Anthony's+Book+Review

__Einstein’s Clocks, Poincaré’s Maps: Empires of Time__ by Peter Galison highlights the political, technological, and philosophical factors that lead a young Bern patient officer published “On the Electrodynamics of Moving Bodies” in 1905. That young Bern patient officer is of course Albert Einstein and that paper is what has become known as special relativity, the paper that turned physics upside down. This book is not a review of the 1905 paper, however it is a summary of the attempts to standardize, synchronize, and decimalize time, and especially about the works in these fields by the great French mind Henri Poincaré (I say mind because Poincaré made important contributions to the fields of mathematics, physics, philosophy, and map making, so to sum him up as only one of those is an understatement), and how this debate over time lead Einstein (and in some ways Poincaré as well) to develop the theory of special relativity. This book is a good read for anybody that can think about things in ways you are not use to. I say this because much of the talk about time in this book is very different than the time we have today (more on that to come). Galison opens his book with a quick summary of the special theory of relativity, especially examining the ideas of time, simultaneity, and clock coordination. He also goes on to introduce Henri Poincaré starting with his college years. Poincaré attended the premier university in France, the Ecole Polytechnique. Aside from being the top school in the country, it also had unique way of teaching its students. As Poincaré put it “’There it is…that factory stamp that I was looking for; our physicists, our mathematicians are all a bit mechanicians’” (p. 49). This would prove to be a major force in Poincaré, driving his train of thought that would lead him to all his great discoveries. After graduating as valedictorian, Poincaré moved to the Ecole des Mines, where his interest in mine engineering would never fade, all the way up until his death. Poincaré’s great mathematical work began soon after his time in the Ecole des Mines. The work that put his name on the map was his essay on the three body problem, which was a problem in physics where trying to explain the motion of three bodies in relative motion with each gravitationally attracting each other is extremely complicated. Poincaré solved the problem with a novel idea of asteroids punching holes in a piece of paper along a stable pattern. Shortly after the essay was submitted, Poincaré learned there was a problem with his math, and recalculated it and came to the conclusion that the solar system was not stable as shown in his last essay, but in fact a system of chaos. It was this essay that truly launched Poincaré’s career. Galison then moves the late nineteenth century, when time was one of the most important topics of the day. It was during this time that the ability to synchronize clocks became an easy task. Failed attempts with air run devices lead to the distribution of time being extremely difficult. The problem was that each town measured its own local time, each country measured its own national time, and each railroad company had its own conventions. The problem came down to which one to use, and how to set all clocks off of this. Enter the telegraph cable, which was capable of sending messages to great distances very rapidly. This electrical technology was used to tie all clocks in a specific area to one great clock, and then send the time along the cables to any all clocks that wanted to be synchronized to it. Every country synchronized their clocks with this general principle, but not one international standard could be agreed upon. After international decimalized standards were set on the meter and the kilogram, thus founding the metric system, the debate over how to standardize time took over. With electrical and telegraphic technology just beginning to flourish, everyone realized that this seemingly instantaneous systems were perfect for sending time from one place to another. Not only could clocks all be set to the same time with ease no matter how far apart they were but also, the most precise measurements of longitude could now be acquired. Once transoceanic telegraph cables were perfected, groups of scientists raced around the globe, setting up portable telegraph and astronomy stations to determine the local time, and relate that to the central time of their home country, and thus plotted longitude easily and more rapidly than ever. Poincaré was had a huge part in this, as a high ranking official in the French Bureau of Longitudes. Yet, as Galison goes on to explain, the debate raged over where to set the zero line of longitude (the prime meridian), and just how will we measure time. The Americans and British favored the Prime Meridian run through Greenwich, and the world divided up into time zones (like we have today), while the French (if they couldn’t have Paris) wanted it to run through a neutral point, say the Bering Strait. An international committee decided that the zero line would in fact run through Greenwich, but left the door open for another French idea, as long as they could refine it. After applying a perfectly rational decimalized system for measuring length (the meter) and mass (the kilogram), the French wanted to apply the same ideas to the measure of time and the measure of the circle. According to Galison, the French claimed that 24 hour day and 360 degree circle were irrational and needed to be standardized like mass and time. The French Bureau of Longitudes set a commission to decide if France would stick with old system, or adopt a new decimalized one. The commission’s secretary was Poincaré. The question was how many parts to divide the circle into, thus standardizing time (arcs of a circle are related to seconds). There were five main ideas about how many parts to divide the circle into Poincaré presented to the committee, 100, 200, 400, 240, and 360. Poincaré suggested 400 because it had the easiest conversion factors. However, after strong opposition from scientists, telegraphers, and sea navigators, the old “irrational” system was left in place. After his attempt to decimalize time, Poincaré again returned to longitude. During this time, Poincaré published a work entitled “Measure of Time.” While studying transmission of time through telegraph cables to further the precision of science, Poincaré wrote down an important idea. As Galison put it “He insisted, in the most celebrated lines of the essay, that in the synchronization of clocks one had to take the time of transmission into consideration” (p. 183). In doing this, Poincaré was redefining simultaneity as nothing more than coordination of distant clocks. Poincaré’s work on time continued to be ground breaking. He went on to speculate that was no such thing as absolute time, as Newton had believed. Poincaré went on to say that the idea we call simultaneity is and only can be defined by electronically linked clocks, not by some absolute measure of time. It seemed that Poincaré was so close to developing special relativity, that all he needed to do was write those two words down. However, Poincaré soon became influenced by the ground breaking work of H. A. Lorentz, who had done work on Maxwell’s theory of electricity and magnetism, claiming that they were states of an all present ether. The only problem was, no one could find it, because no one could detect Earth’s movement in it (and it had been know for ages that all movement is relative), and experiments showed that the ether was not moved by the Earth. Lorentz then came up with an amazing theory that all objects moving through the ether contracted in their direction of travel. He also went on to say that there was one true physical time “ttrue” which could be used for objects at rest in the ether, and a “tlocal” that would represent a body as another fictional body at rest in the ether. Poincaré went on to simplify this, by saying the “tlocal” was the time clocks showed in a moving frame of reference, because depending on the direction of travel the speed of light (which carried the time signals) would be speed up or slowed down by an “ether wind.” This theory of Lorentz and Poincaré even included the idea of relativity. These two men had seemingly changed the way physics and time keeping would be done forever. However, not all was perfect with this grand new theory. Before going into the problems with the new theory, Galison backtracks about ten years to tell the story of the other man whose name is in the title of the book; Albert Einstein. Galison begins by contrasting the two, Poincaré the well established French intellect that was changing the world of math, physics, and map making, and Einstein, the young German who had just recently graduated and was struggling to find a job. During this time he put out an ad that he would tutor anyone in physics and mathematics. Two students, Maurice Solovine and Conrad Habicht, took Einstein up on the group and formed the informal discussion group “Akademie Olympia” where the trio discussed philosophy and… just about anything that interested them. One of the most influential pieces on Einstein was Ernest Mach’s writing on the notions of absolute time and space, which lead Einstein to find problems with Newton’s works. Also was John Stuart Mill’s logic which, as Galison describes, “…cautioned against ‘the prevailing hypothesis of a luminiferous ether.’” This time would heavily influence Einstein’s later works. The next major influence on Einstein’s work was his first real job, a patent officer in Bern. There he quickly became a very well respected patent reviewer, quickly moving up the ranks. Einstein got the job just as the clock synchronization boom was taking hold in Switzerland. He spent most of his days in the office reviewing clocks and how to synchronize them. Despite not having shown any interest in clocks before entering the patent office, they were now his life. Then suddenly, in the middle of 1905, in the midst of all these time synchronizing patents, it dawned on Einstein. Thus, the theory of special relativity was born. Like Poincaré, Einstein’s theory redefined simultaneity using electronically linked clocks; however, there was one major difference. Einstein rejected the ideas of local and true time and the idea of the ether all together. He also stated the speed of light is constant, no matter what, and cannot be affected by anything including an “ether wind.” Now, there was no such thing as time, only times relative to frames of reference. To sum it all together, Galison compares and contrasts the two men who had redefined time. While Poincaré viewed Einstein’s lack of mechanics in his work next to sinful, he greatly respected Einstein’s contribution to physics. Einstein had a less favorable opinion of Poincaré however. After a meeting at the Solvay Conference in 1911, Einstein said “’ Poincaré was simply negative in general, and, all his acumen notwithstanding, he showed little grasp of the situation’” (p. 299).Despite this, the two will forever be linked for their work on time. While Einstein receives all the credit for the theory in mainstream science today, one cannot over look the work of Poincaré. This book is full of information. Galison did an amazing job of researching all the stories and events he put in this book, and after reading you feel as if you have a deep understanding of the difficulty with time in the late nineteenth and early twentieth century. However, the book is a little long winded. Galison often goes on rants about stories only slightly connected to the rest of the book, and are probably do not need to be included for the reader to still have the full grasp of what was going on during this time period. None was this more evident than the story of how France, lead by Poincaré, tried to advance the use of radios. While a fascinating and historically important story, it has nothing to do with the main theme of the book, especially since it is in the chapter describing the work of Einstein. Also, Galison makes many time jumps, telling a story to its completion, and then going back in time to start a new one. However, despite all these shortcomings, the book is still a very interesting read for anyone with interest in the subject.