What field’s literature is this? Figure 6.3 happens to be an especially interesting set of documents to study: This is the entire set of documents on N-rays, a hypothetical and (it was ultimately determined) imaginary phenomenon investigated in the early 1900s. N-rays were a form of radiation first hypothesized to exist in 1904. After an extended period of investigation, the community of physicists investigating the question determined that in fact there were no such things as N-rays! This means the corpus of documents has a convenient, cleanly defined time period. The example also provides insight into the larger scientific process: This is what science looks like when this engine is entirely divorced from any underlying phenomena. In general we can, with Plato, imagine that there is indeed an underlying reality, as well as a social process of science attempting to describe that reality. We can hope that in most cases any particular scientist’s activities, or that of the community in which he participates, is governed by both influences: that of the physical reality and that of the social process.