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Can anyone tell a good quotation about GR?

  1. Sep 20, 2010 #1
    Which is not homourous but philosophical.
  2. jcsd
  3. Sep 20, 2010 #2


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    This is probably not an exact quote. I wasn't able to find the original source.

    "Spacetime tells matter how to move. Matter tells spacetime how to curve." (John Wheeler).

    Is that the sort of thing you had in mind?
  4. Sep 20, 2010 #3
  5. Sep 20, 2010 #4
    "Spacetime tells matter how to move. Matter tells spacetime how to curve." (John Wheeler).

    This is too trivial and evident.

    Something else?
  6. Sep 20, 2010 #5
    When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.
  7. Sep 20, 2010 #6
    The scientists often have more unfettered imaginations than current philosophers do. Relativity theory came as a complete surprise to philosophers, and so did quantum mechanics, and so did other things.
  8. Sep 20, 2010 #7


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    Seriously? It summarizes the content of the theory in two short sentences, and is probably the most famous quote in physics. Why do you want quotes anyway? What sort of people are you going to show them to?
  9. Sep 20, 2010 #8
    Ah yes, didn't Shakespeare say "There are more things in time and space, Horatio, than are dreamt of in your philosophy"

    Hmmm.. maybe that is not quite right. :tongue:
  10. Sep 20, 2010 #9
    I think the quote should have been "There are more things in set theory, Horatio, than are dreamt in your philosophy."
  11. Sep 20, 2010 #10
    "Everything is relative" is a popular saying that usually applies to SR but could be applied to GR. In SR the saying has limitations, because some things like the speed of light are actually absolute. However, we can elaborate a little and maybe say something like, when two observers disagree on the measurement of some quantity, then there is no way to determine who's measurement is more "real". In SR, rotation measured using a Sagnac device appears to be absolute. In GR, rotation initially appears to be absolute. A planet rotating in empty space appears to bulge at its equator and this bulge is attributed to "absolute" rotation of the planet. However, imagine you had a satellite in geosynchronous orbit about the planet. From the satellite, the planet appears to be stationary. You could say that from the satellite's point of view, space-time is rotating about the planet and the "rotating space-time" is causing the planet to bulge and also preventing the satellite falling straight towards the planet. This is not the usual way of depicting things, but it not possible to prove that this is not what is happening. Closer to home, we can not prove the Earth is not the centre of the universe and that everything does not revolve around the Earth, but we can show that we can pick any planet or star and the same would be true. If your reason for looking for quotes is to form the introduction to a philosophical discussion of GR maybe this a place to start along with the place of Mach's principle in the philosophy of GR. Certainly an analysis of what is "real" and what is not, in GR will take you into some deep philosophical discussions about GR.
  12. Sep 21, 2010 #11
    This is about relativity and not GR.
    And this is homourous and not philosophical.
  13. Sep 21, 2010 #12
    But this is a kind of mathematical definition, not a quote. No human factor. Its just a simple definition.
  14. Sep 21, 2010 #13


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    ..... you do know what the 'R' stands for right?
  15. Sep 21, 2010 #14
    When asked to sum up his theory of relativity in one sentence, Einstein said: "Time and space and gravitation have no separate existence from matter...Physical objects are not in space, but these objects are spatially extended."
  16. Sep 23, 2010 #15
    When I said quotation "about" GR, this means not necessary a definition (what is GR) what I need.
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