The Computer

The computer is basically a device for ingesting, judging, and otherwise processing or usefully modifying knowledge. Thus it enlarges brainpower in the same way that other man-made machines enlarge muscle power. Like man, the computer expresses knowledge in terms of symbols; man’s symbols are letters and numbers, and the machine’s symbols are electromagnetic impulses that represent letters and numbers. Although man must usually instruct or program the machine minutely, its chief present advantage is that it can manipulate symbols a million times faster than a man with pencil and paper, and can make calculations in a few minutes that might take man alone a century. An expert has remarked that the difference between doing a calculation by hand and by computer is the difference between having one dollar and having a million. Sometimes the difference is infinite; only a computer can calculate swiftly enough to analyze the data from a satellite, or to enable man to control the flight of a missile.