Extending Rubik's Cube notation to 5x5x5
Robert Baker
cobbled together from various sources. :)
To start with, for the benefit of those who may have been living on a
remote island for the last 25 years, I'll recap the standard
(Singmaster) notation:
The front face as a whole, the centre cubie of the front face, or a 90
degree clockwise turn of the front face, are all denoted by the letter
F; it's nearly always obvious from the context which is meant. A 90
degree anticlockwise turn is denoted by F' or F^-1; a 180 degree turn
by F" or F2 or F^2.
Likewise for (B)ack, (L)eft, (R)ight, (U)p and (D)own faces.
The edge pieces are referred to by the names of the faces to which
they belong (e.g. UR); likewise the corners (e.g. UBR). Corners are
usually described clockwise as seen when looking at the corner from
the outside of the cube, but this is not essential.
Additionally, the three inner slices may be if necessary be denoted as
X (the slice parallel to R), Y (the slice parallel to U) and Z (the
slice parallel to F). As turns, X means a clockwise twist as observed
when looking at R; likewise Y and Z.
=============================================
To extend this to the 4x4x4 (Revenge or Master -- I've seen it on sale
under both those names), it is necessary to denote the *six* slices
present, to distinguish between the two edge pieces common to each
pair of faces, and to distinguish between the four centres on each
face. This is done by referring to the slices as f, b, l, r, u and d;
by adding to each edge the slice to which it belongs (e.g. UfR, UbR);
and by adding to each centre the two slices to which it belongs (Ful,
Fur, Fbl, Fbr).
=============================================
All that is now needed is some way of denoting the four entirely new
centres added by the 5x5x5 (Professor); the obvious way is to add the
slice it's on.
=============================================
And there you have it; I believe this notation gives a simple, concise
and systematic way of giving a unique name to every cubie, slice or
turn on every Cube from the Pocket (2x2x2) up to the Professor,
inclusive. I leave you with a view of the Front face of the Professor
Cube, with every cubie labelled with its name (or one of its possible
names) given by this scheme:
UFL | UlF | UF | UrF | FUR
----+-----+----+-----+----
FuL | Ful | Fu | Fur | FuR
----+-----+----+-----+----
FL | Fl | F | Fr | FR
----+-----+----+-----+----
FdL | Fdl | Fd | Fdr | FdR
----+-----+----+-----+----
FDL | FlD | FD | FrD | FRD
Robert Baker
(Don't know what a Pyraminx Crystal is? You can see one here:
<http://www.mefferts.com/products/index.php?category_new=13>)
--
Zork: one nation, underground, invisible, with loot and adventure for all
Ed Murphy
> Challenge to readers: Devise a notation for the Pyraminx Crystal! :-)
>
> (Don't know what a Pyraminx Crystal is? You can see one here:
> <http://www.mefferts.com/products/index.php?category_new=13>)
Label the faces T, TF, TFL, TFR, TPL, TPR,
B, BP, BPL, BPR, BFL, BFR
(Top Bottom Front Posterior Left Right)
T indicates one clockwise rotation
T2 indicates two CW rotations
T' indicates one CCW rotation
T2' indicates two CCW rotations