God’s number
n.— «But perhaps the most difficult challenge in cubing, and the one that has attracted the interest of Northeastern University researchers, is the attempt to determine the minimum number of moves it would take to solve the cube from even the most difficult of its more than 43 quintillion possible arrangements—that’s 43 followed by 18 zeros. In cubing, this is known as the pursuit of “God’s number” (because God would always use the fewest moves possible to solve the puzzle). Next month, at a symposium in Canada, Dan Kunkle, a doctorate student in computer science, and Gene Cooperman, a professor of computer science, will announce the lowest proven “God’s number” to date: 26.» —“The search for ‘God’s Number’ in a Rubik’s Cube” by Billy Baker Boston Globe June 25, 2007. (source: Double-Tongued Dictionary)