Four Marble Puzzle: another of my favorite physics brain teasers- move all four marbles to their corner locations simultaneously. Each slot slopes down towards the center such that the marbles tend to stay at the center- so, how would one get them to roll outward at the same time? The solution to this puzzle (like others featured here) relies on some fun basic physics principles. Beautiful and well-made puzzle from Creative Crafthouse. Solution: centripetal acceleration and rotational kinetic energy will raise the potential energy of all marbles simultaneously. Watch full video : https://www.youtube.com/watch?v=WD6sEFH1AHU