[next] [prev] [up] Date: Sat, 04 Dec 93 09:15:56 -0500 (EST)
[next] ~~~ [up] From: Jerry Bryan <BRYAN%WVNVM.BITNET@mitvma.mit.edu >
~~~ ~~~ [up] Subject: First Post

This is my first post to Cube-Lovers, so I will introduce myself
briefly. I have been cubing since about 1979 or 1980 or so when
the cubes first appeared on the market. I have been cubing with
a computer since about 1985, and have been active on the Internet
since about 1985 (purely a coincidence of dates). I have looked
for years for a cubing list, and never found one until now.
I always looked for "Rubik" (or sometimes "Rubic"). For some silly
reason, it never occurred to me to look for "cube".

I have long since read Hofstadter's two Scientific American articles,
as well as the reprints in METAMAGICAL THEMAS. The reprints, by
the way, are excellent because of the additional information in the
appendices. I also have a copy of Singmaster and Frey's
HANDBOOK OF CUBIC MATH. I have tried unsuccessfully for years to
get copies of Singmaster's earlier work -- the circulars, for
example. However, I suspect that the HANDBOOK includes most if not
all of the earlier material. Also, (and you won't believe this) I have
just read all thirteen years of the archives of Cube-Lovers.

My primary interest has been in calculating God's Algorithm. I am
interested in brute force breadth first tree searches. In other
words, my work is akin to the solutions of the 2x2x2 and the corners
of the 3x3x3 posted by Dan Hoey and others. It is not akin to
Thistlethwaite's methods. I am interested to see, however, that
major recent progress appears to have been made on Thistlewaite's
method.

I have calculated God's Algorithm for the 2x2x2 cube and the corners
of the 3x3x3. My results agree with those that have been posted here,
with the exception that my search is 48 times smaller (24*2), due
to the exploitation of a rotation and reflection group of the cube.
I have also calculated God's Algorithm for the edges of the 3x3x3.
This is a much larger problem, and took about a year running
continuously on two machines. The resulting output file is about
4.2 gigabytes of data, and is stored on 31 reels of magnetic tape.
This result includes the "48 times smaller" factor, else it would
have been 204 gigabytes of data stored on 1464 reels of magnetic
tape.

I understand that this list has been very quiet of late. But
assuming some modicum of interest, I will post more details
of my results in subsequent messages.

 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Robert G. Bryan (Jerry Bryan)              (304) 293-5192
Associate Director, WVNET                  (304) 293-5540 fax
837 Chestnut Ridge Road                     BRYAN@WVNVM
Morgantown, WV 26505                        BRYAN@WVNVM.WVNET.EDU

If you don't have time to do it right today, what makes you think you are
going to have time to do it over again tomorrow?


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