Dr. Wilder claims to be the first person to recognize that the 'center of disturbance', center of a ridge pattern, is always where a volar pad exists. Wilder is also noted for the idea that ridges are ridge units fused together, a hypothesis which still remains unproven.
Tic-tac-toe is a game that is traditionally played by being drawn on paper, and it can be played on a computer or on a variety of media. History of Tic Tac Toe An early variation of the game was played in the Roman Empire, around the 1st century B.C.
How many games of Tic-Tac-Toe are there? This is another question which was prompted by a comment in a Mathematical Recreations article in Scientific American. As I recall, the author made an offhand remark about 9! (that is, 362,880) being the number of possible tic-tac-toe games.