Minus Cube

From Wikipedia, the free encyclopedia

The Minus Cube puzzle

A small cube of the Minus Cube in the disassembled state

The Minus Cube (Russian: «Минус-кубик») is a 3D mechanical variant of the n-puzzle which was manufactured in the Soviet Union. It consists of a bonded transparent plastic box containing seven small cubes, each glued together from two U-shape parts: one white and one coloured. The linear size of the interior of the box is twice the size of a small cube. The small cubes are moveable inside the box and the goal of the puzzle is to place the cubes in such a way that on each side of the box, all of the faces of the small cubes are one color.

There were two types of Minus Cubes manufactured: the so called "Moscow Minus Cube" (red-white) and "Sverdlovsk Minus Cube" (blue-white), each named after the cities in which they were produced. They differed only in the orientation of one of the small cubes. Because of this difference there are 12 times as many "solved" arrangements for the Moscow Minus Cube, and the Sverdlovsk Minus Cube is 12 times more difficult to solve. However, if one does not confine oneself to these two types of the Minus Cube, there are 48 Minus Cube variants which can be solved.