Roll Over Puzzle from Journal Recreation Math 1974 & Martin Gardner Book

AVAILABLE AT http://www.creativecrafthouse.com/ind... Start with an open space in the middle & all cubes showing Butterflies or all showing Trees. Roll the cubes 1 at a time to the open space (using a 1/4 turn of the cube) and reverse the pictures from Butterflies to Trees (or vice-versa) with the open space ending up in the middle again. It's a very challenging puzzle particularly to solve at all and extraordinarily difficult to solve in the minimum number of moves possible (36).

This is a combinatorial puzzle invented by John Harris in the early 1970's with analysis and solution by John from the "Journal of Recreational Mathematics", vol 7, 1974. He determined a solution was possible in 38 moves, however, later computer analysis as documented by Martin Gardner in his book "The Colossal Book of Short Puzzles and Problems", 2006, showed that it is possible in 36 moves.