This paper aims to cast light on the reasons that explain the shift of opinion—from scepticism to realism—concerning the reality of atoms and molecules in the beginning of the twentieth century, in light of Jean Perrin’s theoretical and experimental work on the Brownian movement. The story told has some rather interesting repercussions for the rationality of accepting the reality of explanatory posits. Section 2 presents the key philosophical debate concerning the role and status of explanatory hypotheses c. 1900, focusing on (...) the work of Duhem, Stallo, Ostwald, Poincaré and Boltzmann. Section 3 examines in detail Perrin’s theoretical account of the molecular origins of Brownian motion, reconstructs the structure and explains the strength of Perrin’s argument for the reality of molecules. Section 4 draws three important lessons for the current debate over scientific realism. (shrink)

Despite much excellent work over the years, the vast history of scientific filmmaking is still largely unknown. Historians of science have long been concerned with visual culture, communication and the public sphere on the one hand, and with expertise, knowledge production and experimental practice on the other. Scientists, we know, drew pictures, took photographs and made three-dimensional models. Rather like models, films could not be printed in journals until the digital era, and this limited their usefulness as evidence. But that (...) did not stop researchers from making movies for projection at conferences as well as in lecture halls, museums and other public venues, not to mention for breaking down into individual frames for analysis. Historians of science are more likely to be found in the library, archive or museum than the darkened screening room, and much work is still needed to demonstrate the major effects of cinema on scientific knowledge. Film may have taken as long to change science as other areas of social life, but one can begin to glimpse important ways in which ‘image machines’ were beginning to mediate between backstage experimental work and more public demonstration even around 1900. (shrink)

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.. (shrink)

Randomness, uncertainty, and lack of regularity had concerned savants for a long time. As early as the seventeenth century, Blaise Pascal conceived the arithmetic of chance for gambling. At the height of positional astronomy, mathematicians developed a theory of errors to cope with random deviations in astronomical observations. In the nineteenth century, pioneers of statistics employed probabilistic calculus to define “normal” and “pathological” in the distribution of social characters, while physicists devised the statistical-mechanical interpretation of thermodynamic effects. By the end (...) of the century, a probabilistic worldview—as historians Lorrain Daston, Theodore Porter, and Stephen Stigler. (shrink)

In this paper, we examine the pioneering research on electronic noise—the current fluctuations in electronic circuit devices due to their intrinsic physical characteristics rather than their defects—in Germany and the U.S. during the 1910s–1920s. Such research was not just another demonstration of the general randomness of the physical world Einstein’s work on Brownian motion had revealed. In contrast, we stress the importance of a particular engineering context to electronic noise studies: the motivation to design and improve high-gain thermionic-tube amplifiers for (...) radio and wired communications. Engineering scientists’ endeavors to understand electronic noise started in 1918, when Walter Schottky at Siemens formulated a theory of “shot noise,” current fluctuations owing to the random emissions of discrete electrons in a tube. Schottky’s theory was revised and experimentally tested at Siemens, General Electric, and AT&T during the 1920s, leading to the discoveries of several other types of noise and an increasing interest in the thermal fluctuations in electronic circuits. In 1925–1928, J.B. Johnson and Harry Nyquist at Bell Labs developed a theory of thermal noise for any electrical resistor at a non-zero temperature. Although these studies were initiated to chart the fundamental performance limit of electronic technology, they ended up assisting the empirical determination of individual electronic components’ characteristics. (shrink)

The use of motion pictures for research has a long history, of course, but beyond documenting a phenomenon and then projecting it for demonstration, scientists using this technology spent much energy figuring out how to extract information from a strip of film. Understanding film (or audiovisual) analysis is therefore necessary to grasping the relationship between an object of study, moving-image technology, and scientific evidence. This article explores one common technique within that history of film analysis: projecting a frame of the (...) motion picture and then tracing the object of study onto paper, which was especially important for behavioral sciences such as developmental psychology or ethology. Behavior became tangible through a variety of means, but for those who relied on film for their observations, such as developmental psychologist Arnold Gesell, behavior took form at least partly through the process of tracing. Gesell's use of this technique reveals the broader functions of tracing as well as the patterns that emerge from its interplay with other inscriptions in the creation of evidence. How does behavior take form? The practice of tracing provides one answer to this larger question. (shrink)

This paper examines how the production, content and reception of the film Antony van Leeuwenhoek (1924) influenced the historical framing of science. The film features microcinematography by the pioneering Dutch filmmaker Jan Cornelis Mol (1891–1954), and was part of a dynamic process of commemorating seventeenth-century microscopy and bacteriology through an early instance of visual re-creation – a new way of using scientific material heritage, and of enabling audiences to supposedly observe the world of microscopic organisms in just the same way (...) as the Dutch scientist Antoni van Leeuwenhoek (1632–1723) had observed them for himself. Knowledge transfer concerning material culture, around both historical and contemporary instruments, was the determining factor in the microcinematography practices applied in this film. The production and experience of the film also mirrored the seventeenth-century process of experimentation, playing with optics, and visualizing an entirely new and unknown world. Unlike other biographical science films of the 1920s, Antony van Leeuwenhoek featured abstract depictions of time and movement that allowed the audience to connect the history of science with microcinematography, contributing to the memory of Van Leeuwenhoek's work as the origins of bacteriology in the process. (shrink)