Review: Einstein's Clocks, Poincaré's Maps

[Peter Galison. Einstein's Clocks, Poincare's Maps: Empires of Time. New York: W.W. Norton & Company, Ltd., 2003.]

This is a book about a lot of different things.

On the most basic level, it is a book about a question: What exactly do we mean, what can we mean, when we say that two things that are distant from one another are happening at the same time? A surprising number of rather important things depend on how we can and do answer this question.

This is a book about physics. The standard answers to the question above shifted in the late nineteenth and early twentieth century. Originally, it was widely assumed to be related to an absolute notion of time (a "universally audible tick-tock," in Einstein's words), a true time that ticks away in the background of the universe wherever and whenever you are. Not long into the twentieth century, however, it became clear that this was rubbish. Einstein's special theory of relativity brought together an idea originally proposed by Galileo -- that all uniform motion can only be defined in terms relative to other uniform motion and not with respect to any absolute frame of reference -- with the rather surprising fact that the speed of light is always experienced as being the same no matter what your state of motion or frame of reference. One of the consequences of this is that "two events happening in two different locations that occur simultaneously to one observer, may occur at different times to another observer." In other words, simultaneity, rather than being an absolute property, is something that can only be understood via some sort of conventional procedure. Though the theoretical breakthrough that rocked the scientific world's understanding of time happened in 1905, the practical necessity of some sort of agreed upon convention to establish simultaneity had long been recognized in practice by those who actually mucked about with clocks and railway schedules and longitude. At the time that Einstein published his famous paper, Henri Poincaré had long been involved in both practical work and advanced theorizing that included a recognition of this particular insight but that managed to scrupulously avoid the final, fatal step of dispensing with absolute time, keeping alive certain theoretical artifices that kept continuity with previous approaches to physics and with Poincaré's particular understanding of scientific intuition, but that had no basis in the experimental world.

This is a book about technical developments. Determinations of simultaneity have everything to do with the creation of standard times, the transition from each clock having its own time to each city and town having its own time to today's system of universally coordinated time zones. Such developments could only occur as the technology developed to allow them to occur, originally systems of steam and hydraulics, but much more effectively the telegraph and later the wireless. The convention involved broadcasting signals from one point to another and back again and accounting for how long they took to travel. This could allow clocks at a distance to be accurately set to the same time (within bounds of error that have sunk to mere billionths of a second today). And since determinations of time differences are also critical for determinations of longitudinal differences, these developments were centrally involved in developing accurate and unified maps of the globe.

This is a book about philosophy. If that statement leaves you scratching your head, there are lots of really cool books out there that talk about the interface between physics and philosophy and/or mathematics and philosophy. This is one of those rare books that I am not reading for work -- it was a gift from someone who I believe recalled that I at one time read quite a few such books. I don't read many any more, as a rule, but was glad to do so in this case. (As an aside, one of the most important to me of those that I read many years ago was Douglas Hofstadter's Gödel, Escher, Bach. Check it out.)

This is also a book about two men. As the author observes, there have been too many biographies written of Einstein and too few of Poincaré, so he devotes a bit more attention to the latter. Still, you do get a picture of the brilliant, confident young student and then patent clerk that was set to turn physics on its ear. You also learn a great deal about Poincaré, a member of the French scientific and technical elite who was approaching the end of his career just as Einstein was beginning his.

Second most interestingly of all, this was a book about all of these things, and how they interweave. It was actually quite a novel (or at least novel to me) approach to telling history, in that it mixed together biography, intellectual history, and material history. It also made the important point that this mixy complexity was not just about choices in storytelling but that it actually reflects the various toings and froings of the historical transition on which the book focuses, with shared ideas and personal creativity and technological advances and bureaucratic imperatives weaving together to result in the history that actually occurred. To be honest, I'm not in complete agreement with how he contextualizes this rather interesting bit of complexity. While I'm sure this example is a particularly interesting one for the ways in which things mix together, the way he describes it makes it sound rather more unusual than I suspect it to be. I would be willing to bet that most change of this sort happens that way. And even as he demonstrates that they are not, in fact, as distinct as our modern commonsense and traditional approaches to history would tell us, he still preserves the distinction between mind and body, intellect and application, thinking and doing, science and technology, rather than recognizing that all fall within the purview of a more unified understanding of doing. And, finally, perhaps in an effort to coin a phrase that might catch on and be used in histories down the centuries, he describes this complex interaction of spheres and scales as "critical opalescence." Uh-huh. Clever, yes, but trying a little too hard, I think.

The most interesting part of the book for me, and one that received notice in passing but was never really the focus, was that despite its billing as a history of ideas and technology, it is also a history of the development of one particular critical component of capitalism and imperialism. You can't control time and space if you can't keep track of them, and you can't have integrated relations oriented towards making profit without agreed upon standards for them. In fact, it brought to mind the particular way that Dorothy Smith talks about these things, as "ruling relations." One aspect of that approach is that it avoids treating capitalism (or whatever) as a monolithic blob, but rather emphasizes that it is a complex of relations that had a concrete beginning and is sustained on a daily basis by ordinary people doing concrete things, and that in order to create change we must understand the parts, the actualities of the relations that constitute it. What we tend to reify as "capitalism" requires in its advanced form, for example, standardized, mutually interchangeable systems of measuring length. This was not something that just happened by accident. In fact, there were detailed negotiations, a procedure decided, and then a rather portentious ceremony in Paris some time in 1889 to inaugurate the universal metre with which we buy cloth and design precision machine parts today. This social production of conventions that feel invisible to us today is an aspect of the main focuses of the book, too, around the development of a global time system and ever more precise mapping and so on. It was crucial in the era under study, because it was a time of military tension, a rush to include every last inch of dry land on the planet in one or another European empire. It was also a time of crucial shifts in the organization of economic activities. Conventions of time and space were very important to turning the troops out as fast as possible, knowing where your ships should sail, and making sure that conventions of production that had developed locally and nationally were integrated seamlessly together so that everyone (which is to say, all owning-class European men) could maximize their profit. And all of these conventions are just as crucial to the relations of ruling that govern us today.

Alas, as I said, mentioned but not dwelt upon.

In any case, this is an interesting book with an interesting approach to history. I was at times a little bit disappointed in the writing -- he's a clever wordsmith and tells a good story, but I felt he belaboured some of the analysis a little bit. But I am quite glad it came into my possession at a time when I had no work-related books waiting in the queue.

[Edit: For a list of all book reviews on this site, click here.]