quote: From the general philosophical standpoint, it is of interest to compare the the most complicated machine we can make with the machines we observe in nature, such as the human central nervous system. Warren McCullough of the University of Illinois Medical School has done this in very entertaining terms. He finds that the Eniac computer, containing about 10,000 basic-on-or-off elements, is a million times less complex than the brain, which has 10,000 million neurons. The Eniac, indeed, has about the complexity of the nervous system of the flatworm. It has one advantage : its unit operations are accomplished about a thousand times faster than are the unit operations of the brain. Thus if we made a sort of figure of merit for comparing the competence of man-made and natural machines, taking into account both complexity and speed, we should find the Eniac---for those operations fitted to its very low complexity--only about a thousand times less competent than the human brain.McCullough remarks that if we made a vacuum-tube computer as complex as the brain,it would require a skyscraper to house it, the power of Niagara to operate it and the full flow of water over the falls to keep it cool. This is altogether a criticism of vacuum tubes.If, as seems reasonable to suppose, the use of transistors will permit a further hundred-fold increase in the complexity of our machines, we shall be able to build, in no greater space and with smaller power requirements than are needed now for vacuum-tube computers, a device only 10,000 times less complicated than the brain. Since it will work a thousand times faster, such a transistor device may be, for those jobs to which its low complexity suits it, as much as one-tenth as competent as the human brain. This is an exciting prospect,but it has not yet been achieved.Curiously, its achievement seems to rest on the elimination from electronics of the vacuum tubes which gave electronics birth.