Midwest Junto for the History of Science Fifty-Sixth Annual Meeting April 5-7, 2013, University of Notre Dame

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1 Midwest Junto for the History of Science Fifty-Sixth Annual Meeting April 5-7, 2013, University of Notre Dame Of thinkers and tinkers Science meets technology at the invention of the triode Eliseo Fernández Linda Hall Library Marie Boas Hall. Recollections of a History of Science Guinea Pig Isis 90: S68-S83, 1999: Stephenson, always interested in intellectual history, turned seriously to the history of medieval technology, writing an excellent little article, "In Praise of Medieval Tinkers. Regrettably Sarton, to whom he naturally sent an offprint, replied brusquely, indeed rudely, that he was interested in medieval thinkers, not tinkers, a revealing comment. George Sarton Marie Boas Hall was awarded the Sarton medal in

2 Disparagement of Technological Work That comment is indeed revealing, not just of Sarton s ideological stance on the prevalent disparagement of technological work. This attitude has ancient roots and has deeply influenced Western thought, especially in the changing philosophical assessments of the relations of theory and praxis. Reversal of Attitude Technoscience: term promoted by Bruno Latour. Paul Forman s, The primacy of science in modernity, of technology in postmodernity and of ideology in the history of technology (2007). Scientific and technological research and innovation are so intertwined, conceptually, economically and politically, that their natures and their interplay are hard to discern. 2

3 Scientific versus Technological Research To some extent it is possible to distinguish their common characteristics and their contrasting differences (as to goals, cognitive styles, methods, etc.), when they are properly grasped as the outcomes of historically conditioned human endeavors Here we will investigate the practice of tinkering as a peculiar cognitive instrument in the generation of technological novelty The Triode Valve or Electronic Tube We will use the invention of the triode thermionic valve, a crucial innovation of the early twentieth century, for a discussion of the complex interrelations of theory and praxis and the role of tinkering in the generation of technological novelty. The multiple functions of the triode valve (switch, rectifier, amplifier, detector, modulator) were initially applied to wireless radio in broadcasting and reception. This was the initial step in a broadening cascade of innovations: television, digital computers and many other contrivances of the ever-expanding web of artifacts that shape our daily existence. In succeeding decades the triode was superseded almost everywhere by its solid-state successor, the transistor or crystal triode: 3

4 The Edison Effect 1880 Experimenting to improve his incandescent lamps, Edison introduced electrodes into the evacuated bulbs. During one of his tests he measured an electric current passing from the hot filament to the electrode connected to the positive terminal of a battery. No current was registered when the electrode was connected to a negative voltage with respect to the filament. He did not understand the physics behind this. Fleming and the Diode John Ambrose Fleming

5 De Forest and the Audion 1906 Two Facts in the Invention of the Triode First: De Forest had no idea of how the Audion worked in terms of physical theory, neither before nor after arriving at its creation. Second: he reached his invention by a process of protracted, painstaking tinkering upon various different realizations of Fleming s diode. 5

6 Problems of Telegraphic and Telephonic Transmission ATTENUATION: At this time (1906) the expanding enterprises of line and wireless telegraphy were both confronted with a difficult problem: the rapid attenuation of the signals at increasing distances, combined with higher levels of noise (statics). Practical telephony was only possible by line transmission. SOUND TRANSMISSION: Wireless telegraphy had become a successful venture, but telegraphy is a digital process. Switching the current on and off produced signals as sequences of dots and dashes separated by silences. Wireless telephony requires processing of analogue information encoded in the changing oscillations of the human voice. No practical process was available to do this. Four Inventions Needed With hindsight we see that four important inventions were needed to conquer attenuation in line telegraphy and make possible long-distance wireless transmission of acoustic signals (radio): an amplifier for boosting the energy of the signals; a modulator to incorporate the weak analogue signal from a microphone, a low (audio) frequency alternating current within a powerful high frequency wave that would travel long distances with low attenuation; a detector (demodulator) at the receiving end, to extract the original oscillation pattern from the modulated high frequency wave; and a transmission oscillator (i.e., a high frequency electromagnetic wave generator) to provide a stable high energy wave to be modulated by the audio signals. 6

7 Four Inventions Within a Single Artifact It was immediately realized that by feeding appropriate signals to its grid, the triode will work as an amplifier, detector and modulator. Once the physics behind the triode was understood it was seen that these three functions essentially result from one single physical process. Edwin Armstrong The fourth invention, the electronic oscillator, had to wait another six years for its experimental realization through the work of Edwin Armstrong in Dawn of the Electronics Era Before this invention, high frequency continuous wave generation was very expensive and required gigantic alternators or costly arc generators. All this was changed by the Audion. By the early 1920 s, the era of commercial radio had dawned and the more reliable and cheaper triodes were driving both the expanding broadcasting radio stations and the proliferating domestic receivers. Schematic of an early Audion radio receiver 7

8 Thinking About Tinkering Tinkering in the Generation of Technological Novelty Two meanings of tinkering : 1) Bricolage (François Jacob s Evolution and Tinkering ), opportunistic use of whatever is at hand. 2) Exploratory, heuristic experimentation. Not to answer why, but to discover how things work. In the invention of the triode, lack of knowledge of the why did not prevent De Forest from discovering how the insertion of the grid created new useful functions. Tinkering is important both in experimental science and in the creation of technological novelty, but in the search for invention, tinkering is no longer subservient to the generation of conceptual knowledge. It attains its highest fulfillment in bringing into existence new artifacts and processes. The invention of the triode is an archetypical example of this kind of achievement. To Conclude This presentation is a highly abridged and incomplete version of my written paper. I hope that after hearing this sketchy talk some of you will be sufficiently intrigued to read the original argumentation in the article, available at and_tinkerers.pdf The last two sections of the paper examine the role of tinkering in technological research in connection with two issues: Tinkering conceived as a non-conceptual inferential abduction. Tinkering as a practice for accessing tacit knowledge (in Polanyi s sense). 8