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Are dimensions needed because of Infinity?

TiredThinker July 28, 2022 at 23:06 1650 views 6 comments
If there were a finite number of things on 3 axises, could that same information be represented in a single line? Do higher dimensions exist only for when values go on forever in an axis?

Comments (6)

jgill July 28, 2022 at 23:20 #723266
If its any help, the "number" of points inside a cube is the same as found on one of its defining edges (lines).
TiredThinker July 29, 2022 at 01:16 #723301
Reply to jgill

I don't mean number of points in a math object. Lets say miles or representation of number of countable things.
Pie July 29, 2022 at 08:04 #723411
Quoting TiredThinker
If there were a finite number of things on 3 axises, could that same information be represented in a single line? Do higher dimensions exist only for when values go on forever in an axis?


It sounds like you'd want an invertible function [math]f : S \subset \mathbb{R}^3 \to\mathbb{R} [/math], with [math]S[/math] finite. That should be easy (an infinity of choices.) One boring but easy approach is ordering the points in the domain set ('alphabetically') and just counting them off like [math] 0 ,1, ... , n - 1 [/math].

I think what you are really interested in is bases for vector spaces.
https://en.wikipedia.org/wiki/Basis_(linear_algebra)


alan1000 July 29, 2022 at 14:27 #723524
"If there were a finite number of things on 3 axises, could that same information be represented in a single line?"

Yes indeed. You might read up on Georg Cantor, who did a lot of work in this area.
alan1000 July 29, 2022 at 14:31 #723526
"If its any help, the "number" of points inside a cube is the same as found on one of its defining edges (lines)."

Can you develop that a bit further? Points in any continuum are infinitely many.
jgill July 29, 2022 at 19:35 #723576
Reply to alan1000 There's a one to one correspondence between points on such a line and points in the interior of the cube. You could look it up, it's a simple arithmetic trick involving manipulating the digits of the numbers representing the points.