Blog: The Fascinating Possibilities of 2D Objects in a 3D Universe

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Discussion Overview

The discussion explores the concept of dimensionality, specifically how 2D objects might exist within a 3D universe and the implications of higher dimensions, including the fourth dimension and beyond. It touches on theoretical physics, mathematical models, and the nature of perception in relation to dimensionality.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions how 2D objects can exist in a 3D world, arguing that if all matter is 3D, then the concept of a 4D world surrounding our universe is problematic.
  • Another participant suggests that a 2D object, like a sheet of paper, can appear 3D from certain angles, highlighting the complexity of perceiving dimensions and the nature of time as a fourth dimension.
  • A different participant expresses confusion regarding the nature of 1D strings in string theory, questioning how they can exist without width while still having length and the implications of their existence at the Planck length scale.

Areas of Agreement / Disagreement

Participants express differing views on the existence and perception of dimensionality, with no consensus reached on the nature of 2D and 3D objects or the implications of higher dimensions.

Contextual Notes

Participants note limitations in understanding the nature of dimensions, particularly regarding the perception of thickness in 2D objects and the complexities of string theory, without resolving these issues.

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How is it possible for a 2 dimensional object to exist in a 3 dimensional world? Even the atoms that make up everything in the universe are 3D. This being the case how can we say that our 3D universe is surrounded by a 4D world we cannot see? I guess what I am saying is if 2D objects can't exist in 3D than how can 3D objects, like our universe, exist in a 4D?

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If you'd take something (like a sheet of paper) and looked at it from a 90° angle, you wouldn't be able to see that it's actually 3-dimensional, would you? Especially if you didn't have any control at all over it's motion in the third dimension it would be very hard to detect that it actually has a thickness.

The "fourth dimension" usually used in physics, time, is a rather tricky one anyway. According to our mathematical theories, it is very much "the same" as our spatial dimensions, yet our intuition tells us completely the opposite. For one, we are moving through time at a constant velocity (well, through space-time at least) so we have hardly any control about where we go in this dimension.

If you want to talk about string theory with > 9 dimensions, it becomes an even more complicated story so let me not go there ;)
 
I don't really follow the answer. It might appear as 2d yes, but he even mentioned the atomic level. You can have an object appear as 2d or a point like particle but the closer you get you eventually see that it is does have thickness. Speaking of strings that is something I don't get, how can a 1D string exist if it has length but no width or other dimensions? I know it can vibrate in 3 dimensional space (as well as calabi yau space or whatever other sets of spatial dimension configurations that might exist) but I still can't picture on the Planck length scale viewing the string I'd think it would appear as invisible if it truly had zero thickness.
 
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