3 ms·
I'd really love to know if this has any (remote, or even indirect) connection to the very special & cool irrational (one might say 'magic') angles described in
by no_identd 7y ago
I'd really love to know if this has any (remote, or even indirect) connection to the very special & cool irrational (one might say 'magic') angles described in this (Open Access, HTML!) paper:
https://link.springer.com/article/10.1007/s00004-015-0285-1 https://link.springer.com/article/10.1007/s00004-015-0285-1
Vanderroost, Mike - Morphic Angles (2016)
I wanna know this, among other reasons, because no other paper cites this one, nor does any other paper describe these angles, yet, when one plugs the closest IEEE single/double float numeric approximation of the absolute numeric value of these angles into Google Scholar (in quotes), one can find numerous, but not staggeringly numerous, occurrences of these in the mathematics, physics, & biology literature.
All of these seem to so far have gone unidentified as linked to the rather generalized constructions from the above paper, because the obviousness of how to derive it seems somewhat unidirectional. I'd explain what I mean by that more specifically, but I actually struggle rather hard with finding the right words for it, so, for now I can only suggest trying it out yourself and seeing what you find!
I'll give you the IEEE float approximations I have at hand, which only cover the 2D case derived from the golden ratio, and not the 3D case derived from the plastic number (personally, I'd prefer if we started calling it the radiant ratio, but I don't think that'll catch on). Note that I don't have have single and double float values for them at hand right now, and that if one wanted to thoroughly check the literature for unnoticed occurrences of this, one'd have to factor in:
1. the two possible representations of each type of float. I forgot the term, but, the 'short' version typically returned by most but not all software, and the 'long' version actually stored, which /some/ software actually outputs. Both get accepted as the same value, of course)
2. each form of float rounding behavior
Anyway, here:
golden morphic angles (see the paper for why there exist two, tl;dr: intervals):
Circle, Ellipse:
degrees: 76.34541
radians: 1.3324789
turns: 0.2120706
Ellipse, Parabola, Hyperbola:
degrees: 126.869896
radians: 2.2142975
turns: 0.3524164
And just for completeness sake, the classic (not-generalizing-to-conic-sections) golden angle:
degrees: 137.50777
radians: 2.3999631
turns: 0.38196602
- improbable22 7y agoI don't know, but you may enjoy this neat paper on such matters: https://arxiv.org/abs/1603.00299 https://arxiv.org/abs/1603.00299
- plus 7y agoI believe the use of the term "magic angle" in this article is at least partially a reference to the technique whose actual technical name is "magic angle spinning" NMR spectroscopy[0]. If course, the angle used in MAS is not related to the angle used in these twisted graphene bilayer structures, but in both cases there appear to be "magical" results that appear only at the specific angle in question. [0] https://en.m.wikipedia.org/wiki/Magic_angle_spinning https://en.m.wikipedia.org/wiki/Magic_angle_spinning