I found a few old Excel-sheets with calculations, when I was cleaning up files on my computer today. Have done a lot of fun stuff on Excel in the past. I found a sheet where I calculated the correct SO3-element on a threedimensinal transformation. Don't remember why I did that at the time, but I have been fascinated by doing correct - photographical 3D imaging, starting from scratch, whithout any help from a CAD-program.
Another one of those sheets where calculations of cubic equations, using one of the most beautiful substitutions I have ever discovered: the Vieta substitution. It is a pease of art.
Didn't find any of my fractal-calculations, but that might been a while since I played with those. My favorite, the Newton-fractal of the equation x^3-1=0, using different coulors for the different solutions is also one of my historical achievements.
One fun thing I found was also an equation for a Klein-bottle. I had a suggestion of how to construct it, but it took some serious calculations on Excelsheets, before I was convinced that my formulae was correct.
So where did all this interest start? I am not sure, but there was quite a few question marks left, once I had left my engineering studies. One was to understand the relation - the homomorphism between SO3 and SU2. Actually, when I remembered the presentation at some obscure course in quantum physics, I remembered it the wrong way. It is nor SO3 that is homomorph to SU2, even though the matrix is smaller (9 compared with 8), it is the other way around. It is not that difficult to realise why. S03 may be seen as a 3-dimensional ball, with radius of pi (half-a-turn). At the edge it is connected (topologically) whith the opposite side. SU2 on the other hand is the three-dimensional surface of a 4-dimensional ball, which is two balls (a positive and a negative 3-dimensional ball connected at their 2-dimensional shell.
SO3 is for those who are not familiar with terminology, the orthonormal matrix, with determinant of 1. SU2 is the komplex 2-dimensional matrix with the determinant of 1. When I investigated them, I even determined specific homomorpisms, how they could be translated into one-another. The subject still fascinates me. I have not yet been able to determine relations between higher orders of SO and SU, where the numbers of unknown are equal.
SO2 and SU1 are isomorphic, but what about SU4 and S06, or SU11 and SO16? I am convinced that at least someone have investigated for real... but maybe it is not that is too much technique and too little theory. SU23 and SO33 *s*