Puzzles
He walked a mile south, a mile east, a mile north, and was back where he started
An explorer walks one mile due south, turns and walks one mile due east, turns again and walks one mile due north — and finds himself exactly back at his starting point. He sees a bear. What color is the bear?
Reveal the answer
White: he started at the North Pole, where walking any direction is 'south.' Martin Gardner popularized the riddle in Scientific American in February 1957 — and later noted the North Pole isn't the only answer. Start near the South Pole at just the right distance, and walking south, one mile east around the pole, then north also brings you home, for infinitely many other starting points.
— Martin Gardner, Mathematical Games column — Scientific American, February 1957