Message #664

From: Roice Nelson <roice3@gmail.com>
Subject: Void Cube analogues
Date: Thu, 07 May 2009 22:44:18 -0500

I saw this at www.mathpuzzle.com:

*Void Cube and other Variants* The 2007 winner of the Nob Yoshigahara
Puzzle Design Competition was the Void
Cube<http://www.youtube.com/watch?v=pDvcmiuxsNU>(youtube), by
Katsuhiko Okamoto. These are now available at
gentosha-edu.co.jp <http://www.gentosha-edu.co.jp/products/div-cl.html>.
Easier to order are some of the exotics now available at mefferts.com.
The mirror
block <http://www.yousaytoo.com/funforever/mirror-block-rubik-s-cube/11386>(yousaytoo)
is another variant.

These are pretty neat looking, and it would be relatively easy to make code
changes for analogues… simply don’t draw 1C pieces, and alter the function
which checks for a solved puzzle accordingly. Anyone want to comment on how
this affects the difficulty or number of reachable positions?

One random thing I could quickly observe is that number of checkerboard
patterns on MC4D is extended for the void cube. As a specific
example, an 8-cycle
version of the checkerboard<http://groups.yahoo.com/group/4D_Cubing/photos/album/872915976/pic/1983894585/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc>is
now possible (in that picture, one of course needs to ignore the 1C
pieces).

Some more questions I’d be interested to hear thoughts on: Could you have a
physically stable 4D void cube version with no 1C pieces and no 2C pieces?
I think the answer might be yes. And if so, do stable n-dimensional void
cubes only need two piece types in general?

Take Care,
Roice