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File: 24-cell.gif (2.76 MB, 255x255)
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Does there exist a space-filling rhombic disphenoid?
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Maybe you should ask your mom about how my thrombic fills the space between her isotittie.
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>>16264456
No.
Source? Divine intuition
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Yes, any object is space filling.
What makes space filling curves special is that they're 1d, anything higher than 1d can obviously fill space by making it arbitrarily large.
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>>16266308
Wrong: https://mathworld.wolfram.com/Space-FillingPolyhedron.html
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>>16264456
Here's one in 4-dimensions.
disphenoidal 288-cell
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SAFE SPACE

https://www.youtube.com/watch?v=TBvPIAWB_t0
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>>16264466
>Telephasic Workshop
https://www.youtube.com/watch?v=he8fMUmxHOU
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It's huge
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>>16264456
Our math isn't advanced enough to answer this question
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>>16264466
Tesseracts have quadrilateral faces, moron
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>>16280310
Maybe it's a 4D icosahedron?
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>>16280327
I bumped this thread twice because I find it interesting, and nobody has made any interesting posts yet.
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>>16280595
https://en.wikipedia.org/wiki/24-cell
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>>16280327
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>>16282677
Ehm
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I'll just analyze the obvious way to try to do it: join edges of the same length together. In order for this to work, at each edge the angle between the two faces that meet there must be [math]2\pi/n[/math] for some [math]n \geq 3[/math]. So let's try to calculate the angles between the faces.

Line the x, y, and z axes up with the rotational axes of symmetry of the disphenoid, and let <a,b,c> be a normal vector to one of the faces. Then <a,-b,-c>, <-a,b,-c>, and <-a,-b,c> are normal vectors to the other faces. The possible angles between the normal vectors are [math]\cos^{-1}\left(\frac{a^2-b^2-c^2}{a^2+b^2+c^2}\right)[/math], [math]\cos^{-1}\left(\frac{-a^2+b^2-c^2}{a^2+b^2+c^2}\right)[/math], and [math]\cos^{-1}\left(\frac{-a^2-b^2+c^2}{a^2+b^2+c^2}\right)[/math], and the angles between the faces are the supplements of these angles. We obtain the result

[math]\cos(\alpha) + \cos(\beta) + \cos(\gamma) = 1[/math]

where [math]\alpha[/math], [math]\beta[/math], and [math]\gamma[/math] are the angles between faces, each of which occurs at two opposite edges.

Now we just search for angles of the form [math]2\pi/n[/math] ([math]n \geq 3[/math]) that satisfy this equation. There is exactly one solution,
[math]\cos(2\pi/4) + \cos(2\pi/6) + \cos(2\pi/6) = 1[/math].
But this would give us a tetragonal disphenoid rather than a rhombic one.

I don't know whether or not there might be a more clever way of doing it that bypasses this issue.
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>>16283261
So that's a no, then?
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>>16283717
No under the stated assumption. I would guess it's no in general, but I don't have a proof of that.



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