Weird Notions That Drive Science
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book reviews (could Edgar Allan Poe really have inspired superstrings? Strange-quark matter? Large the physicist Alexander Friedmann to ponder extra dimensions? Elementary-particle dark Weird notions that an expanding Universe?), all serve to illus- matter? Siegfried explains each of these trate the intriguing power of mathematics in questions, usually with clarity and integrity. drive science describing the physical Universe. The end Physicists will be gratified by his testimonial Strange Matters: Undiscovered result is not just a tour of current theoretical in support of the Big Bang, and impressed Ideas at the Frontiers of Space speculation on time, space and matter, but that he managed to work in an accurate and Time rather a cogent argument as to why we should description, accessible to the layman, of by Tom Siegfried take these exotic ideas seriously. the branch of mathematics known as Joseph Henry Press: 2002. 224 pp. $24.95 The consistent success of mathematical group theory. Marc Kamionkowski equations in describing physical phenomena The choice of topics is rather unusual, has surprised and enticed scientists and beginning with a search for strange-quark For almost 30 years, physicists have been philosophers for years. Siegfried’s point is matter (something a bit off the beaten path facing a long haul across the almost inter- that mathematical physics is not just numer- of physics today) and then moving on to minable desert to the grand unified theory ology or catalogues. There is something supersymmetry, string theory and large (GUT) of strong, weak and electromagnetic deeper, as can be seen in the numerous cases extra dimensions, which are central currents forces. This theory postulates an almost where scientists have been able to get more of modern particle theory. But this eclectic unimaginably huge gap between the energies out of the equations than they put in. Paul mix helps to set the book apart from other of current particle accelerators and those Dirac’s equations to describe the relativistic recent popular books on similar subjects. at which the manifestations of unification quantum behaviour of electrons required Although the prose is at times a bit dry, become most apparent. If that’s not suffi- the existence of positrons — positively the pace is just right and the presentation ciently daunting, string theorists have charged particles subsequently discovered by engaging. Except for a few notable cases speculated further, suggesting that gravity Carl Anderson. Friedmann’s ‘prediscovery’ (such as a proposal that extrasolar planets is tied to the other three interactions at an of the Universe’s expansion presaged its are made of mirror matter), the discrepancy even higher energy scale. observational discovery by Edwin Hubble. between the well established, plausible, However, in the past few years some theor- Wolfgang Pauli’s neutrino, which was first unlikely and far-fetched is discerned clearly. ists have begun to question whether this required to satisfy energy conservation, was There is also some subtle humour. For desert is real. String theory has long postu- then found in particle beams. example, at the end of the book Siegfried lated the existence of additional spatial Today an assortment of curious phenom- discusses duality — roughly dimensions, beyond the three that we know, ena arise in the mathematics of theoretical speaking, this is the but these have always been thought to be physics. Which, if any, of these will be notion that several microscopic. It has recently been suggested confirmed in the laboratory? Will it be theories that seem that some of these dimensions may be as large as a millimetre. To see how a dimension High noon at can have size, imagine tightly rolling a sheet of paper; the resulting ‘curled’ dimension the meridian will be much smaller than the original dimension. If these dimensions are a milli- Among the 5,000 scientific instruments metre in size, the extraordinary and mysteri- at the National Maritime Museum ous weakness of gravity relative to the other at Greenwich in London, UK, three forces could be due to its leakage into is a remarkable collection of other dimensions. If that’s right, unification sundials and related instruments, could be just around the corner. Instead of ranging in origin from the Far East trekking across a vast featureless energy and Islamic countries to London itself. expanse, we may well see radical departures It includes dipleidoscopes, like the one shown here, from physics as we know it in laboratory which were used to provide an accurate time check at experiments any day now. These will tell us noon, when the Sun passed over the meridian of the whether or not the large extra dimensions observer. The collection is catalogued in extraordinary are just a theoretical mirage. detail in Sundials at Greenwich: A Catalogue of the Both the GUT desert and these large extra Sundials, Horary Quadrants and Nocturnals dimensions are motivated, at least in part, in the National Maritime by elegant mathematics. This ‘prediscovery’ Museum, Greenwich of physical phenomena — their discovery (Oxford University in mathematical equations that anticipates Press, £99.50), edited their discovery in the laboratory — is the by Hester Higton. The unifying thread of Tom Siegfried’s enjoyable book also includes new book, Strange Matters. Although the chapters that set eponymous matter here is most literally the instruments strange-quark matter, which is discussed in in a cultural the opening chapter, other ideas, such as and mirror matter, large extra dimensions, historical supersymmetry, dark matter, unification, context. string theory and even extra time dimen- sions are, by any reasonable standard, also pretty strange. These subjects, as well as a variety of interspersed curious historical vignettes 362 © 2002 Nature Publishing Group NATURE | VOL 420 | 28 NOVEMBER 2002 | www.nature.com/nature book reviews to describe different physical situations can question: “What are you doing with your actually be mathematical equivalents. This knowledge once you get it?” This, of course, concept comes in handy when he tries to presupposes the neutrality of science, which reconcile the apparent inconsistency in the Beckwith denies. thesis of this book — that great ideas drive Beckwith’s activism was also an outcome progress in science — to that in his previous of his preoccupation with history. He real- PRESS UNIV. HARVARD book, The Bit and the Pendulum (John Wiley, ized that, in contrast to physicists, who had 2000), which postulates that technological openly confronted their historical burden of advances drive scientific discovery. Although the past, the atomic bomb, geneticists were duality is not meant to imply that you ignorant of their own ‘atomic’ history — can always have it both ways, in this case their role in the eugenics movement. Suspi- maybe he can. ■ cious of genetic research that claimed to Marc Kamionkowski is in the Division of Physics, explain antisocial behaviour, he launched a Mathematics and Astronomy, California Institute campaign against a study at Harvard Medical of Technology, Pasadena, California 91125, USA. School on the development of boys with an extra Y chromosome (XYY). Beckwith was concerned about the ethics of identifying and studying these children, because many people still believed previous, seriously A social activist flawed scientific claims that linked this chromosomal aberration with criminal in genetics behaviour. The Harvard researchers finally Making Genes, Making Waves: decided to stop the screening. However, this A Social Activist in Science campaign, because of the distrust it caused by Jon Beckwith Social conscience: Jon Beckwith was the first to between the activists and faculty members, Harvard University Press: 2002. 256 pp. isolate a gene, but warned of the risks of genetics. affected Beckwith’s life more than any other. $27.95, £18.50, 27.95 euros E. O. Wilson’s book Sociobiology: The Ute Deichmann flashes of intuition, even the passions that New Synthesis (Harvard University Press, drive us in science”. 1975) presented a new theory about genetic “Science was puzzle-solving — figuring out Beckwith’s growing enchantment with programmes of behaviour in animals and mathematical proofs or devising pathways science was mirrored by his growing concern humans. It received wide media coverage. for the synthesis of complex organic com- for its consequences. His social activism in In their public attack on the theory, in which pounds — it was fun.” The joys of doing science grew out of a more general political they said it was biologically determinist, science, first experienced in college, motivated radicalism in the 1950s and 1960s, stimu- Beckwith and his colleagues went as far as Jon Beckwith to become a scientist — and to lated especially by the civil-rights movement to associate Wilson and his theory with remain one. He is now professor of micro- in the United States, the assassination of Nazism. Whether the scientific evidence biology and molecular genetics at Harvard Martin Luther King, and the turmoil over that Wilson presented was strong or weak, Medical School. But literature, philosophy the Vietnam War. As a member of the action some of the attacks were blatantly unfair. and social concerns have remained impor- group Science for the People, he was con- Social activists in science have to show tant to him throughout his scientific life. In vinced that scientists have a special social responsibility, too. 1969, Beckwith was the first to isolate a single responsibility, so he decided to help inform In 1989 Beckwith joined the programme gene from a chromosome (of the bacterium the public about the potential negative social to explore and anticipate the ethical, legal Escherichia coli) and, two decades later, his consequences of genetic research. In 1969, and social implications of the Human experiments on protein secretion from cells in the same week that his famous paper Genome Project. The resulting public dis- opened up new lines of research on the about the first isolation of a gene appeared cussion of this issue led to the passage of process of protein folding.