Plenty of room at the top
2015
Feynman, from nanotechnology to the Challenger disaster In 1959 the physicist Richard P. Feynman gave a talk to the American Physical Society with the title ‘Plenty of Room at the Bottom’ where he addressed the possibilities of miniaturisation, or, as he said, ‘manipulating and controlling things on a small scale’. He argued that the technological possibilities are almost unlimited, and he carried out some staggering thought experiments. He started by asking the question: ‘Why cannot we write the entire 24 volumes of Encyclopaedia Britannica on the head of a pin?’ (He was referring to the 1947 edition.) He demonstrated that we in principle can, and gave the following justification. The diameter of a head of a pin is 1/16 of an inch (approximately 1.5 mm). If the diameter is magnified by a factor of 25,000, the area of the pinhead will be approximately the same size as all the pages of Encyclopaedia Britannica. The challenge then is to reverse the process, to diminish the printed pages of Encyclopaedia Britannica by a factor of 25,000. And it can in principle be done. If we take the smallest printed dot that can be seen by the human eye, a dot with a diameter of 0.2 mm, and diminish it by a factor of 25,000, the dot will cover an area of approximately 1,000 atoms. Therefore, he included plenty in the heading of his talk: there is not only space, but plenty of space at the bottom. Feynman also pointed out that this would not be an encoded version of the Encyclopaedia, but a (graphical) copy, containing the exact layout, and all the pictures.