A Paradox Concerning Scientists and History

by David Kordahl

I’ve been thinking again about the relationship of scientists to the history of science. Lorraine Daston, the historian and philosopher of science, was recently interviewed for Marginalia, where her interviewer asked a strongly worded question. “Scientists are—I don’t want to put it too provocatively—but frankly they’re afraid of the history of their own discipline. What do you think that means?”

Daston was not quite willing to put all the blame at the feet of scientists. Historians of science, she remarked, have become more specialized, making their work less useful to scientists. Likewise, philosophers have failed to “remake of the concept of truth that does justice to the historical dynamism of science.” But then there’s the scientists themselves, who “consider almost anything which is not within their discipline, including other sciences, to be blather. So, there’s quite enough blame to go around in terms of explaining […] this impasse of mutual incomprehension.”

When this interview was released, it prompted some online chatter. Some scientists reading the interview did not see themselves in Daston’s characterization, since scientists do not, in general, consider themselves uninterested in the history of science—quite the opposite. The problem, for such history-interested scientists, was of approach rather than content.

To explore the basic distinction between “science history for scientists” and “science history for historians-and-philosophers-of-science,” I’ll use two complimentary books. Einstein’s Fridge: How the Difference Between Hot and Cold Explains the Universe, out last year from the science writer Paul Sen, exemplifies the former approach, where history provides a narrative scaffold to lead us gently toward our modern scientific theories. Inventing Temperature: Measurement and Scientific Progress, the 2004 work by the historian and philosopher of science Hasok Chang, is a classic example of the latter, where history is used as a proving ground to show that science and its history is more complicated than most scientists care to admit.

The title of Einstein’s Fridge gives you a good idea what you’re in for. You already know Einstein, and the anecdote about how he and Leo Szilard once designed a refrigerator is an amusing side quest in the long human quest from ignorance to knowledge. New characters bring new concepts with them, always pushing the story toward our present understanding, with most of their wrong turns edited out. When we meet Sadi Carnot, in Sen’s telling, it is to explain how Carnot could arrive at an accurate understanding of the efficiency of heat engines, despite his incorrect belief that heat was caused by a substance called caloric. When we learn about James Joule, it is to describe his experiments that introduced the notion that heat is a special type of microscopic motion.

And so the list goes on, through Herman Helmholtz and Rudolf Clausius, James Clerk Maxwell and Josiah Willard Gibbs, Ludwig Boltzmann and Albert Einstein…all the way up to Jacob Bekenstein and Stephen Hawking and black holes. Each hero arrives into the story to push us up one level of enlightenment, up toward our contemporary understanding of The Truth.

Inventing Temperature goes in the opposite direction. Chang spends much of his account of thermal history discussing forgotten historical controversies, some of which were never resolved. After each historical discussion, he includes a more abstract exploration about what the episode can teach readers about the abstract nature of measurement and scientific progress.

For instance, in the first chapter, “Keeping the Points Fixed,” Chang discusses early difficulties in the standardization of temperature. Substances like mercury tend to expand as they are heated, so putting mercury into an evacuated glass tube at the very least gives you a thermoscope, which can distinguish which objects are relatively hotter or relatively colder. But making a genuine thermometer, which goes beyond mere hotness rankings to provide a quantitative measure of temperature—by mapping hotness, that is, to a number—proved significantly more difficult.

The temperature scales in broad contemporary use are benchmarked via the freezing and boiling points of water. For instance, at standard atmospheric pressure, water freezes at 0º C and boils at 100º C. But such definitions ran into difficulties once scientists found that water could be both superheated and supercooled. Superheated water was methodically rid of all its bubbles, which allowed it to become hotter than water’s usual steam point before boiling. Supercooled water was isolated in perfectly dust-free flasks, which allowed it become colder than water’s usual crystallization temperature without freezing.

Did these cases invalidate the notion of a “fixed point” for temperature? Maybe so, but they did not mark the end of water-validated thermometry. Most hot water, after all, has bubbles, and most cold water is near dust. As Chang writes, “the theme […] is not the preservation of fixity by random chance, but its protection through a serendipitous meeting of the epistemic need for fixity and the natural human tendency for carelessness.”

Einstein’s Fridge and Inventing Temperature are both written for science-literate audiences, and both books have their uses. Einstein’s Fridge is good for students who want a narrative mnemonic for the big ideas of thermal physics. Inventing Temperature is good for experts who want to pull a bit at the loose threads that may lead to further unraveling.

But what about the “impasse of mutual incomprehension” that Daston mentioned? This, it seems to me, has less to do basic historical claims, and more to do with a fundamental disagreement about what sort of enterprise science is.

To make an overly broad generalization, philosophers like Daston and Chang work in the shadow of Thomas Kuhn (1922-1996), who taught philosophers of science that one way to understand the nature of science was to look at its history. Kuhn wrote in the opening of The Structure of Scientific Revolutions (1962), “History, if viewed as a repository for more than anecdote or chronology, could produce a decisive transformation in the image of science by which we are now possessed.”

And what does this history tell us? Well, from Kuhn’s perspective, textbook histories a la Sen are essentially comforting myths, ways for scientists to imbue their work with meaning. When scientific work becomes difficult and technical, as it often is, scientists are able to think back to the history stories, putting their work, which often amounts to very little, in the context of a grand tradition. Science history for scientists, in this view, functions as self-help, as motivational propaganda.

In other words, when scientists dislike the philosophers and historians who follow Kuhn, they have good reasons. Even leaving the unflattering caricatures aside, many scientists still generally think of themselves as chasing The Truth, while historians and philosophers of science more often see scientists as working together to fish for serendipitous accidents that somehow prove reliable.

Of course, I’m overstating things for effect, and I should remark that, despite what I’ve said so far, I’m generally sympathetic to Kuhn and his followers. When Chang shows over and over in Inventing Temperature that “decisive” experiments were far less decisive than their promoters claimed, I believe him. In their rigorous skepticism, philosophers and historians of science have the upper hand. But the goal of science is not just doubt…and here we find our paradox.

Suppose historians and philosophers of science—HSPs, to explicitly construct a strawman—are right. Suppose that science doesn’t get at the deep essence of any phenomena, and that science history is filled with abandoned veins of gold. Given this, whose work would a benevolent mentor recommend to a student scientist: the HSP Chang, or the motivational guru Sen?

Though Chang, in this thought experiment, is more nearly right, the student may still benefit more from reading Sen. Why? Because in Einstein’s Fridge, Sen gives the impression that empirical study can pay off. No doubt Chang would insist that Inventing Temperature is also a story of empirical studies that paid off, but science students need all the encouragement they can get.

I find myself, with this, circling back to religious analogies—to Pascal’s wager, or to Kierkegard’s leap of faith—where they may not be entirely warranted. But there does seem to be a connection. The belief in a sturdy framework, whether in religion or science, can be enormously helpful to young investigators as they launch themselves toward unknown depths. Though my own attitudes tend toward agnosticism in all things, this may not be the best attitude for someone aiming to make empirical discoveries. It may be that “mutual incomprehension,” too, sometimes has its uses.