M101: The Pinwheel Galaxy - reminiscent of Fibonacci's sequence, the Golden Ratio. Image here: http://moonrocksastro.com/wp-content/uploads/2017/05/M101-The-Pinwheel-Galaxy-25.jpg Copyright: Paul C. Swift https://c1.staticflickr.com/5/4189/33793989444_dfc1544208.jpg M101: The Pinwheel Galaxy by Paul...