The whistleblowing bankers who were sent to jail
bbc.co.uk10 pointsby bainsfather2 comments
- that if you repeat any sequence of moves enough times, you will always return to your starting position - with hindsight this now seems obvious, which I guess means that I've internalised some new knowledge.
- that there are 'macros' - sequences of moves that shift just a few 'cubies' and leave the rest of the cube unchanged (I vaguely knew this already).
- that there is a logical way to make such macros using 'almost commuting' pairs of sequences.
- why I could never find a macro that swapped the positions of only 2 cubies (because such a move would be an odd permutation of the cubies, whereas moving a side (the basic move you can make with a cube) is an even permutation).
- how to physically disassemble a cube, so that I could recover the solved cube - very useful when I was getting started with finding macros.
I found these courses allowed me to do calculations (e.g. contour integrals, conformal transformations) that were useful but always felt like black magic. I don't have an intuitive feel for the subject. I am wondering if this book will help me with that?