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Date: Thu, 23 Sep 1999 09:28:48 -0700 (PDT)
From: Jaap Scherphuis
Reply-To: jaap@org2.com
Subject: Square 1, Pyramorphix, Cheap Skewballs
To: Cube Lovers
Hi all,
This is my first post to Cube-Lovers, though I have been reading the archives
for a long time now. I'm a 27 year-old mathematician.
Re: Square-1
A few years ago I figured out a solution to the Square-1. It was one of the
hardest puzzles to solve. Though I did theoretically solved it, the solution
was so long and tedious I never actually performed it. In the end I wrote a
program that searched for short sequences that go from cube shape to cube shape
that do not move the corners. In the list it produced were a few useful
sequences moving only a few edges, but all the odd permutations moved a lot of
edges. By combining one of them with some other sequences I finally got my own
parity fixing sequence that is a nice triple edge swap:
Swap FU-BU, LU-RU, FD-BD:
/(3,3)/(1,2)/(2,-4)/(-2,4)/(-1,1)/(3,3)/(0,3)/(3,3)/(0,3)/(6,0)/(6,0)/
The notation is fairly obvious: /=half turn of right hand side, (t,b)=move
top/bottom the given number of twelfths clockwise, negative for anti-clockwise.
I find this much easier to read than any others I've seen, though it is
sometimes easy to forget the leading / if there is one.
Unfortunately I have since lost any other results I got then except for those I
have incorporated into my solution.
The square-1 solving program Matt mentioned can be found in the cube-lovers
archive in the contrib directory.
Re: my webpages
I have recently typed up a lot of my notes and put them on the web in a
text-only preliminary form. Eventually I hope to make them into proper
web-pages with pictures etc.
There are solutions there for:
Alexander's Star, Pocket Cube (2x2x2), Rubik's Cube (3x3x3), Rubik's Revenge
(4x4x4), Profesor's Cube (5x5x5), Dogic, Domino, Impossiball, Megaminx,
Octahedron, Pyraminx, Pyramorphix, Skewb, Brain ball, Rubik's Fifteen, Equator,
It, Ivory Tower (Babylon Tower), Masterball, Orb, Puck, Roundy, Square One,
Topspin, Tower (Whip-It), Rubik's Triamid, Tricky Disky, Rubik's Clock, Lights
Out, Rubik's Magic, Spinout, Crazy Tantrix.
At the moment there is not yet a links page.
You can find it here: http://www.org2.com/jaap/puzzles
I'd appreciate any feedback.
Re: Pyramorphix.
I only have the pocket Pyramorphix, and these are delicate (my first one broke
within 5 minutes). The pieces have small feet which slide through grooves in a
ball. The grooves are formed between 8 triangular pieces which are screwed onto
the ball. By pushing a small screwdriver through at a point where 4 pieces come
together you can unscrew it. It may work best if you bring the 4 flat pieces
together and use the spot between them to unscrew it.
Re: Cheap Skewballs.
This week I bought several cheap puzzleballs at the Oxford Toys'r'Us, all of
the France '98 type. I bought the last two keychain ones (1 uk pound each),
and a couple of normal sized ones (2 uk pounds each). They still have many of
those.
I plan to paint them with diffent designs, e.g.
dodecahedron/icosahedron/octahedron, or rather the spherical projections of
these shapes.
That's all for now.
Bye,
Jaap.
=====
Jaap Scherphuis
Visit the Psion Organiser II CM, XP & LZ Homepage:
URL: http://www.org2.com email: jaap@org2.com