[next] [prev] [up] Date: Mon, 22 Jun 92 09:19:00 -0500 (CDT)
~~~ ~~~ [up] From: PAul STevens - MACC - 2-9618 <STEVENS@macc.wisc.edu >
[next] [prev] [up] Subject: Re: reminiscences

reid@math.berkeley.edu writes:

well, i've droned on long enough. anyone else got any interesting stories?

I think my solution may be considered cheating; but I was pretty proud of
it. I had almost decided to give up on the thing. But I had just
designed and built an 8080 'computer'. It had 2k bytes of 2102's and
had to be programmed with binary switches and whenever the program
clobbered itself the entire program had to be re-entered in binary.

So I wrote a program to look for combinations of moves that left most
of the cube alone and only moved a few cubelets. I studied the best of
these at great length and managed to combine some into 'better' moves,
eventually finding some that moved only three or so cubelets. These
were then combined into a solution. A rather god-awful solution I
think. But my fingers learned the moves and I have never abandoned them
for fear of becoming totally confused. The same ugly solution has been
passed on for at least one generation and perhaps will persist for
hundreds of years.

I still don't know what a group or commutator or ... is except what I
have deduced from reading mail from this group. I get the front face
corners exactly right, the back corners in the proper position, and then
the back corners rotated properly.

Finally the edges go where they belong one at a time, first on the
front and back and finally the four on the sides/top/bottom.

I have noticed a lack of discussion of cubes that have pictures on
them such that the entire cube can be right except that a single
center can be upside-down. I have also painted a 4x4x4 so that the
center 4 squares on each face have to be in the proper position. Every
time I solve this cube I have to rediscover how it is done. My fingers
refuse to learn it for me.

Behind the back? You gotta be kidding!


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