The 120 Polyhedron
The (x, y, z) coordinates for all of the vertices
can be put into the form
n φm
where n = -2, -1, 0, 1, 2 and m = -1, 0, 1 and φ is the Golden ratio.
Vertex |
Type |
X |
Y |
Z |
1 |
A |
0 |
0 |
2 |
2 |
B |
1 |
0 |
φ |
3 |
A |
φ-1 |
1 |
φ |
4 |
C |
0 |
φ-1 |
φ |
5 |
A |
-φ-1 |
1 |
φ |
6 |
B |
-1 |
0 |
φ |
7 |
A |
-φ-1 |
-1 |
φ |
8 |
C |
0 |
-φ-1 |
φ |
9 |
A |
φ-1 |
-1 |
φ |
10 |
A |
φ |
φ-1 |
1 |
11 |
C |
1 |
1 |
1 |
12 |
B |
0 |
φ |
1 |
13 |
C |
-1 |
1 |
1 |
14 |
A |
-φ |
φ-1 |
1 |
15 |
A |
-φ |
-φ-1 |
1 |
16 |
C |
-1 |
-1 |
1 |
17 |
B |
0 |
-φ |
1 |
18 |
C |
1 |
-1 |
1 |
19 |
A |
φ |
-φ-1 |
1 |
20 |
C |
φ |
0 |
φ-1 |
21 |
A |
1 |
φ |
φ-1 |
22 |
A |
-1 |
φ |
φ-1 |
23 |
C |
-φ |
0 |
φ-1 |
24 |
A |
-1 |
-φ |
φ-1 |
25 |
A |
1 |
-φ |
φ-1 |
|
Vertex |
Type |
X |
Y |
Z |
26 |
A |
2 |
0 |
0 |
27 |
B |
φ |
1 |
0 |
28 |
C |
φ-1 |
φ |
0 |
29 |
A |
0 |
2 |
0 |
30 |
C |
-φ-1 |
φ |
0 |
31 |
B |
-φ |
1 |
0 |
32 |
A |
-2 |
0 |
0 |
33 |
B |
-φ |
-1 |
0 |
34 |
C |
-φ-1 |
-φ |
0 |
35 |
A |
0 |
-2 |
0 |
36 |
C |
φ-1 |
-φ |
0 |
37 |
B |
φ |
-1 |
0 |
|
Vertex |
Type |
X |
Y |
Z |
38 |
C |
φ |
0 |
-φ-1 |
39 |
A |
1 |
φ |
-φ-1 |
40 |
A |
-1 |
φ |
-φ-1 |
41 |
C |
-φ |
0 |
-φ-1 |
42 |
A |
-1 |
-φ |
-φ-1 |
43 |
A |
1 |
-φ |
-φ-1 |
44 |
A |
φ |
φ-1 |
-1 |
45 |
C |
1 |
1 |
-1 |
46 |
B |
0 |
φ |
-1 |
47 |
C |
-1 |
1 |
-1 |
48 |
A |
-φ |
φ-1 |
-1 |
49 |
A |
-φ |
-φ-1 |
-1 |
50 |
C |
-1 |
-1 |
-1 |
51 |
B |
0 |
-φ |
-1 |
52 |
C |
1 |
-1 |
-1 |
53 |
A |
φ |
-φ-1 |
-1 |
54 |
B |
1 |
0 |
-φ |
55 |
A |
φ-1 |
1 |
-φ |
56 |
C |
0 |
φ-1 |
-φ |
57 |
A |
-φ-1 |
1 |
-φ |
58 |
B |
-1 |
0 |
-φ |
59 |
A |
-φ-1 |
-1 |
-φ |
60 |
C |
0 |
-φ-1 |
-φ |
61 |
A |
φ-1 |
-1 |
-φ |
62 |
A |
0 |
0 |
-2 |
|
φ = (1 + √5) / 2 = 1.618033989...
φ-1 = φ - 1 = 0.618033989...
Type "A" =
|
Octahedron vertex
|
Type "B" =
|
Icosahedron vertex
|
Type "C" =
|
Tetrahedron, Cube, Dodecahedron vertex
|
Note the z-components are 2, φ, 1, φ-1, 0,
-φ-1, -1, -φ, -2.
This defines 9 layers or planes (in this orientation of the 120 Polyhedron).
The Cube's 4 vertex-to-opposite-vertex axes were used
for the Cube and Octahedron's rotations.
What are the rotation angles?
|α| + |β| = 120°
For an arbitrary (x, y, z) coordinate, if rotated by these angles
what is the resulting coordinate (x', y', z')?
Copyright September, 2007 by Robert W. Gray