- Understanding Noise in Twentieth-Century Physics and Engineering
Noise is a common experience in the contemporary world. Din from trafﬁc, construction sites, factories, and neighbors bother urban residents. Radio listeners, television watchers, and mobile phone users have to endure statics and fading from time to time. Music lovers have debated whether jazz, atonal composition, rock and roll, rap, and abstract expressionism are art or nuisance. Scientists try to retrieve genuine signals from ﬂuctuating data. Engineers design devices, software, or systems to ﬁlter out disturbance to the normal functioning of technology. Mathematicians and physicists examine randomness. Traders and economists attempt to predict markets’ future trends beneath highly irregular commodity prices. Decision makers cope with all kinds of uncertainty. No matter whether we understand the term as annoying sound or random ﬂuctuations, we simply cannot live a life without encountering noise.
Despite its ubiquity in modern times, noise has rarely been a focus of historical studies of recent science and technology. There may be an obvious reason for this lack of attention: noise largely reveals what science and technology are not, instead of what they are. Noise is an environmental plight of industrialization, an obstacle to the advancement of scientiﬁc knowledge, a subversive force to technology, a barrier to prediction, estimation, and control, and a symptom of disorder. As a result, noise often exposes the limitations of science and technology. While such limitations have played an important part in the development of science or technology, they are generally conceived as a background to this development, and thus scarcely become the subject of close investigations.
A number of recent historiographical turns, however, have begun to change this situation. Inspired by the cultural histories of senses that ﬂourished [End Page 1] in the past few decades, historians and sociologists of technology have developed the area of sound studies. Scholars working in sound studies have examined closely various issues related to the generation, interpretation, and control of acoustic noise, ranging from the noise abatement movements and the treatment of noise as a diagnostic tool for mechanical problems to the use of mechanical noise in music composition and the measurement of hearing loss due to noisy ambience.1 Moreover, historians and philosophers of science have paid increasing attention to random ﬂuctuations. They have either looked into the studies of noise (in the abstract, mathematical sense), such as Brownian motion and electronic noise, in several branches of physics investigated scientists’ statistical criteria for judging an experimental claim from noisy data, or explored the roles of such stochastic noise in self-organization or biological evolution.2 Finally, owing to the ongoing interest in the history of information science and technology, how engineers and scientists dealt with noise in communication, control, and computing systems has been a notable research question.3
Built upon the aforementioned literature, this special issue of Perspectives on Science presents six case studies of noise. The disciplines under consideration include acoustics, statistical mechanics, applied mathematics, quantum electronics, electronic and telecommunication engineering, and computer science. The time spans the two World Wars and the Cold War, while the geographical regions encompass North America and Europe. Roland Wittje takes up a subject that has been studied by historians: acoustical noise. He points out the importance of understanding the term’s various meanings in relation to the applications within which these meanings were deployed. Nineteenth-century scientists dealt with noise within the framework of musicology. But the First Great War demanded that they reframe it in terms of the sounds of the battleﬁeld. Scientists worked to develop sound-ranging systems that could, for example, pick up the signal from a particular artillery piece while ﬁltering out the din of other ﬁghting. In other situations, noise itself became the signal as acousticians experimented with receivers that could register the sounds of the pumps, propellers, and engines of enemy submarines. Meanwhile, in the war and postwar years, research into acoustical noise began to merge with electrical engineering in the context of electro-acoustic technologies like telephony and radio.
Niss’s, Yeang’s, and Bromberg’s articles are concerned with physicists’ research on random ﬂuctuations due to molecular thermal agitation, the...