I Does a 2-dimensional world really exist?

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The discussion centers on the concept of dimensions, specifically questioning the existence of true two-dimensional (2D) space. It explores how higher-dimensional beings might interact with lower-dimensional beings, using the example of a sphere moving through a 2D world. The idea that a line or dot could exist without height raises philosophical and mathematical questions about the nature of dimensions. While some argue that 2D is a useful mathematical abstraction, others suggest it may not exist in reality. Ultimately, the conversation highlights the distinction between theoretical constructs and their practical implications in understanding dimensions.
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When we try to explain different dimensions we say that higher dimension beings have control over lower dimension beings. If a sphere moves trough a 2D world, the 2D beings will see a dot appear followed by a line which is increasing in size. Thereafter, the line decreases in size and becomes a dot again before it disappears completely.

However, when you think of a line you always think of a certain amount of height. A line without any form of height seams to me like it would be invisible. Even a piece of paper has height, even the graphite from the pencil which you draw with has a certain 3D trail on top of the paper.

When I imagine a 2D world, I imagine a very narrow horizontal area 360° around me in which I can see. It is however still an area with a height. So my question, does actual 2D exist? How can you have a line or a dot with no height?
 
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A two-dimensional space exists as a mathematical construct which can be useful in modelling systems found in the real world. However the world we live in is (as far as we know) three dimensional.
 
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Lars1408 said:
So my question, does actual 2D exist?
One surface of a piece of paper is 2d. That, of course, is a mathematical abstraction. Whether it "really exists" or not is less important than whether the concept is useful.
Lars1408 said:
When we try to explain different dimensions we say that higher dimension beings have control over lower dimension beings.
Do we? I guess you've been reading Edwin Abbott's Flatland. Do remember that it's a satire on English social attitudes as well as a fun description of some different dimensional manifolds. Don't take it too literally.
 
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Ibix said:
One surface of a piece of paper is 2d. That, of course, is a mathematical abstraction. Whether it "really exists" or not is less important than whether the concept is useful.

Do we? I guess you've been reading Edwin Abbott's Flatland. Do remember that it's a satire on English social attitudes as well as a fun description of some different dimensional manifolds. Don't take it too literally.

With the second quote I mean that we could be above a 2D space withouth the 2D space ever knowing about this. IF a 2D world does exist it would make sense that they could only percieve the plane they are in.
 
Lars1408 said:
With the second quote I mean that we could be above a 2D space withouth the 2D space ever knowing about this. IF a 2D world does exist it would make sense that they could only percieve the plane they are in.

This is just a science fiction concept, science has nothing to say about this.
 
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HomogenousCow said:
This is just a science fiction concept, science has nothing to say about this.
I think that's the perfect note on which to close this thread.

@Lars1408, have you read the classic "Flatland" by Edwin Abbott? (Just for fun.)
 
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