What is the difference between SR and GR?

Discussion in 'General Science & Technology' started by Mark Turner, Jul 5, 2019.

  1. Mark Turner Registered Senior Member

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    As per title question

    Thanks in advance .
     
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  3. Seattle Valued Senior Member

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    The curvature of space/time caused by gravity.
     
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  5. mathman Valued Senior Member

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    S.R. is about systems without acceleration. G.R. includes affects of acceleration, including gravity.
     
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  7. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    in agreement with mathman, though possibly more simply put,

    SR entails movement, and how different observers perceive time is dependent upon the relative velocity of those observers.

    GR concerns Gravity, and the effects of mass on space and time.

    to put it simply,
     
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  8. Mark Turner Registered Senior Member

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    Thank you for your reply and likewise to other posters .

    Is what you mention about observers perceiving time , SR , the time dilation part of relativity ?

    Thanks in advance
     
  9. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    Probably a good bit over-simplified, but yes.

    An Internet Forum is not the best place to get educated, if you really want to learn about SR and GR, though.
     
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  10. Mark Turner Registered Senior Member

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    Thank you for your reply .

    I'd of thought a science forum would be the perfect place to learn , yourselves have been answering my questions !

    I do have some basic knowledge of physics but SR and GR is quite confusing , almost imperceivable .

    When time slows down , is it possible to reverse time flipping the direction of time ?

    Thanks in advance.
     
  11. Neddy Bate Valued Senior Member

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    Actually, as long as there is no gravity, you can use SR. So SR can be used even in cases with coordinate acceleration. You just have to know how to do it, and be careful.
     
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  12. paddoboy Valued Senior Member

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    It could be said that SR is just a special case of GR.
     
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  13. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    The simplest answer that I can provide for you is No.

    I'll let the "experts and knowledgeable" answer any further questions that you have.

    Welcome to Sciforums.
     
    Last edited: Jul 6, 2019
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  14. paddoboy Valued Senior Member

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    The thing with science forums, like any public forum, they are open to any Tom, Dick or Harry. The trick is to sort the wheat from the chaff, or the experts and knowledgable from the nonsense. I'm only [probably like yourself, an amateur] and have learnt plenty from forums like this, supplemented with reputable reading of the likes of Sagan, Weinburg, Thorne, Rees.

    I'm not sure I understand your "flipping time" question properly, but two important issues to remember are [1] All Frames of references, are equally valid and real, and [2] each frame always sees time pass at 1 second per second within his own frame.
     
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  15. paddoboy Valued Senior Member

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    Hmmm, can I tidy that up some?
    The curvature/warping of spacetime is caused by matter/energy, and we see that effect as gravity.

    Please Register or Log in to view the hidden image!

     
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  16. paddoboy Valued Senior Member

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    Yes...example: If you and I were approaching a BH, and me being far more intrepid then you, decided to have a look inside, while you observed at a safe distance......You would observe me approaching the EH, but gradually being continually red shifted until beyond the capabilities of your on board scopes and I would just fade from view from your perspective.We call that gravitational time dilation and gravitational redshift. From my position, I would continue on merrily and cross the EH and fall towards the center, eventually being torn asunder depending on the BH's size...a large SMBH, the tidal effects would not be felt right away...with a stellar size BH, I could invariably be torn asunder even before I crossed the EH. https://jila.colorado.edu/~ajsh/
     
  17. Seattle Valued Senior Member

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    How about I tidy that up some as well? The curvature/warping of spacetime is caused by the effect that gravity has on matter.
     
  18. DaveC426913 Valued Senior Member

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    Good catch.

    Curvature of spacetime is not caused by gravity. Curvature spacetime is gravity.
     
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  19. paddoboy Valued Senior Member

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    Not really...see Dave's reply
     
  20. Mark Turner Registered Senior Member

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    I am only an enthusiast , I'd rather have the answers given than try to give answers .

    If in different frames of reference both measure 1 second per second , who is correct ?

    Thanks in advance .
     
  21. Mark Turner Registered Senior Member

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    Are you saying spacetime is more than xyzt ?

    Thanks in advance .
     
  22. paddoboy Valued Senior Member

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    Both are equally correct in there own frame.
    https://www.khanacademy.org/science...ocity-time/v/introduction-to-reference-frames
    https://www.khanacademy.org/science...on/v/finding-an-in-between-frame-of-reference
    https://www.khanacademy.org/science...ocity-time/v/introduction-to-reference-frames
     
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  23. Mark Turner Registered Senior Member

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    Alright , thank you for your reply .

    I'm starting to understand SR better now .

    I understand from all of the given answers ;

    Time can be measured at difference rates but each observer measures 1 second per second relative to their reference frame .

    Is that correct ?

    Thanks in advance .
     

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