As a historian of science and technology, I find one of the most instructive case studies on the impact of new technology on science to be the introduction of lens instruments after the year 1600. It’s easy to look back today at the advent of lens instruments, i.e. the telescope and the microscope, and assert their role in establishing modern science as we know it, but the value of such instruments actually took many years to be vindicated. Looking through those first telescopes and microscopes often left people skeptical that artificial equipment revealed new truths instead of new illusions. Why trust a radically new method that radically undermined a thousand years of belief, especially if you have inherited a tradition of distrusting new methods? I’m considering producing a podcast on this topic in Season Two, but for now, I thought I’d blog about my thoughts on the page…
Over the course of the 17th century, it is clear that scientific instruments played a fundamental role in converting the scientific methodologies of pre-industrial natural philosophers to a form that resembles those of today’s scientists. A prominent origin of modern scientific reliance on instrumentation can be traced to the practices of 17th century experimental philosophers. Practically all of the new scientific discoveries of the century, in fact, from those in geography and physics to those in astronomy and physiology, were made with the help of scientific instruments (Kent, Robert Hook and the English Renaissance, 97). These instruments extended human capacity to sense and interpret natural phenomena, allowing previously inaccessible scientific frontiers to be explored. This, in turn, helped cultivate a new ethos of progress, both scientific and material, in the philosophical community.
As some other historians of technology have noted, it is not surprising that the most important new instruments of the 17th century were designed to extend our sense of sight. “Sight is humankind’s strongest sense and by providing new tools with which to see an invisible world of tiny creatures, or to contemplate distant stars invisible to the naked eye,” 17th century experimental philosophers were equipping themselves with tools to harvest the lowest-hanging fruits of scientific discovery (Macfarlane, The Glass Bathyscaphe, 81). Galileo, Hooke, Newton, Van Leeuwenhoek, and other leaders of the Scientific Revolution all relied on lens instruments to help shift scientific authority from inherited common sense and dialectic to equipment-aided experimental observation. And, “unlike the esoteric ideas of Kepler,” for example, “the new phenomena that Galileo described were (ideally) accessible to all” (Friedel, A Culture of Improvement, 60). Likewise, the pictures in Hooke’s Micrographia would seem to automatically expand the intellectual horizons of philosopher and layman alike. But did they?
While these 17th century lens technologies ultimately catalyzed a revolution in scientific methodology, it must be noted that their early effectiveness, development, and application did not clearly presage this. Although Galileo achieved scientific fame with his telescopic observations, many of the technical problems that gave rise to image distortions in early microscopes and telescopes took decades to solve, and skepticism toward their utility and legitimacy as scientific devices persisted through at least the first third of the 17th century.
Early telescopes (then called spyglasses) were crude, presenting somewhat fuzzy images and a magnification power of no more than four. A pair of glass lenses, one convex and one concave, were positioned in a tube with apparently little awareness of optimal lens thicknesses, concavities and convexities, and spaces of separation between lenses. Not surprisingly, immediately after getting his hands on one of these primitive telescopes, Galileo began experimenting with its design. To increase its magnification, one of Galileo’s first steps was to alter the relative degrees of concavity and convexity of the two lenses, but in 1609 no one was making lenses to the specifications that Galileo needed (Van Helden, The Sidereal Messenger, 6). Artisans were trained to make lenses for spectacles, not scientific instruments. Thus, one of the most obvious challenges facing 17th century experimental philosophers who depended on lens technology was the requirement that they become lens technologists. “It is therefore no coincidence,” writes Alan Macfarlane in The Glass Bathyscaphe, “that the list of those who became lens-grinders overlaps so closely with the great figures associated with the scientific revolution.”
This double duty – working as natural philosophers and technologists – is part of what made the work of these men revolutionary. Their embrace of a new scientific methodology that relied on unfamiliar, problematic, artificial instrumentation, and their willingness to interpret the distorted images they saw with these instruments in ways that contradicted everything people believed, was historically exceptional.
As profound as Galileo’s astronomical discoveries were, Robert Hooke’s and Antonie Van Leeuwenhoek’s exploration of the microscopic scale of the world produced as much of an epistemological shock to 17th century Europeans. Both men’s observations with the microscope reinforced a growing European awareness of the inadequacy of traditional experience and common sense in providing an accurate understanding of the natural world. As was the case with Galileo’s Sidereus Nuncius, however, the sensational discoveries and scientific insights publicized by Hooke, Leeuwenhoek, and other 17th century microscope enthusiasts tend to overshadow the methodological problems inherent in their work that frustrated their early reception. Hooke suffered chronic lack of light in his observations, for example, and few were able to see all of the microscopic detail he claimed to see.
Technological momentum with scientific instrumentation only began to accumulate as the 18th century approached, when “the new knowledge that improved instruments enabled then fed back into further technical advance” (Macfarlane, 84). Only as experimental philosophers grew aware of the process of technological improvement did it become an expected source of future discovery and human progress, but popularizing that awareness was itself part of the work of the Scientific Revolution. As Hooke had to argue in Micrographia in 1665, “the World may be assisted with a variety of Inventions, new matter for Sciences may be collected… Tis not unlikely, but that there may be yet invented several other helps for the eye, as much exceeding those already found, as those do the bare eye.”
Instrument-aided experiment is integral to our image of modern science, but like a new theory, the epistemological validity of new technology took time to prove. The pioneers of instrumentation needed to engage in a process of displacing longer-established, instrument-free methodologies, which was itself revolutionary. They needed to persuade their tradition-bound peers to believe even the most unbelievable things seen through telescopes and microscopes, rather than discount those visions as instrumental deceptions.