Before electronic computers were generally available, when scientists wanted the results of some calculations, they sometimes hired “computers” [b114], which were people trained to perform the calculations.
This concept reminds me of an interesting plot in《Three Body Problem》, where, in the three-body-problem visual game, a simplified "human computer" is described: assuming there are three people facing to each other, holding either red or white light, if a person see both the others hold white light, he would hold the white light as well; otherwise he would hold the red light. This game happens to represent the binary system in computer.