Nine-Colour Cube Nine-Colour Cube The Nine-Colour Cube ("see below" for other names) is a cubic twisty puzzle. It was invented in 2005 by Milan Vodicka and mass-produced by Meffert's seven years later. Mechanically, the puzzle is identical to the Rubik's Cube; however, unlike the Rubik's Cube, which only has 6 different colours, the Nine-Colour Cube has 9 colours, with the individual pieces having one colour each. The puzzle is known under several different names. Milan Vodicka, the inventor, initially gave it the name "Nine-Colour Scramble Cube", which reflected the key feature and the "de facto" objective of the puzzle. This name was
Prince Rupert's cube the hole through which a cube larger than the original one (up to side length formula_2) may pass. The parts of the unit cube that remain, after emptying this hole, form two triangular prisms and two irregular tetrahedra, connected by thin bridges at the four vertices of the square. Each prism has as its six vertices two adjacent vertices of the cube, and four points along the edges of the cube at distance 1/4 from these cube vertices. Each tetrahedron has as its four vertices one vertex of the cube, two points at distance 3/4 from it on two of