| String theory as scientific imaginary, part 3 |
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| Written by Sean Miller | |
| Friday, 12 October 2007 | |
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The Science in a Scientific Imaginary Within a scientific imaginary, what is the significance of science, and in particular, string theory as a science? I will define science as a cultural institution—a collection of social practices that mediates interactions with an objective world. As a science, string theory consists of two basic components: an amalgam of mathematical formalisms and an imaginary that surrounds and sustains that system. Echoing the steadfast insistence of the theorists themselves, I have argued that the actual scientific practice of string theory consists in the manipulation of mathematics, an assertion to which both logical positivism and scientific realism would concur. Generally speaking, the professional culture of string theory subscribes to the maxim, attributed originally to Galileo, that the language of nature is best understood as mathematics.[45] Accordingly, the principle content of string theory—whatever truth-value it possesses—consists in its mathematical formalisms. As alluded to earlier, this is what positivists would call the context of justification, the proper field of scientific practice. Whatever images or exposition that occurs around the mathematics—for example, in a technical article—resides within the context of discovery. According to positivism, images—and whatever imaginary they comprise—play a fundamentally didactic role in the practice of string theory as science. Yet it is difficult to establish an obvious coherence within string theory as a science proper. As explored in the previous chapter, since its inception in the early seventies, there have been numerous versions of string theory: initially, it was understood to be a theory of hadrons, then of bosons, then of bosons and fermions. A string theory that incorporated supersymmetry—known as superstring theory—reached maturity in the mid-eighties. Within superstring theory, five distinct variations have gained credence—Type I, Type IIA, Type IIB, Heterotic O(32), and Heterotic E8 x E8. Each one of these five types can also be formulated in a multitude of ways, depending primarily on how the theorist compactifies the six extra spatial dimensions. Strategies of compactification include employing Calabi-Yau manifolds—of which there exist millions, if not billions—orientifolds, and orbifolds, to name a few.[46] Others, such as S. James Gates, Jr., have attempted to formulate superstring theories in four spacetime dimensions. With the emergence of M-theory in the mid-nineties, the multiplicity of string theories becomes even more compounded. As the previous chapter described, M-theory suggests that supergravity—a theory wholly distinct from string theory and one that, furthermore, possesses its own cornucopia of variations—represents one facet, along with the five previously mentioned superstring theories—of an overarching and inclusive ‘mother’, ‘matrix’, or ‘membrane’ theory. In the last chapter, I also alluded to the fact that neither M-theory’s creator, Ed Witten, nor the rest of the string theory community consider M-theory to be fully realized—it only sketches the limits of a coherent theory. Furthermore, M-theory is not a theory of strings, per se, but of branes. Strings become a special case of this more fundamental object.[47] More recently, string theorists have developed models that consider a cosmos where the extra spatial dimensions stipulated by superstring theory are not compact, but rather, infinitely expanded—giving way to various string theories where braneworlds exist within a multiverse or what they have come to call a ‘bulk’. Another braneworld theory that has garnered a great deal of attention recently is Landscape theory.[48] The theorists themselves are hard pressed to articulate an irrefutable scientific argument for the inclusion of this hodgepodge of theories, models, and configurations—all with varying degrees of distinctiveness—within some overarching aegis called string theory. In this sense, string theory as a moniker becomes largely a matter of convenience—and convention. What this heterogeneity suggests is that, while not science proper, as the string theorists themselves would define it, the imaginative component of the theory plays a significant role in its scientific practice. At the very least, for practical purposes, an overarching string theory imaginary plays a role in unifying these disparate versions into a functional whole. It supplies a basic container, so to speak, for theorists and lay audiences alike to amass a collection of images, ideas, and concepts according to varying criteria of inclusion. This imaginary, thus populated, affords its participants a space of possibility and interaction. The problem of string theory’s coherence is further complicated by the organization of high energy physics itself. In her ethnography, Sharon Traweek observes that the majority of string theorists must undergo upwards of fifteen years of specialized training before they earn recognition from the community as independent professionals.[49] While certain materials comprise what one could consider a pedagogical canon, the field is broad enough that different schools must necessarily emphasize certain aspects over others. The field is, in fact, so vast that string theorists are obliged to specialize even within string theory itself, at the expense of claiming authority in other subjects within the field. The number of years that a string theorist-in-training must invest before he or she (predominantly, he) is ‘up to speed’, increases with each passing year. Currently, many must commit to a few years of postdoctoral research to reach professional independence. [50] I point out this sociological context out in order to re-emphasize that the fractured organization of it professional practice exacerbates the multiplicity of string theory’s content as an imaginary. It would also be difficult to delineate precisely the boundaries between string theory—both its imaginative content and its professional practice—and the rest of high energy physics. Much interesting and important work in string theory takes place at the boundaries of the discipline. M-theory represents one example of this, involving, as it does, supergravity theory. Some theorists, such as Michio Kaku, have attempted to synthesize string theory with quantum field theory into what is known as string field theory. There is also an active field of inquiry that concerns itself with a holographic correspondence between quantum field theory and string theory.[51] The following are also hybrid fields: string theory cosmogony; string theory and mathematical physics, whose practitioners, Traweek writes, ‘concentrate on linking developments in mathematics with ideas emerging in particle physics’; string theory and phenomenology, done by specialists ‘who work at finding the best fit between data and existing theories [and who] may occasionally suggest experiments’[52]; and whatever recent syntheses string theorists might undertake with rival theories, such as loop quantum gravity or twistor theory. Within string theory, there are also two generally acknowledged moieties: model builders and theorists. Lisa Randall defines model building as ‘what physicists call the search for theories that might underlie current observations’. [53] Model building and theorizing represent different strategies for reaching a similar goal: model builders tend to work from observational data towards a formal structure whereas theorists tend to work from the formal to the empirical. But the distinction between the two approaches would seem to be more a matter of emphasis rather than a categorical difference. Both approaches accommodate a multitude of methodologies. The sociologists Martina Merz and Karin Knorr Cetina have observed that even the mathematics employed in string theory betrays a certain hotchpotch quality: Our [study] yielded layers of methodical policies, ‘ansätze’, tricks and other devices, which are piled into doing a theoretical computation. The policies, ansätze, tricks and devices were mutually embedded in one another within a sequential interactional system involving disembodied objects, several physicists and competing teams.[54] Again, this speaks to the multiple quality of a string theory imaginary, echoed here by Merz and Knorr Cetina in their description of ‘tricks and other devices’ being ‘piled into’ a ‘computation’, where they become ‘mutually embedded in one another within a sequential interactional system involving disembodied objects’ and the agents acting upon then, the ‘physicists and competing teams’. Merz and Knorr Cetina, of course, are associating the mathematics to social practice. But if the mathematics, the ‘tricks and other devices’ to which they refer also correspond to images in the expository paratext of string theory practice, whether technical articles or more informal forms of communication, then any imaginary that emerges from these texts would also exhibit a comparable structure. It would appear as an ‘interactional system involving disembodied objects’. To speak of the hotchpotch nature of doing string theory mathematical operations is then also to necessarily implicate its concomitant imaginaries. So, in defence of string theory’s coherence as one complete, contiguous whole, one is forced to confront a myriad of multiplicities on various planes—historical, sociological, formal, and textual. String theorists themselves would be the first to admit that what the theory most acutely lacks is a unifying principle in the way that Einstein’s theory of general relativity does, an example they most cite when discussing this mother of all problems in string theory.[55] A handful of intricately related equations, the Einstein field equations, codify general relativity into a coherent whole, which can be articulated in ‘plain language’ as a basic, readily intuited principle. This is the famous equivalence principle, which states that the force of acceleration and the gravitational force are the same. Traditionally reductionist physicists, such as Niels Bohr and Einstein, actively promoted such easily intuited principles as the litmus test par excellence for any theory’s legitimacy. String theory lacks its own equivalence principle; nor does it possess a concise and universal canon of equations, as general relativity does.[56] General relativity represents, in some respects, the apex of triumphant reductionism. Even so, general relativity contains its own imaginary—a complex of images that correspond to the theory’s mathematic expression, and which function in an expository, rather than a quantitative context.[57] What this suggests is simply that the imaginary that coincides with a given theory—whether, as I have considered here, general relativity or string theory—will, to a certain extent, reflect the relative complexities and ambiguities of that theory’s formalisms. Mathematical operations are highly precise and local: this calculation using one technique, that proof using another, etc. To stitch these local practices into a whole would necessarily require an imaginary—the sea surrounding and infiltrating the archipelago. As a branch of reductionist high energy physics, string theory, even while assuming its own unitary ‘endo-epistemology’, as Serres puts it, has a more difficult job in claiming scientific authority due to its all the more obvious multiplicity. Limiting oneself to only an examination of the textual, one is left to consider the extent to which an imaginary works to shore up this seeming lack of cohesion. If the real business of string theory professional practice consists in the manipulation and expression of mathematics, then the remainder, that part of the text that is not mathematics, is more appropriately understood in terms of imaginaries and the narratives that present them. Furthermore, it would be paramount to delineate the extent to which, in a given discourse, one can claim that the imaginary is, in fact, one imaginary, rather than a multitude of disparate or only tenuously related imaginaries. One must establish the extent to which a given imaginary can be said to cohere into a totality. This, in turn, prompts the question: if it is highly problematic to speak of even an individual string theory imaginary as more than hopelessly heterogeneous, then what are the conditions under which both the professional community and a lay audience has come to understand string theory as a string theory and not a cacophonous rabble of string theories, brane theories, M-theories, F-theories, Landscape theories, etc.? This proclivity to fill in the gaps between what are highly local scientific practices speaks to the significant role that a imaginary plays within a discourse that claims to be scientific or to be based on science. In this sense, I would argue that a scientific imaginary—a complex of images that references, with varying degrees of ambiguity, a self-professed scientific practice such as string theory—must necessarily betray a susceptibility to scientism. I want to clarify here what I mean by scientism, a word with strong ideological connotations. Originally in the first decades of the twentieth century, the term scientism functioned as a descriptive that was more or less synonymous with logical positivism. It engendered an optimistic anticipation that a strict execution of the scientific method would eventually lead to the full divulgence of nature’s secrets. Michael Shermer, a columnist for Scientific American, defines scientism as ‘a scientific worldview that encompasses natural explanations for all phenomena, eschews supernatural and paranormal speculations, and embraces empiricism and reason as the twin pillars of a philosophy of life appropriate for an Age of Science’.[58] The implication here seems to be that science, as a cultural practice, is monologic.[59] Science ultimately speaks with one voice and unifies a culture’s knowledge of the objective and objectifiable world into one coherent whole. Scientism assumes that there is only one empiricism, rather than a multitude of empiricisms, a congeries of methods for measuring and justifying that are specific to a given situation. These are difficult, if not impossible, to codify into one whole. It assumes that there is one monolithic reason, one categorical ur-reckoning, rather than a multitude of context-specific reasons. Bachelard is one of the first philosophers to call attention to this cultural phenomenon: ‘When one looks at science, what is immediately striking is that its oft-alleged unity has never been a stable condition, so that it is quite dangerous to assume a unitary epistemology.’[60] But it is Paul Feyerabend who argues most vociferously that, as far as the scientific method is concerned, the sole dictum is that ‘anything goes’: [W]e may say that the assumption of a single coherent world-view that underlies all science is either a metaphysical hypothesis trying to anticipate a future unity, or a pedagogical fake; or it is an attempt to show, by a judicious up- and downgrading of disciplines, that a synthesis has already been achieved.[61] I would argue that scientism as such can only work through an imaginary. Without a scientific (or, perhaps more appropriately, scientistic) imaginary, scientism would not be able to sustain the kinds of accretions and concatenations necessary for such a grand unification. I want to stress, though, that this argument does not in any way make any claims that would impinge upon the effectiveness of the scientific practices themselves. I am not arguing against string theory’s access to objectivity by means of reasons and methods, but rather, that in order to have such local practices cohere into a whole, one must necessarily resort to an imaginary. Pure concept, as defined earlier—whether in the form of mathematics or experimental data—alone will not serve. Furthermore, a scientific imaginary such as that of string theory would ostensibly have a special, heightened authority, insomuch as it is presumed to be predicated on the general authority of science, that is, on scientism as an ideological stance. Sceptics, of course, use the term scientism as a pejorative; it is meant to call attention to its almost religious faith in science’s supposed omnipotence. But when string theorists insist on their own endo-epistemology, they are, in effect, monopolising authority to philosophize about string theory. How does the promulgation and consumption of an imaginary reinforce the solidity and stability of the ‘edifice’ of string theory? Scientism would seem to obviate the problematic of interdisciplinarity—that specialization typifies scientific practice. In effect, the left hand of science does not know what the right hand is up to. An expert in one discipline has no more authority to assess the verity of another discipline than a lay person. Science is, in this sense, fractured—neither microbiologists, neurochemists, solid state physicists, nor loop quantum gravitists are technically qualified to pass judgment on the value of a given piece of string theory. Often, a string theorist who specializes in its applications to black hole cosmology may not be able to speak with any definitive authority on the subtleties of string field theory. Ultimately, in order to form judgments, specialists in one field only have access—assuming they refuse to sacrifice the years required to hone their knowledge in that other field—to expository accounts of other fields, and thus, to an imaginary. String theory, itself multiple and fractured, finds its place in a veritable Babel Tower of scientific discourses where cross-fertilization and cohesion occur solely by means of imaginaries. Can exposition be objective in the way that string theorists claim mathematics is when it is both logically consistent and confirms experimental data? Or in other words, is it possible to communicate through expository prose in a way that would be conceptually pure, that is, free from contamination by an imaginary? This is an important question insomuch as a negative answer would seem to reinforce the notion that as soon as one departs from mathematics, one is immediately confronted with the mimetic aspects of prose.[62] Exposition may exhibit logical consistency, but string theorists would argue that it lacks the precision necessary for rigorous descriptions on subatomic scales. A major mechanism in expository prose—that which contributes substantially to the production of meaning—even in highly abstract contexts, is that abstraction inevitably employs, to some varying degree and intensity, the concrete, that is, the embodied world of everyday objects, events, and relations. Cognitive linguists George Lakoff and Michael Johnson have stressed the centrality of the image to language. In Philosophy in the Flesh, they make the following points: one, ‘words can designate portions of conventional mental images’; two, ‘mental images do not vary widely from person to person [and] conventional mental images are shared across a large proportion of the speakers of a language’; three, a ‘significant part of a cultural knowledge takes the form of conventional images and knowledge about those images’; and four, the ‘meaning of the whole is not a simple function of the meanings of the parts’. They emphasize that, between these images, the ‘relationship is complex’; it consists of the ‘linguistic expression of the image plus knowledge about the image plus one or more [inferential] mappings’.[63] Cognitive linguists argue that an imaginary is fundamental to expository prose as linguistic expression. The language of formal logic might serve as an exception, in that images are generally stripped away and replaced with ‘pure’ symbols. Formal logic thus privileges the relationships among the symbols, rather than any correspondence between symbols and embodied human experience. In The Rule of Metaphor, Paul Ricoeur argues that it is indeed possible to isolate the conceptual content of prose from its imaginative content. He writes:
What Ricoeur describes here—expression where ‘concept becomes capable of functioning semantically in terms of the configurational properties of the space in which it is inscribed’—is epitomized by the language of formal logic. To reiterate, such language privileges internal relationships within the system over the ‘double meaning’ of images. Ricouer, in a stance reminiscent of the logical positivists, argues that while concept in exposition can liberate itself from an imaginary, imaginaries are still useful. Imaginaries, he writes, ‘are not things at all; rather, they introduce a new language, like a dialect or idiom, in which the original is described without being constructed’; an ‘imaginary medium is […] nothing more than a mnemonic device for grasping mathematical relationships’. This echoes the positivist sorting of the context of discovery from the context of justification. An imaginary serves merely a didactic function. Ricouer continues: ‘The important thing is not that one has something to view mentally, but that one can operate on an object that on the one hand is better known and in this sense more familiar, and on the other hand is full of implications and in this sense rich at the level of hypotheses.’[65] Here Ricouer acknowledges the utility of a imaginary, that it draws upon images from everyday experience, which are thus ‘better known’ and ‘more familiar’. But again, the imaginary’s utility lies in its capacity to generate ‘implications’ and ‘hypotheses’, in short, as a form of play. As Le Doueff (and Serres) pointed out, a positivist ideology associates the conceptual with work and the imaginary with school and play. A reader is meant to only take seriously the conceptual—whatever imagery lies latent in the abstractions that arise from conceptual work, one is simply expected to ignore or dismiss out of hand. Le Doeuff describes this implicit agreement in conceptualizing discourse, whether philosophical or scientific, as a ‘dogmatisation’: Images are the means by which every philosopher can engage in straightforward dogmatization, and decree a ‘that’s the way it is’ without fear of counter-argument, since it is understood that a good reader will by-pass such ‘illustrations’—a conviction which enables the image to do its work all the more effectively.[66] As I have argued, the work of an imaginary is to ground concept in familiar human-scale experience, to mediate social agency with the agency of the objects a theory manifests, to invest those objects with substance, and importantly, to situate the theory within a larger interdisciplinary imaginative context. Without this connecting tissue, so to speak, string theory’s mathematical formalism would have no cultural footing. [45] ‘The Universe, which stands continually open to our gaze, cannot be understood unless one first learns to comprehend the language and read the letters in which it is composed. It is written in the language of mathematics.’ From Galileo Galilei, ‘The Assayer’, in Discoveries and Opinions of Galileo, trans. by Stillman Drake (New York: Doubleday, 1957), pp. 237-8. This subscription is not merely a caprice; it is important to acknowledge that mathematics has been integral to the vast majority of scientific and technological advances of the last few centuries. [46] In topology, orientifolds and orbifolds are, roughly speaking, similar yet distinct ways of structuring multidimensional manifolds. [47] ‘From [1995] on, the name ‘superstring theory’ becomes something of a misnomer, since those working in this field now feel that they are studying bits of a much larger theory that contains not only strings but higher-dimensional p-branes. Besides M-theory, this theory has also been sometimes called ‘the theory formerly known as strings.’ From Peter Woit, Not Even Wrong: The Failure of String Theory & the Continuing Challenge to Unify the Laws of Physics (London: Jonathan Cape, 2006), p. 156. [48] For a popular account, see Leonard Susskind, The Cosmic Landscape: String Theory and the Illusion of Intelligent Design (New York: Little, Brown, 2005). [49] See Traweek, Beamtimes and Lifetimes, p. 74. [50] ‘To really understand superstring theory, one should first study quantum field theory, and in itself this is a very demanding task. Typically, graduate students take a course in quantum field theory during their second year of graduate school, in which case they can’t even begin work on superstring theory until their third year. This leaves little time to master the subject and get some new results about it in the standard four- to five-year length of the PhD program. Young superstring theorists often gain their degrees having only become really familiar with a small part of the subject, with true expertise requiring many, many years to achieve.’ From Woit, Not Even Wrong, p. 200. [51] One version of this is called Anti-de-Sitter Space/Conformal Field Theory or AdS/CFT. See, for example, Penrose, Road to Reality, pp. 920-22, and Woit, Not Even Wrong, pp. 156-7. [52] Traweek, Beamtimes and Lifetimes, p. 111. [53] From Randall, Warped Passages, p. 8. [54] Martina Merz and Karin Knorr Cetina, ‘Deconstruction in a “Thinking” Science: Theoretical Physicists at Work’, Social Studies of Science, 27:1 (1997), 73-111, p. 74. [55] For example: ‘Einstein’s equations of general relativity are elegant and geometrical. They embody the conceptual foundation of the theory and feel completely up to the task of describing gravitation. No similar equations are known for string theory.’ From Barton Zwiebach, A First Course in String Theory (Cambridge: Cambridge U. Press, 2004), pp. 10-1. And: ‘But most researchers feel that our current formulation of string theory still lacks the kind of core principle we find at the heart of other major advances. Special relativity has the constancy of the speed of light. General relativity has the equivalence principle. Quantum mechanics has the uncertainty principle. String theorists continue to grope for an analogous principle that would capture the theory’s essence as completely.’ From Brian Greene, The Fabric of the Cosmos: Space, Time, and the Texture of Reality (New York: Random House, 2004), p. 376. [56] For string theorists, a statement such as ‘the world is made of strings’ or ‘all quantum particles are variations on a fundamental string’ does not qualify as a principle, although their rationale for this is somewhat obscure. [57] One example of an image from the general relativity imaginary is the bending and warping of the spacetime fabric. [58] Michael Shermer, ‘The Shamans of Scientism’, Scientific American, June 2002. [59] Consider how many times one hears in popular discourse the following phrase: ‘Science has made a breakthrough…they’ve…’, a multitude speaking with one voice from the same perspective. [60] Bachelard, New Scientific Spirit, p. 14. Serres also takes this position: ‘Reason makes use of concepts, under whose unities are sheltered multiplicities that are most often highly dispersed.’ From Michel Serres, Genesis, trans. by Genevieve James and James Nielson (East Lansing, MI: U. of Michigan Press, 1997), p. 3. [61] Paul Feyerabend, Against Method (London: Verso, 1993), p. 14, 245. Needless to say, Feyerabend takes a dim view of scientism for non-scientists: ‘The lesson I draw from this sequence of events is that a uniform “scientific view of the world” may be useful for people doing science—it gives them motivation without tying them down. It is like a flag. Through presenting a single pattern it makes people do many different things. However, it is a disaster for outsiders (philosophers, fly-by-night mystics, prophets of the New Age). It suggests to them the most narrowminded religious commitment and encourages a similar narrowmindedness on their part.’ Against Method, p. 250. [62] I am sceptical that an analysis of the mathematics itself would exonerate it too from the collusion with imaginaries—but such an examination is beyond the scope of this thesis. For those interested, see George Lakoff and Rafael Núñez, Where Mathematics Comes From: How the Embodied Mind Brings Mathematics Into Being (New York: Basic Books, 2001). [63] Lakoff and Johnson, Philosophy in the Flesh, p. 69. [64] Paul Ricouer, The Rule of Metaphor: Multi-disciplinary Studies of the Creation of Meaning in Language, trans. by Robert Czerny (Toronto: U. of Toronto Press, 1977), p. 302. [65] Ricouer, Rule of Metaphor, p. 241. [66] Le Doeuff, Philosophical Imaginary, p. 12. |
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