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B Is the Universe a 3D Cut of a 4D object?

  1. Sep 3, 2018 #1
    I have just simple Knowledge, but recently a question came To my mind.
    An Entity Living in 2d Space cannot Directly Observe a sphere, but rather a Circle Changing its Size when a sphere is traversing trough the observable 2d plane.
    Similar, a 4d sphere would Appear To us as 3d sphere Changing its Size when traversing trough our observable 3d Space.
    What if Spacetime is a 4d sphere that we Observe as 3d Ball, but we are obviously Inside. Wouldnt it be Logical, that the Expansion of Space is just the geometrical property of this traversal?
     
  2. jcsd
  3. Sep 3, 2018 #2

    phinds

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    that topic has been discussed here MANY times. I suggest a forum search.
     
  4. Sep 3, 2018 #3
    Sorry, maybe Not able To find it due To Language issues - any Tipps or Links? Thank you
     
  5. Sep 3, 2018 #4

    phinds

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  6. Sep 4, 2018 #5
    Thank you. From the threads i was reading, I am not convinced how things work out here (what again was confirmed by the link you sent). There are some users that neglect many threads in the first place. Science is not "having evidence or references", this is hen egg thinking. Science is discussing potential realities, and elaborating experiments to test hypotheses about such realitites - i know that, because this is how i earn my money.
    However, I clearly understand that its neither a funny job or duty to explain things over and over again to new users that have no clue in the first place. But in what you sent me, the topic has not been "discussed". It was just neglected.
     
  7. Sep 4, 2018 #6

    phinds

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    You misunderstand the raison d'etre of the Physics Forum and possibly have either not read, or not understood, the rules you agreed to when you joined. Science does indeed, as you say, include discussing potential realities, and there are forums where that discussion can be carried on but this is not one of them. PF is for established science, as it states clearly in the rules. If there were evidence of your hypothesis, and there were papers discussing that evidence, then it would be a solid topic for PF. When you can cite such papers, please do. I for one would be very interested in hearing that this hypothesis has an evidentiary basis. Until then, it is just personal speculation and not the kind of established science discussed on PF.
     
    Last edited: Sep 4, 2018
  8. Sep 4, 2018 #7

    anorlunda

    Staff: Mentor

    I like it the way @phinds explained it in another thread.

    To that, I would add, "PF is the place to learn what is in the box."
     
  9. Sep 4, 2018 #8

    Dale

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    The universe is a 4D object. (No cut is physical)
     
  10. Sep 4, 2018 #9

    Delta²

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    According to some variations of string theory I have heard (but not have studied myself) the universe is a 25D object. But string theory is just a very beautiful theory that explains everything but for which no experimental evidence are available. No one has make some sort of experiment to verify the existence of strings, neither some sort of device that can sense any of the 5th and higher up to 25th dimension.
     
  11. Sep 4, 2018 #10
    There is established work that the universe is 2D similar to a hologram. Here is a discussion on the subject with some noteworthy participants. You may find some interesting new insights to help you with your investigations.

     
  12. Sep 9, 2018 #11

    phinds

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    The fact that one can create a mathematical construct showing that the information in a 3D sphere can be contained in an area that is the surface area of the sphere is irrelevant to the actual workings of the universe. That is what is indicated by your use of the necessary phrase "similar to", so it's an interesting mathematical curiosity but is, I believe, NOT actually helpful in determining whether the universe is a "cut" of a higher dimension (it's not but the Holographic Principle isn't going to help prove that one way or the other).
     
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