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What effect would complete stillness have on Time?

  • 15-09-2011 9:45am
    #1
    Registered Users, Registered Users 2 Posts: 636 ✭✭✭


    It's pretty well documented what happens with time to objects as they go faster, and we've even got examples of it with GPS systems here on earth. But what if anything happens if a body of mass were to be completely still? Is it the reverse of an object approaching the speed of light, or is it just a time difference marginally off where we are on earth? If the effect of stillness is nothing unusual what is the time difference between a completely still body of mass and time here on earth?

    Another slightly unrelated thought. Maybe I'm mistaken but just thinking about it it seems like getting a body to be completely still within the universe is a very difficult thing to achieve maybe even impossible? If it is possible how could it be proven that it were completely still?


Comments

  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 93,604 Mod ✭✭✭✭Capt'n Midnight


    Time is relative. Objects that don't move relative to you are in the same time frame and age as fast as you do. Objects moving relative to you will age slower. And to them you will appear to age slower than they do.

    Time is also affected by gravity.


    It's very difficult to determine if an object is still, in fact it's very difficult to determine the centre of the universe since if you extrapolate backwards in time every point arrives at the big bang singularity.

    At the equator the earth rotates at 1000 Knots , here is it very roughly 1,000km/hr. The earth orbits the sun and the sun rotates around the centre of the galaxy (which is moving around the Andromeda cluster ??) etc.


  • Registered Users, Registered Users 2 Posts: 2,781 ✭✭✭amen


    And to them you will appear to age slower than they do.

    If they are moving relative to you then you should appear to age faster.
    If the effect of stillness is nothing unusual what is the time difference between a completely still body of mass and time here on earth?

    being still or will not impact the speed at which you go old.

    If you are on the earth you will take 1 earth year* to become one year older.

    If you are traveling at the speed of light you will take 1 earth year* to become one year older but due to the speed you are traveling relative to someone on earth it will seem that you take may thousands of earth years to age.



    * 1 earth year defined as 1 SI second X 31536000 seconds in a year


  • Registered Users, Registered Users 2 Posts: 636 ✭✭✭pug_


    Thanks for the replies. Maybe I should rephrase the question. Relatively speaking, how much faster would we appear to age than a person who is completely still in the universe?

    Also given the fact that the universe its self is expanding is it even possible to achieve complete stillness? i.e. does an expanding universe make your position within the universe change regardless of what you do.

    Finally, assuming it is possible to achieve complete stillness, is it even possible to accurately tell if something is completely still within the universe in the first place? The reason I'm wondering this is the only way I know to test for velocity is to measure it from a fixed point, of course in our case fixed is relative because we're hurtling around the sun, which is spiralling around the galaxy, which is also speeding on it's own course within a universe that is expanding. So from my understanding at least if you believed you were completely still the only way you would have of gauging it is relative to other objects which are not stationary. It's more of a practically speaking how would it be done kind of question.


  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 93,604 Mod ✭✭✭✭Capt'n Midnight


    pug_ wrote: »
    The reason I'm wondering this is the only way I know to test for velocity is to measure it from a fixed point,
    you could also look at spinning

    think of the way you can simulate gravity by spinning a spacecraft or carnival ride. can you use several of these at right angles to each other to determine a point fixed in space ?


  • Registered Users, Registered Users 2 Posts: 2,781 ✭✭✭amen


    Relatively speaking, how much faster would we appear to age than a person who is completely still in the universe?

    well it depends on how fast you are going relative the person who is still.

    If you are moving at just a few thousand of miles an hour not much.

    At the speed of light could be several hundred years.

    Its all relative.
    think of the way you can simulate gravity by spinning a spacecraft or carnival ride. can you use several of these at right angles to each other to determine a point fixed in space ?
    but you are still moving all you are doing is cancelling out the effects of gravity.

    I think the op is considering someone at the center of the universe with everything revolving around him


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  • Registered Users, Registered Users 2 Posts: 636 ✭✭✭pug_


    you could also look at spinning

    think of the way you can simulate gravity by spinning a spacecraft or carnival ride. can you use several of these at right angles to each other to determine a point fixed in space ?
    I don't know can you? If you had 8 objects all equidistant to each other and all spinning how would you know if collectively all 8 were not travelling with a certain velocity in a certain direction? Unless I'm not understanding the context properly :)
    amen wrote: »
    well it depends on how fast you are going relative the person who is still.

    If you are moving at just a few thousand of miles an hour not much.

    At the speed of light could be several hundred years.

    Its all relative.
    And to us here on earth what's that difference? Is it measurable, or is it even a meaningful question?

    I thought a little more about it earlier on today and maybe if everything is relative then from the perspective of the universe the notion of absolute stillness doesn't make sense at all. For something to be still within the universe would the universe not need to be a definite predefined 3d shape? i.e. if you put a marble into a cube and suspended it in the one spot you would know it's still within the confines of the cube because you can see it's not moving in any direction relative to the sides of the cube. But from what I understand the universe doesn't have any defining edges to benchmark against making the notion of absolute stillness (not relatively speaking, but absolutely) an impossibility. Leaving stillness relative to all observable objects as the only meaningful definition of stillness.

    I'm a little drunk at the moment so there is a high likelihood that the above makes absolutely no sense, but it makes sense to me at the moment anyway :D


  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 93,604 Mod ✭✭✭✭Capt'n Midnight


    pug_ wrote: »
    And to us here on earth what's that difference? Is it measurable, or is it even a meaningful question?
    yes

    atomic clocks and GPS satellites show effects due to movement AND gravity

    http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System
    we need to slow the clocks down from 10.23 MHz to 10.22999999543 MHz in order to negate the effects of relativity.

    So you need to slow the clock down to .999 999 999 55 times it's original speed when you travel at 13,946 km/hr (+/-)

    it's meaningful in the sense that GPS positions would be out by tens of meters if you forget that relative motion of the satellite will also affect the time delays as they will at first be heading towards you and later away from you


  • Registered Users, Registered Users 2 Posts: 636 ✭✭✭pug_


    yes

    atomic clocks and GPS satellites show effects due to movement AND gravity

    http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System

    So you need to slow the clock down to .999 999 999 55 times it's original speed when you travel at 13,946 km/hr (+/-)

    it's meaningful in the sense that GPS positions would be out by tens of meters if you forget that relative motion of the satellite will also affect the time delays as they will at first be heading towards you and later away from you
    Yup, but as I understand it that's only meaningful for calculations relative to the earth.

    What I'm trying to understand is absolute stillness within the universe (not stillness relative to any other objects within the universe, only a stillness that is universal). Is it real or measurable? If it is real what is the relative time difference between something that is absolutely still, and a person here on earth?


  • Moderators, Science, Health & Environment Moderators Posts: 3,645 Mod ✭✭✭✭Beeker


    pug_ wrote: »
    Yup, but as I understand it that's only meaningful for calculations relative to the earth.

    What I'm trying to understand is absolute stillness within the universe (not stillness relative to any other objects within the universe, only a stillness that is universal). Is it real or measurable? If it is real what is the relative time difference between something that is absolutely still, and a person here on earth?
    I don't think the concept of absolute stillness exists unless it is measured against something else.


  • Registered Users, Registered Users 2 Posts: 785 ✭✭✭ILikeBananas


    pug_ wrote: »
    What I'm trying to understand is absolute stillness within the universe (not stillness relative to any other objects within the universe, only a stillness that is universal). Is it real or measurable? If it is real what is the relative time difference between something that is absolutely still, and a person here on earth?

    I've just begun reading "Why does E=mc2" by Cox & Forshaw and this topic is covered in the first chapter.

    To answer your question. Absolute Stillness is impossible within the Universe because this would imply absolute position, which doesn't exist. This concept was first put forward by Galileo and was one of the major breakthroughs in astrophysics.


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  • Registered Users, Registered Users 2 Posts: 636 ✭✭✭pug_


    I've just begun reading "Why does E=mc2" by Cox & Forshaw and this topic is covered in the first chapter.

    To answer your question. Absolute Stillness is impossible within the Universe because this would imply absolute position, which doesn't exist. This concept was first put forward by Galileo and was one of the major breakthroughs in astrophysics.

    Excellent, that is exactly what I wanted to know. Many thanks :)

    Is that book any good by the way? It sounds like the type of book I'd enjoy.


  • Registered Users, Registered Users 2 Posts: 785 ✭✭✭ILikeBananas


    pug_ wrote: »
    Excellent, that is exactly what I wanted to know. Many thanks :)

    Is that book any good by the way? It sounds like the type of book I'd enjoy.

    You're welcome. I've only read three chapters but so far so good. It aims to explain all of the concepts leading up to Einsteins special theory of relativity. It claims to do this without using any mathematics more complicated than Pythagoras's equation, so as you can imagine there are a lot of analogies used instead.


  • Registered Users, Registered Users 2 Posts: 128 ✭✭Allosaur


    Hang on... isn't movement like time, relative?
    Hence without a frame of reference, then all objects can just as easily be said to be at rest....


  • Registered Users, Registered Users 2 Posts: 8,551 ✭✭✭Rubecula


    you could also look at spinning

    think of the way you can simulate gravity by spinning a spacecraft or carnival ride. can you use several of these at right angles to each other to determine a point fixed in space ?

    Sorry for the belated reply but I have only just seen the thread.

    What you are describing is a Space Gyro, it is used for navigation in all three dimensions amongst other things. (Or at least it was, more modern methods now exist.)


  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 93,604 Mod ✭✭✭✭Capt'n Midnight


    Rubecula wrote: »
    What you are describing is a Space Gyro,
    But could the OP use it to define a point in space that is static ?

    Bearing in mind that our solar system is rotating around a galaxy which is heading towards Andromeda.


  • Registered Users, Registered Users 2 Posts: 8,551 ✭✭✭Rubecula


    I don't know the answer to that one, but there must be something about a gyro (a space gyro anyway) as it will ALWAYS point at the same place while it is running.

    Maybe there is a detectable something out there, but if there is I have no clue as to what it may be.

    As for pointing at a spot that is totally stationary, that is entirely different. The only totally staionary place in the entire universe is the exact centre where the big bang occured. and guess what, the entire universe was there so that makes it all totally stationary. Just not with respect to anything else that exists.

    I think I need me tablets.:pac:


  • Registered Users, Registered Users 2 Posts: 128 ✭✭Allosaur


    We're in danger of thinking in terms of newtonian physics to describe something quantum physics still has issues with. Put it like this:

    The "Big Bang" at the start of our expanding universe happened everywhere. Secondly due to the infinate nature of the universe there can be no center, or rather every part of the universe is as much the center as any other point.

    Rube, time to up the meds here too....


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