Salting Quotes (1 quote)
Curves that have no tangents are the rule. Those who hear of curves without tangents, or of functions without derivatives, often think at first that Nature presents no such complications. The contrary however is true. Consider, for instance, one of the white flakes that are obtained by salting a solution of soap. At a distance its contour may appear sharply defined, but as we draw nearer its sharpness disappears. The eye can no longer draw a tangent at any point. The use of a magnifying glass or microscope leaves us just as uncertain, for fresh irregularities appear every time we increase the magnification. An essential characteristic of our flake is that we suspect that any scale involves details that absolutely prohibit the fixing of a tangent.