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Two dimensional plane equal absolute nothing

  1. May 16, 2016 #1
    Hi, as we know all objects must be three dimensional. If there is two dimensional "object" or "shape" in the universe, "it" will not look different from space or nothing as "it" is neither thick nor thin. Mathematicians calling "it" as a "surface" but "it" have zero thickness, isn't it a contradiction to call that which has no thickness as a surface? Not to mention that two dimensional plane is extended infinitely inplying that "it" don't have shape. So, if "it" extended infinitely and have zero thickness "it" is just the same as nothing (that which has no shape) and "it" can only be assumed to "exist" in abstraction only. Any thoughts?
  2. jcsd
  3. May 16, 2016 #2


    Staff: Mentor

    There is a difference between physical reality and the mathematical or geometric objects we use to model reality.
    No. By your same logic, a line in space is an abstract geometric entity that extends infinitely far in two directions, and has zero thickness and zero width, but it's not the same as "nothing." Similarly, a point has zero width, zero length, and zero depth, but it is also not the same as "nothing."
    Surfaces, including planes, lines, curves, and points are all mathematical abstractions that we use to help us understand physical reality. But so what?
  4. May 16, 2016 #3
    No, it is the definition of a surface in the sense under consideration. That is part of what a surface is.

    Not all surfaces extend to infinity. For example, a spherical shell is a surface. But even if all surfaces "extended to infinity" that would not show that they are the same thing as nothing. "Nothing" has no properties, but a surface does have properties. Therefore a surface is not the same thing as "nothing."
  5. May 16, 2016 #4


    Staff: Mentor

    I'm a sailor. I live on the surface of the sea. Believe me, it really exists.
  6. May 16, 2016 #5
    Graphene is carbon atoms in a 2-D arrangement. While the atoms have thickness, they are arranged on a plane without thickness. Even if the plane is curved, it is still distinctly different from a 3-D arrangement of carbon atoms. Therefore, 2-D objects exist and have values that are not equal to zero or nothing.

    But if you're stuck on atoms having thickness, can you imagine a 2-D plane of electrons? Or some smaller thing that effectively has no size?
  7. May 16, 2016 #6
    What distinguish them from nothing if assuming there are 1D lines and 2D planes in existence? Can you explain how and why?
  8. May 16, 2016 #7
    In mathematics, perhaps we can say a 2D plane have properties but assuming if there is a real 2D plane in existence. What exactly distinguish a "surface" that is neither thick nor thin and infinitely extended in all directions from nothing such as space?
  9. May 16, 2016 #8
    If atoms themselves are 3D then 2D plane is impossible in existence.

    What are exactly the differences between 2D plane, 0D point and space or nothing in reality?
  10. May 16, 2016 #9
    Exactly. You asked if there was a contradiction. The answer to that question is no, because we are talking about definitions when we are talking about mathematics.

    That is a different question. I am inclined to think there are no real examples of 2D plane things beyond items of convention. We talk about such items as the orbital plane of our planet or the plane containing the equator (or the equator itself), but they don't exist as tangible things out in the real world.
  11. May 17, 2016 #10
    @Mohd Abdullah
    You are confusing the mathematical definitions with the physical concepts, as mentioned.
    All mathematical objects are abstractions and they don't "exist" the same way real objects "exist".
    It does not mean that abstract concepts are "nothing".
    The number 1000 does not "exist" as a physical object but is it "nothing"?

    What we call 2D and 1D objects in physics is not the same as the abstract notions of planes and lines in mathematics.
    There is no point to argue about them.
    The "surface" of a solid, as studied by "surface science" is a completely different object than the mathematical notion of surface.
    Same as a ball is not a mathematical sphere even though we may use the math concept to model the real object.
  12. May 17, 2016 #11
    That's my point. In reality or existence, real 2d "shape" or "object" is impossible. Thus, if there is a 2d or 0d "shape" or "object" in reality "it" will not look different from nothing. Real objects and concrete shapes (not abstract) are necessarily 3D.
    Last edited: May 17, 2016
  13. May 17, 2016 #12
    What we call as 2d or 1d "object" or "shape" in physics is too, impossible in existence. Just like the mathematical abstract notions of planes and lines. Even if 2D, 1D or 0D "shape" or "object" is possible in existence, what is the difference between them and space or nothing? All objects, real objects and concrete shape, are necessarily 3D unless someone makes an abstract "shape" in his or her mind.
  14. May 17, 2016 #13
    How can be existing objects impossible?
    Graphene sheets, nano-wires, quantum dots - they all exist and are very possible. It's just that associating these real structures with 2D or 1D models does not make them abstract mathematical objects.
    You won't say that the 100 dollar bill in your pocket is "impossible" just because the number 100 is an abstract concept which is impossible "to exist".
  15. May 17, 2016 #14
    Graphene sheets and nanowires are actually 3D, as it is formed by atoms which are necessarily 3D and still have a very small amount of thickness. A real 2D "shape" in reality will have no any difference from nothing, as "it" is neither thick nor thin and "it" have zero thickness. Not to mention "it" will have no extended dimensions in existence. About the quantum dots, I'm not sure about "it" as "it" keep popping out from nothing and then disappear again into nothing. I think we need to define the word "exist" unambiguously.
  16. May 17, 2016 #15
    And this is just what I was trying to say in the last two posts. They are modeled as 2D but they are not a mathematical surface, not an actual 2D object in the sense of the mathematical definition.
    So the discussion has no point. Arguing about existence or not of abstract mathematical concept is pointless. They have the same level of "existence" as all abstractions.
    And there is no relevance for the existence of the objects modeled by these abstractions.
  17. May 17, 2016 #16
    Mohd: If you want to think of surfaces and points as being nothing, that's up to you. But, to the rest of us, they have much more meaning than that.
  18. May 17, 2016 #17
    Points, lines, surfaces and volumes - all define places … and none of them are concrete (i.e. real, and not abstract) things.

    So, if your definition of a 'thing' is that it has mass and is made of stuff, then you're right, a surface is no-thing. Note, however, that in the physical universe, all things (that are made of stuff and have mass) have a place, an edge (bounding surface) and a volume (but it would be untrue to say that they are their place, edges or volume).

    A volume, on the other hand - is just the place where stuff exists, and a surface is just the place where one thing stops and another starts (such as the surface of the ocean, as another person remarked).

    A surface is clearly a place of transition - and can never be a physical thing in its own right.
    Last edited: May 17, 2016
  19. May 17, 2016 #18
    In maths I can be anything.
  20. May 23, 2016 #19
    I define thing, or object, as that which has shape. But it seems a 2D plane can be interpreted as an object and not as an object in mathematics. 2D plane is generally defined as having two extension or someone can call the extensions as width and length (width is just length if someone see it from another orientation) and is not thin and thick (zero thickness). This 2D plane also extend into infinity, so this definition fall within the category of nothing while if someone define 2D such as abstract shapes like triangle and square then it fall within the category of object.
  21. May 23, 2016 #20
    Sorry what do you mean by that?
  22. May 23, 2016 #21
    I think he meant in a humorous way that math produces results which depends on what assumption are made.
    Math is not a problem, but assumptions can be.
  23. May 24, 2016 #22
    Well for example;

    I can make a logically sound argument that is complete nonsense.

    I can be a perfect circle in math that can't be in reality.

    I can also divide by zero.
  24. May 24, 2016 #23


    User Avatar
    Science Advisor

    Thing can mean different things.
  25. May 24, 2016 #24
    Which thing, some thing, any thing or every thing?
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