In science if you know what you are doing you should not be doing it.
In engineering if you do not know what you are doing you should not be doing it.
Of course, you seldom, if ever, see either pure state."
(In The Art of Doing Science and Engineering: Learning to Learn (1975, 2005), 5.)
Image: Color of each pixel is Hamming distance between the binary representations of its x and y coordinates, modulo 16, in the 16-color system.