Science Secrets
Page 23
Even physicists add fanciful details. Michio Kaku is a professor of theoretical physics at the City University of New York. He is also a bestselling author of books that popularize science and a host of television and radio shows. Here is Kaku's account of Einstein and the clock tower:
Einstein was depressed, his thoughts were still churning in his mind when he returned home that night. In particular, he remembered riding in a street car in Bern and looking back at the famous clock tower that dominated the city. He then imagined what would happen if his street car raced away from that clock tower at the speed of light. He quickly realized that the clock would appear stopped, since light could not catch up to the street car, but his own clock in the street car would beat normally…. He had finally tapped into “God's thoughts.”26
Here, the story is portrayed as Einstein's own recollection. Yet, every sentence is complete fiction, except for one simple phrase: “his thoughts were still churning in his mind when he returned home.”
Kaku's elaborate story has been picked up by various writers. It was echoed by political commentator George Will.27 It has been repeated in various books on physics, economics, scientific literacy, and creative thinking.28 Also, this story about the tram and the tower has promptly entered into tourist books of Switzerland. For example, one book from 2006 states: “It's said the clock tower helped Albert Einstein…. The great scientist surmised, while traveling on a tram away from the tower, that if the tram were going at the speed of light, the clock tower would remain on the same time, while his own watch would continue to tick—proving time was relative.”29 The story has also entered into educational books.30 I much expect, someday soon, to come across a schoolbook on physics that will duly mention the supposedly chronometric roots of Einstein's relativity. It might be a brief human interest sidebar. Maybe it will have a nice picture of an old clock tower, like the drawings of Galileo's legendary experiments from the Leaning Tower of Pisa. And fine, maybe it will help students to become more interested in the history of physics and its relation to society, which would be good. Already, I find an advanced textbook on quantum chemistry that tells a story about how Einstein was influenced by a tram and a clock. It stops short of referring to any tower: “Einstein recalls that there was a clock at a tram stop in Bern. Whenever his tram moved away from a stop, the modest patent clerk asked himself what would the clock show, if the tram had the velocity of light. While other passengers probably read their newspapers, Einstein had questions which led humanity on new pathways.”31
I read the growing echoes of the myths about towers and trams with a mixture of amusement and discomfort. It is revealing to see how many writers don't bother to check the truth of a story before they repeat it. I guess that they just trust their sources. And it is entertaining to see how they bury facts beneath layers of thoughtful but needless conjectures. It will be interesting to see what forms these tall tales will take, if they reach schoolbooks, standardized tests, and children's story books. But I also look forward to a time when writers bypass this cloud of fiction to get back to the task of finding out what really happened in the past.
13
The Secret of Einstein's Creativity?
MANY theories have been proposed to explain Albert Einstein's creativity. For example, Peter Galison argued that Einstein's relativity arose from the fruitful intersection of three fields: science, philosophy, and technology. Although Galison wrote more about the technological side, he acknowledged that science and philosophy were very important too. In physics, technology, and philosophy, people were concerned with notions of time. There's something pleasant in the idea that the intersection of these three fields generated Einstein's conceptual breakthrough. But one reviewer of Galison's book fairly complained: “The inevitable question is then to decide what weight to attach to these different factors, and Galison refuses to address the matter.”1
And what about art? In 2001, Arthur I. Miller argued at length that special relativity arose from the intersection of four fields: science, philosophy, aesthetics, and technology.2 Was the influence of each field equally great, about 25 percent, upon Einstein's creativity? The problem is that then we are chopping up creativity equally among certain academic disciplines. Is that fair? What about economics? Why don't we include it and assign each field a 20 percent influence? But perhaps the influences were not equal. The historical question—how do we ascertain the actual roots of someone's creativity, rather than just the plausible imaginable roots?
Einstein lived for fifty years after 1905, and he became ridiculously famous. Friends, strangers, coworkers, relatives, reporters, writers, biographers, psychologists, and historians all asked him about the roots of his creativity. “How did you do it?” How did he come to think of the relativity of time? Despite plenty of inquiries, interviews, letters, and casual questions, Einstein never mentioned any influence from art or from any timing technologies at the patent office. And neither did any of his coworkers. Instead, Einstein, his friends, and his peers pointed to several other factors and influences.
For example, Michele Besso was Einstein's close friend since 1897 and coworker at the patent office since 1904. Besso had trained as a mechanical engineer and was experienced with electrical technologies. Einstein acknowledged that Besso helped him to clarify the thoughts that resulted in his special relativity, with critical discussions and valuable suggestions. Hence Besso was very well positioned to judge whether patents or chronometric innovations influenced Einstein's path to relativity. Yet in none of their extensive correspondence, written over decades, did either of them mention any such thing. In a letter written in 1947, when Besso was seventy-four years old, he actually asked Einstein how he had come to think of clocks and measuring rods in relativity. It was an opportunity to state or insinuate any influence from timing technologies, yet Besso did not. Instead, he asked whether perhaps Einstein's early reading of a book by Ernst Mach, following Besso's suggestion, had been at the root of Einstein's thoughts about clocks and measuring rods.3 Mach? No, replied Einstein. Now he had a perfect opportunity to point to clocks and clock towers. But again he did not allude to any technological issues, nor even to art. He acknowledged a great influence of Mach on his intellectual development in general, but he noted that his reading of the philosopher David Hume, whom he discussed with Solovine and Habicht, had been of greater importance in thinking toward relativity.4
Accordingly, John Stachel, founding editor of The Collected Papers of Albert Einstein, has argued that Hume's notion of time, in particular, may have influenced Einstein.5 But Stachel acknowledged that this was essentially a conjecture since Einstein did not specify Hume's views on time, just acknowledged the influence of Hume's critical outlook in general.
Over the years, writers have proposed many other hypotheses to try to explain Einstein's path to relativity. Besides Hume, Mach, patents, Mileva Marić, and aesthetics, writers variously have conjectured that Einstein was crucially influenced by the physics of H. A. Lorentz, experiments on light, the writings of Poincaré, and even by reflections on God.6 Thus Stachel has noted that there is still no consensus on the history of special relativity. More broadly, philosophers have variously attributed notions of relativity to many earlier authorities, including even the alluring Pythagoras.7 It seems as if the roots of relativity are not a matter of history, but of personal preference.
Several years ago, some historians met at a centenary conference on Einstein. One speaker was giving his new account of how Einstein reached special relativity—what, allegedly, were Einstein's series of steps. Two or three times during his talk, he punctuated his statements by loudly and pointedly saying “John Stachel,” as if to emphasize that Professor Stachel should agree with some particular point he was making, but didn't. And Stachel remained quiet, he was sitting behind me, and he scribbled something on a sheet of paper and handed it to me. It said: “What song did the syrens sing.”8 There's no consensus. Trying to figure out precisely the thoughts of one guy back on
a spring day in 1905 seems to be unsolvable—like specifying which songs were sung by mythical mermaids. But some writers are quite sure that their favorite way in which Einstein may have reached special relativity was in fact the way it happened.
One possible reason why historians have not converged on a shared explanation is that some accounts are too reflective of the historians themselves rather than the subject. Also, many writers tend to neglect participant testimony, such as what Einstein himself said about how he made his conceptual breakthrough. A common reflex is to say that a participant's answer, whatever it be, would likely be irrelevant. Some authors lie, or they forget their seminal thoughts, or they are quite unaware of their essential motivations. Such dismissive expectations are useful as a historical strategy because they shove aside the authors' presumed authority to explain themselves, such that the historian or commentator instead can seize that right with all the benefits it entails.
Regardless, suppose we care enough to listen to the dead. What if we could ask Einstein, today, why was it you who formulated the theory of relativity? What would he answer? Actually, we have a document that responds directly to that question. Einstein once explained to another physicist, James Franck:
When I asked myself, how it came to be that I in particular found the theory of relativity it seemed to me to lie in this: The normal adult person does not think about space-time problems, he has already done all that there is to think about that in early childhood. By contrast, I was so slow in my development that I first began to wonder about space and time when I was already grown up and hence naturally I penetrated deeper into the problem than a child.9
Here we have a documentary trace pertaining explicitly to the actual roots of Einstein's creativity. We might place it under the banner of developmental psychology.
There may, however, be doubts over Einstein's quotation. Was he serious when he said this? Did he really say this? It is not a statement from Einstein's hand but a transcription by Franck in a letter he sent to Einstein's biographer Carl Seelig in 1952. If Einstein did say this, when did he do so? We don't have the date, so even if he said it, in the 1940s for instance, that does not mean that it really described the situation in 1905, when he was formulating his theory of relativity. There are also questions about the content: Did Einstein really develop intellectually slowly? Did he really think in some childish way about notions of time in 1905?
To analyze this quotation historically, let's trace backward, against chronology, to find its apparent roots in the distant past. Part of the exciting thing about history is the research process by which one piece of evidence leads to other earlier bits, so I want to convey that process of gradually unveiling earlier layers of documentary facts.
Regarding the legitimacy of the quotation: Einstein approved it. We know so because he made a detailed list of corrections to Seelig's biography of him after it was published, and he kept this quotation.
Given that Einstein said this late in his life, can we trust that it really happened? Did he, for one, “develop so slowly”? Luckily, there are sources that attest to this. For example, when Einstein was a boy he began to talk so late that his parents were worried that he was developmentally challenged. According to his sister, for the young boy: “Normal childhood development proceeded slowly, and he had such difficulty with language that those around him feared he would never learn to speak.”10 Eventually he did speak, but at the age of five, according to his parents, he was still phlegmatic and distracted.11 He spoke, but with a strange habit: “Every sentence he uttered, no matter how routine, he repeated to himself softly, moving his lips. This odd habit persisted until his seventh year.”12 We also know that at the age of eight or nine he was shy and unsociable.13 Only much later, ten or twelve years later, did he become social and talkative. But in school, Einstein “was considered backward by his teachers…. his teachers reported to his father that he was mentally slow, unsociable.”14 Thus, several pieces of evidence substantiate the claim that Einstein developed slowly as a child.
What about Einstein's claim that he analyzed notions of time like a child? It is reminiscent of Jean Piaget's work on child psychology. In 1946, that Swiss psychologist published his book on The Development of the Notion of Time in Children. So it might seem appropriate that if Einstein's words are from the 1940s, then he might just be echoing ideas of the time, as what Piaget called “genetic epistemology” was then pretty popular. It turns out, however, that the influence was the other way around.
Back in 1928, Einstein was invited to preside over the International Congress on Philosophy and Psychology held in Davos, Switzerland. At the time, Piaget was chair of psychology, sociology, and history of science at the University of Neuchâtel. At the conference, Einstein asked Piaget's group to investigate the following questions: “The subjective intuition of time, is it primitive or derived, and intermixed, or not, to that of speed? Such questions, do they present a concrete meaning in the analysis of the genesis of notions in a child, or well the construction of temporal notions: is it finished before being translated to the plane of language and conscious reflection?”15 It was only after that suggestion, according to Piaget, that his group began to research the development of notions of time in children, resulting in Piaget's book of 1946.
Returning to Einstein's explanation of his creativity, he claimed that there was a kind of developmental delay, a childish thinking about basic problems, that led him to relativity. Is it true that he thought about problems like a child in 1905, when he was twenty-six years old? Moritz Solovine, a close friend of Einstein's and one of the three members of their informal discussion group from 1902 until 1905, recalled that at that time: “In the examination of fundamental notions, Einstein employed with predilection the genetic method. He used it to clarify them by what he had been able to observe in children.”16 Solovine reported this in 1956. At first blush it sounds anachronistic, as if Solovine were projecting into 1905 the kind of work that arose only later: the psychological studies on children led by Piaget on genetic epistemology in the 1930s.
That is not, however, what Solovine meant by “the genetic method.” Because by 1900 when Piaget was not even five years old, the “genetic method” already was construed to investigate the formation of ideas and habits, and to replace static metaphysical presuppositions with scientific developmental statements.
This line of research was pioneered in the 1890s by American psychologist James Mark Baldwin. He performed systematic experiments on children, including his own daughter, advocating what he called “the genetic method.” Baldwin was a proponent of the experimental psychology coming from Germany, from the laboratory of Wilhelm Wundt, where he had studied. Baldwin was a professor of psychology at Princeton, a founding member of the American Psychological Association, and, in 1897, its sixth president. For Baldwin, genetic psychology was the new field of studying the mind—not as a static soul or substance with fixed structure and attributes, but instead as a growing, evolving entity. Baldwin argued that to begin to understand elaborate conceptions, one should begin by analyzing the relatively simple activities, behaviors, and movements of children; how they respond to their environment. Baldwin argued: “The study of children is often the only means of testing the truth of our mental analyses.”17
Did Einstein read any writings by Baldwin? We don't know; I have no evidence that he did. Yet at least there really was such a thing as “the genetic method” in 1905 when Einstein was formulating his theory of relativity.
Next, do we have any evidence that Einstein, on or before 1905, cared about making observations about how notions in children develop? Yes, but very little. In early 1902, Einstein's fiancée Mileva Marić gave birth to their daughter. When the baby, Lieserl, was just one month old in February 1902, Einstein wrote to Mileva: “Can she already turn her eyes well toward anything? Now you can make observations. I'd like to make a Lieserl myself sometime, it must be interesting! She can certainly cry already, but won't know how to lau
gh until much later. Therein lies a profound truth.”18 There is also a letter from Mileva Marić that refers to how children develop physical concepts. Her bright and thoughtful letter, from 1897, told him: “I do not believe that the structure of the human brain is to be blamed for the fact that man cannot grasp infinity; he certainly would if only in his young days, when he is learning to perceive, the little man wouldn't be so cruelly confined to the Earth, or even to a nest between four walls, but instead be allowed to walk out a little into the universe. Man is very capable of imagining infinite happiness, and he should be able to grasp the infinity of space.”19
Even if Einstein and Marić were unfamiliar with Baldwin's writings and observations on infants and children, was there anything similar in other writers' works? There are several significant leads. For one, prior to 1905 Einstein read with enthusiasm the works of Ernst Mach. Mach was the well-known Austrian physicist who actually had a strong interest in psychology. His interest in the development of general notions in our minds is one of the things Einstein admired. And Einstein later praised Mach for having been a scientist who “looked into the world with the curious eyes of a child.”20 (Friends and physicists made similar comments about Einstein.)
In 1886 Mach published his book, The Analysis of Sensations, which Einstein read before 1905. Through systematic research in physics, physiology, and history, Mach tried to resolve the traditional apparent conflict between the physical and the psychological, arguing that the fundamental elements of physics are sensations. Mach argued that “the aim of all scientific research” is the “adaptation of thoughts to facts” and that that process can be essentially observed in children.21 This resonates with Solovine's claim: “In the examination of fundamental notions, Einstein employed with predilection the genetic method. He used it to clarify them [such fundamental notions] by what he had been able to observe in children.”