Speaking about symmetry, look out our window, and you may see a cardinal attacking its reflection in the window. The cardinal is the only bird we have who often does this. If it has a nest nearby, the cardinal thinks there is another cardinal trying to invade its territory. It never realizes it is attacking its own reflection. Cardinals don't know much about mirror symmetry!
Martin GardnerAs Bertrand Russell once wrote, two plus two is four even in the interior of the sun.
Martin GardnerOne day, when I was doing well in class and had finished my lessons, I was sitting there trying to analyze the game of tic-tac-toe... The teacher came along and snatched my papers on which I had been doodling... She did not realize that analyzing tic-tac-toe can lead into dozens of non-trivial mathematical questions.
Martin GardnerModern science should indeed arouse in all of us a humility before the immensity of the unexplored and a tolerance for crazy hypotheses.
Martin Gardner