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Thread: spacetime contraction

  1. #1
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    spacetime contraction

    If I started accelerating towards a star starting at 0 mph relative to the star and accelerated to near the speed of light. Would I be able to detect the curvature of space time?

    Would I notice either myself or the star getting larger or smaller?

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    You would not notice anything about yourself changing, but you would notice the rest of the universe changing around you.

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    Quote Originally Posted by korjik View Post
    You would not notice anything about yourself changing, but you would notice the rest of the universe changing around you.
    So the star would BECOME ( not appear ) relative to me much bigger the faster I was moving towards it ( or away from it , or even perpendicular to it. )

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    Quote Originally Posted by tommac View Post
    So the star would BECOME ( not appear ) relative to me much bigger the faster I was moving towards it ( or away from it , or even perpendicular to it. )
    Actually, directly ahead and behind would only be blue- or red-shifted. You wouldnt see much, if any distortion.

    The distortion would be off to the sides. It is very hard to explain what would exactly happen, but things would look kinda rotated.

  5. #5
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    Your direction is as important as velocity is relative. The light image received from ahead of you would be intense and blue shifted noticeably. The opposite would be obvious from the rear view.

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    Does the contraction only happen in the direction of travel + in the dimension of time?

    So if I am moving near the speed of light along the x axis the x dimension would contract for me + the time dimension would also contract right?

    But Y and Z dimensions would not change?

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    The problem here is compounded by the aberration of light. The link shows visual representations of how your view of the universe changes as you approach the speed of light. The universe seems to bend around you, but this is purely an apparent effect of course.

    Underneath all that, this is happening. The link shows visually how length contracts from the point of view of both the ship and the universe around the ship (there are movies too!). The same thing happens for time.

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    Quote Originally Posted by speedfreek View Post
    The problem here is compounded by the aberration of light. The link shows visual representations of how your view of the universe changes as you approach the speed of light. The universe seems to bend around you, but this is purely an apparent effect of course.

    Underneath all that, this is happening. The link shows visually how length contracts from the point of view of both the ship and the universe around the ship (there are movies too!). The same thing happens for time.
    OK ... However this brings more questions to mind.
    Like right now things are moving away from us at faster than the speed of light ... that means that we are moving at the speed of light away from other things right? I have argued in the past that this is not possible but it seems that many people dont agree with me.

    So say near the edges of our visible universe ... arent we traveling at the speed of light with reference to that?

    Basically arent we moving at differnt speeds all at the same time depending what you are using as a refernce ?

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    Quote Originally Posted by tommac View Post
    OK ... However this brings more questions to mind.
    Like right now things are moving away from us at faster than the speed of light ... that means that we are moving at the speed of light away from other things right? I have argued in the past that this is not possible but it seems that many people dont agree with me.
    It is possible as long as you accept that none of those distant galaxies are actually moving through the universe at the speed of light - it is the expansion of the universe that causes their apparent speed of recession.


    So say near the edges of our visible universe ... arent we traveling at the speed of light with reference to that?
    Yes, this point in space (or whatever was here billion of years ago) will look to an observer at the edge of our observable universe as if it is receding from them at the speed of light or faster.


    Basically arent we moving at differnt speeds all at the same time depending what you are using as a refernce ?
    Yes indeed, except it is better to avoid using the term moving as it implies inertial movement. The spaces around everything (at the large scales) are increasing in size as time passes.

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    Quote Originally Posted by speedfreek View Post
    Yes indeed, except it is better to avoid using the term moving as it implies inertial movement. The spaces around everything (at the large scales) are increasing in size as time passes.
    So does conversely mean we are shrinking ( relative to space itself )?

  11. #11
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    There is no evidence to support that idea. We are not shrinking.
    Gravitationally bound systems are not seen to be expanding.
    Only the expansive void... that space between Galaxies is expanding.
    The greater the distance from us, the faster the apparent expansion.
    The very best cosmological minds are telling us this is how it is.
    Just because I think that sounds wrong, does not make it so.
    Remembering that this is all relative and our understanding will be further refined. Mark.

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