About an unintuitive concept that explains unsolvable Puzzles

Video Description

What is the reason that certain seemingly simple problems, like some special Rubic's Cubes, can't be solved? We have to investigate the property known as Parity... Try the 15 Puzzle online: https://lorecioni.github.io/fifteen-puzzle-game/ Our parity proof: "The Sign of a Permutation", Keith Conrad, https://kconrad.math.uconn.edu/blurbs/grouptheory/sign.pdf Theorem 2.1. Article about the 15 Puzzle: https://daily.jstor.org/square-space-fifteen-puzzle/ More on parity: https://en.wikipedia.org/wiki/Parity_of_a_permutation Chess Tactic Solution: Ke2(!) https://en.chessbase.com/post/chessbase-puzzles-loyd-s-steinitz-gambit (bottom of the page)