Timeline of United States inventions (1890–1945) installing driven conveyor belts that could produce a Model T in ninety-three minutes. 1901 Safety razor (disposable) A safety razor protects the skin from all but the edge of the blade while shaving skin. King Camp Gillette, a traveling hardware salesman of Fond du Lac, Wisconsin invented the double-edged, disposable safety razor attached to a re-usable razor handle. Beforehand, dull razors were taken to barbers for sharpening. With Gillette's double-edged and disposable blades, a uniform shave on a man's face could be achieved with a fresh blade and disposed after it was used. Gillette applied for a patent in 1901.
Occam's razor reject the simple hypotheses. Recent advances employ information theory, a close cousin of likelihood, which uses Occam's razor in the same way. Francis Crick has commented on potential limitations of Occam's razor in biology. He advances the argument that because biological systems are the products of (an ongoing) natural selection, the mechanisms are not necessarily optimal in an obvious sense. He cautions: "While Ockham's razor is a useful tool in the physical sciences, it can be a very dangerous implement in biology. It is thus very rash to use simplicity and elegance as a guide in biological research." In biogeography,