang, where time is bound up in space as space-time. The passage of time is accompanied by a change in the relative position of all of space.

    The fourth point: I don't personally like your use of the word exertion. All of space in the universe is always in motion. This motion is motion both through space and through time. Now, post Big Bang, there is no stillness in space or time. All motion in space requires time. All of space is in motion, and all motion through space requires time, such that all of space is bound up with time, as space-time.

    Why do you say this? We move though time our entire lives, just like everything else in the universe.

    I agree.

    I disagree with this. I think that time flows, and as time flows there is motion in space. By your saying that time is a result of moving, you are separating time from space, are you not? You are thus avoiding the concept of space-time, are you not?

    Why do you say this? Does not time move forward?

    Correct. An impossible situation. Yet, time does move forward, does it not?
     
  4. Aug 27, 2004 #3
    "You suggest that time necessitates change. Why do you think that time is a causitive factor for change?"

    Actually, I was thinking quite the opposite. Time occurs because of change. Time is the result or our perception of change. That's my fault, I was typing hurredly to get the ideas out of my head before I forgot them.

    "Your second point is not bad. However, you suggest that at the instant one object moves time occurs. Why not: With the passage of time, all objects change their relative positions?"

    I suppose this point is still hazy for me. It seems that when we see objects changing there relative positions we perceive this as a passage of time. We SEE the objects moving and interpret it as time. We don't SEE or FEEL time and interpret it as the result of moving objects. Like I said, hazy, but do you understand?

    "I am not sure that I follow your third point. I recognize that you are using time only in the context of post Big Bang, where time is bound up in space as space-time. The passage of time is accompanied by a change in the relative position of all of space."

    I'm not sure here, maybe I'm out of my league.

    "The fourth point: I don't personally like your use of the word exertion. All of space in the universe is always in motion. This motion is motion both through space and through time. Now, post Big Bang, there is no stillness in space or time. All motion in space requires time. All of space is in motion, and all motion through space requires time, such that all of space is bound up with time, as space-time."

    Again, out of my league here, but you say that motion REQUIRES time. I think time is the result of motion.

    "Why do you say this? We move though time our entire lives, just like everything else in the universe."

    I guess this borders on philosophy but how does one "move" through time? Can you explain this movement to me? Certainly things change, yes, but as for movement or direction (forward) I don't know.

    "I disagree with this. I think that time flows, and as time flows there is motion in space. By your saying that time is a result of moving, you are separating time from space, are you not? You are thus avoiding the concept of space-time, are you not?"

    Yet again, out of my league. Maybe I don't fully understand space-time and should do some research, I'll get on that. But am I really separating time from space? It seems to me that if I consider one dependant on another that they are not separate. Is it because I've made one dependant on the other instead of having them work together?

    Perhaps on looking back this is more of a philosophy question though I still feel it is best addressed from a scientific view. Why must time be a "thing" or a "force" or whatever. What if it is simply a "perception" for interpreting? Along the lines of seeing, hearing, tasting, smelling or feeling. Time is just the another way in which we interpret the way physical things around us change and affect us, that's all. Perception not a force...
     
  5. Aug 27, 2004 #4
    When you reply, if you hit the quote button instead of the reply button, you will get a nicer quotation box, like the one above this sentence.

    Your question is one that many people pose, and many people believe. I will not tell you that it is wrong, or that you should not believe it. I will only tell you that I do not believe it.

    This does fit in line with the top citation above.

    I agree.

    I agree. People have a perception of time. That is significant, and has to do with what time actually is. However, I think that you are limiting time to perception, which I believe is not accurate.

    In an earlier time in your life, you were smaller, younger, etc. You have moved through time to reach your present.

    There was a Big Bang. This caused space-time to expand outwards. This expansion takes time. As time moves forward, this expansion continues. Time cannot stop, and time cannot flow backward. As time moves forward, space, which is bound to time, is also in motion.

    If you are considering time as your perception, as I believe that you said that you are, then you are separating time from space, in my opinion.

    To understand this, I suggest that you investigate and ponder the concept of space-time. With space-time, time and space are each dependent upon the other. For example, a change in the rate of motion through space or time is accompanied by a symmetrical and opposing change in the rate of motion through the other.
     
  6. Aug 27, 2004 #5
    So you're telling me what I have stumbled upon is more of the philosophical argument of Realism here, that is does time exist only as we perceive it (what I believe) or that there is more to it (what you seem to believe)?
     
  7. Aug 27, 2004 #6
    It can be a philosophical argument or a physical argument. Philosophical arguments are certainly easier to become invoved with.

    I believe that the first describes you, as you seem to be saying. The second certainly describes me.

    I will not tell you that you are wrong, that your approach is wrong, or that you should accept my position. You asked for opinions, and I provided you with mine.
     
  8. Aug 27, 2004 #7
    Differing opinions are exactly what I was looking for, thank you greatly for your help. At least now I know that there may be something to my ideas and they should not be immediately discarded.

    I must certainly do more research, it is indeed easier for me to take the philosophical side given my lack of knowledge. I now need to understand the physical side to make a better judgement, you've given me much to think on :biggrin:
     
  9. Aug 27, 2004 #8
    Wow, it really seems time is one of the most puzzling and least understood features of our universe, it's still the subject of so many of the threads and posts here! (including myself :-) !

    I really hesitate about what's my own stance (let me first say that I'm no scientist), but some aspects push me towards Audax side, that the passage of time is more a perception rather than an objective physical phenomenon ..... but the discussion can get really deep and I'm humble enough to let scientists and philosophers have the last word.

    One of the reasons pushing me towards the "perception" side is the fact that as widely expressed by relativity, the rate of passage of time depends on the observer, to the point that it could even appear to nearly stand still relative to other observers.
    This pushes me (even if not conclusively) to put it in the basket of SUBJECTIVE phenomena rather than in the basket of OBJECTIVE phenomena. By definition objective phenomena should not depend on the observing subject.
    If the flow of time was a fundamental physical phenomenon, it should not care at all about observers, their relative velocities etc. It should not change its behaviour just because who and how is looking at it.

    Yet I certainly believe it's a dimension of the events in our universe. I would say it's a sort of perspective or dimensional extension, not so much different from perspectives in the spatial dimensions sense, yet with the particularity that we can not see it's total extension at once, but only one point (instant) after another.

    But I admit I'm not conclusive at all. One concern with this view that the passing of time is subjective (and therefore all times, past present and future do in fact all co-exist) is this: the rock 1 minute ago and the rock now are "the same rock"? when we think that time is objective, one unique rock can "move" through time, when it will be at some place/moment in spacetime, it is not anymore in the spacetime position it was 1 minute ago.
    But if we believe that the flow of time is subjective (all of the times co-exist and it's just our conscious ego that "sweeps" though them) we are led to believe that there are as many "rock copies" as instants in which the rock is present.

    Was the rock we saw one minute ago the very same rock that we are seeing now?
    Can a single atom be in multiple positions of spacetime (infinite copies of itself one in each time instant)? If so, is it really one single atom?
    or is it a single and unique atom really "moving" through spacetime, leaving the place behind empty as he moves to the next spacetime coordinate? (able to be at only one position at once)

    Hmmmm, getting a bit too deep for 4 o'clock in the morning ...... ?
     
    Last edited by a moderator: Aug 27, 2004
  10. Aug 27, 2004 #9

    chroot

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    Time is considered a fourth dimension in relativity theory because relativity deals with events. Just like a carnival, an event is something that happens at a specific place at a specific time. If you want to meet your friend for a ride on the ferris wheel, you must specify three spatial coordinates and one time coordinate. Thus, our universe is four-dimensional -- three of space and one of time.

    You need not make this more difficult to understand than it really is -- that is the entire reason.

    - Warren
     
  11. Aug 27, 2004 #10
    I see your point chroot, I think that was perfectly blunt enough to finally push the point home for me.

    Even so with time being the 4th dimension I still continue to question its exact nature.

    I'm not entirely sure what you're talking about Gerinksi, why does a subjective view of time lead you to the idea of a coexisting past, present and future? And multiple rocks? This simply sounds too complex. What I am actually trying to do is to break time down into the simple idea of perception. 1 second would be the same as any other unless something moves and creates change.

    It is getting rather late and my mind is detiorating (as is my spelling because I know that's not how you spell that word) so I think I'll leave any further thought to a time when I'm more rested...
     
  12. Aug 28, 2004 #11
    In other words, you reject relativity because it introduces the idea of relativity?
     
  13. Aug 28, 2004 #12
    It's not that I reject relativity.
    But I think of relativity more as a rule dictating how the universe will appear (how will it look like) to any particular observer, rather than a law exerting any actual physical changes or effects on the universe.

    I believe the real state of the universe must be one and only one, but it can look different depending on the observer (i.e. distances or object lenghts may appear to be longer or shorter, changes may appear to take longer or shorter time to happen etc).

    It's like a DVD film of a concert with different choices of camera angles. Relativity will just dictate which camera we see through.

    BTW, some aspects of relativity theory are certainly laws dictating how the universe behaves (such as gravity). I refer here to the relativistic effects, which are not about dictating how the universe behaves but only about how does it look like.
    i.e. relativity does not say that a planet will follow 1000 different orbits around a sun, it clearly dictates that it will follow a precise unique orbit. Yet relativity also explains that that unique orbit may look 1000 different ways to 1000 different observers.
    And I think what relativity says about the passing of time belongs more to this last category.

    BTW, Chroot was actually so right, that's all you need to understand. But if we wouldn't from time to time wonder a bit beyond, science would be less fascinating :-)
     
    Last edited by a moderator: Aug 28, 2004
  14. Sep 20, 2004 #13
    Time

    Can someone explain to me why I keep comming across this?

    11:11=4th Demension=Time

    :surprised
     
  15. Sep 20, 2004 #14

    matt grime

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    Hmm, no one says that the laws of relativity *make* things happen in a causal sense. The universe is as it is, and we can model it using a relativistic argument that fits lots of experimental data. It is a good model but doesn't take into account quantum effects, for instance. I don't think you've grasped that these are just models, theories, they do not cause things or dictate how the universe will behave, they predict a behaviour and a lot of the time the actual observed data fits the model but that isn't the same thing.
     
  16. Sep 28, 2004 #15
    I think thats a pretty glib thing to say, that hardly sweeps the subject
    under the carpet All your presenting is one of many ways it's possible to percieve time and saying that it need not be thought of any further.
     
  17. Sep 28, 2004 #16
    Someone made a statement earlier that that we move through time
    and that time flows. I disagree i think this is an absurdity, i think
    time is simply change, or the mechanism by which we allow
    change to be percieved. So in a sense, to say 'im flowing through time' is
    like saying 'im flowing through change' it makes no sense.
    But thats just my perception of it, probably no more valid that anyone
    elses.
    Yes id agree with that ; )
     
  18. Sep 28, 2004 #17
    where did you come across that? ive seen pages on the web dedicated to 11:11 and its meanings. Although im still pretty in the dark about it all myself.
     
  19. Sep 29, 2004 #18
    It makes sense in the relativistic sense. Someone moving at a similar speed to me appears to experience the same flow of time, the same rate of change as I do. Someone moving significantly faster or slower than me or in a high gravity well, seems to me to be experiencing a slower flow of time.
     
  20. Sep 29, 2004 #19

    chroot

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    This is incorrect. No matter how fast you move with respect to other objects, you will always observe your watch ticking at the same rate.

    - Warren
     
  21. Sep 29, 2004 #20
    You might want to read it again. What I observe is someone else's watch moving slower.
     
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