From reid@math.berkeley.edu  Wed Jan 22 02:29:03 1992
Return-Path: <reid@math.berkeley.edu>
Received: from math.berkeley.edu ([128.32.183.94]) by life.ai.mit.edu (4.1/AI-4.10) id AA24953; Wed, 22 Jan 92 02:29:03 EST
Received: from skippy.berkeley.edu.berkeley.edu by math.berkeley.edu (4.1/1.33(math))
	id AA03361; Tue, 21 Jan 92 23:27:28 PST
Date: Tue, 21 Jan 92 23:27:28 PST
From: reid@math.berkeley.edu (michael reid)
Message-Id: <9201220727.AA03361@math.berkeley.edu>
To: cube-lovers@ai.mit.edu
Subject: Re: Rubik's cube dice tops (Spoiler)
Cc: ronnie@cisco.com

a while ago (last month), Dan (hoey@aic.nrl.navy.mil) writes:

> Last week ronnie@cisco.com (Ronnie Kon) challenged us to find Rubik's
> cube patterns with dice pips for 1, 2, and 3 on the three pairs of
> opposite sides.  He claimed it could be done in fourteen HST, where
> one HST is a turn of a face or center slice by 90 or 180 degrees.  I
> responded that it could be done in thirteen HST.  Here is how.  I will
> use this opportunity to practice the enhanced Varga Rubiksong I
> described (unfortunately with many typos) on 22 Feb 90.

> The (only such) pattern is the composition of Four-Spot and Laughter.
> We have long known the processes

[ description deleted ]

> This uses only 13 HST.  This is also the shortest process I know of in
> the normal metric: 18 QT, which is not so bad for the combination of

here's a shorter way.  in the "flubrd" notation, use:

              D' F^2 R U^2 F^2 B^2 D^2 R^2 L' F^2 U' D^2

which is 11 "HST" (which i call "slice turns").  this is also 12
"face" turns, but 20 quarter turns.  this can also be done in only 14
quarter turns as follows:
                            F^2 U D F B U D F B U D F B'     (*)

note that this can easily be obtained from the well-known manuever for
"laughter":
                              ( F B  C_U )^6                (**)

where  C_  means "turn the whole cube" (as in Bandelow's book).  note
that this manuever reorients the cube.  then manuever (*) is just the
"flubrd" translation of the manuever  M_F (**) M_F'  (without the cube
reorientation), where  M_  means "turn the middle slice," again, as in
Bandelow's book.

here's a question for those out there with 5x5x5 cubes: have you
noticed that the stickers seem to be more happy on the floor than on
the facelets of the cube?  the more i use my cube, the more restless
they seem to become.  does anyone know of a good cure for this?  i'm
thinking of taking them all off, cleaning off the glue (or gum or
whatnot) and gluing them back on, using a stronger glue.  anyone have
any suggestions for what kind of glue?  i'll let you know how my
experiment works.

mike