books and arts Einstein not yet displaced Controversial theory of varying speed of light still lacks a solid foundation. Faster Than the Speed of Light: The Story of a Scientific Speculation MILES COLE by João Magueijo William Heinemann/Perseus: 2003. 320 pp. £16.99/$26 George Ellis João Magueijo is one of many who hope to see the epitaph ‘Einstein was wrong, I was right’ on their gravestone. He is a cosmolo- gist who, one rainy morning in Cambridge, suddenly saw the possibility of a varying speed of light (VSL) as an alternative to the inflationary-theory paradigm that domi- nates present-day theoretical cosmology. He knew from the start that it represented a fundamental challenge to physics ortho- doxy (it violates the foundations of Einstein’s special theory of relativity) and would not easily be accepted, but he worked enthusi- astically to develop the idea. He found a collaborator who wavered but eventually completed a joint paper with him on the topic. This was rejected by major journals but was eventually accepted for publication read and referred to. Why, then, his major dis- Magueijo has not gone back to the founda- after a long battle. He then discovered that content? He has had no more difficulty than tions and sorted them out. Any theory of the idea had already been proposed, in a many others who have presented challenges this kind needs, first, a viable proposal slightly different form, by John Moffat. He to orthodoxy. All major new ideas have for measuring both time and distance, as found new collaborators and with them been resisted in their time: the expanding velocity is based on this; second, a physical developed variants of his theory. Universe, continental drift, special relativity model that embodies the results of these Faster Than the Speed of Light is a lively and quantum theory, for example. Science measurements in some well-defined mathe- book that captures the excitement and is inherently conservative — it has to be matical structure; and third, a theory of frustrations of doing real-world science. so, given the flood of speculative writing. It electromagnetism that predicts the speed Magueijo relates interestingly how his VSL also has to be open, allowing dissemination of light in relation to these measurement proposal might possibly be a way out of some of unorthodox views, which does occur. It is processes. He has none of these, and without major puzzles facing cosmology, which he resistive but not impermeable, as is shown them he does not have the basis to put his explains well. There are irritating passages, in his own case. There is a valid complaint, theory on a solid foundation. however, where he makes extended use of a nevertheless: the current use of refereeing as Standard relativity theory deals with all metaphor involving farmers and cows in a defence of the inflationary-theory ortho- these issues in depth. The key point is that explaining relativity theory. Magueijo states doxy in cosmology is indeed regrettable. current ways of measuring distance precisely that this is based on a dream that Einstein Magueijo’s dissatisfaction is wider than incorporate the speed of light in their had as a boy — a fictional invention that that, however. He criticizes all university foundations. On large scales, radar (with displays such a cavalier attitude to historical administration as parasitic and unnecessary, its variants such as the Global Positioning truth as to call into question his other throwing in gratuitous insults as he does System) is the only viable method. It is then historical claims (and for the record, it was so. He is breathtakingly arrogant as regards not possible for the speed of light to vary, Richard Tolman, not Yakov Zeldovich, who funding — he seems to assume it is his right because it is the very basis of measuring first investigated the thermodynamics of to be funded for the work he is doing with distance; as emphasized by J. L. Synge, the bouncing universes). And at times Magueijo no questions asked. He gives no attention to natural units for distance are light seconds descends to an altogether different space the methods by which one can decide how or light years, rather than metres or miles. characterized by hostile ranting (“seem to public funding should be dispensed in sci- Furthermore, this is then built into the fancy themselves as scientific pimps”) and ence, nor to why the public should pay any foundations of the theory through the space- crude language. In these passages he express- money at all to people like him. Yes, there time metric tensor and its interpretation as es his profound dissatisfaction with how he are problems in university organization and determining proper time (time measured by has been treated by the scientific world the funding system; constructive criticism an ideal clock along its worldline), proper despite the recognition and generous sup- is justifiable and indeed needed. But his distance (measured by radar), and the null port he has received (he was awarded a remarks are purely destructive. cone (characterizing the path of light through Cambridge fellowship and a Royal Society What of the VSL theory itself? Is it the space-time). Because Magueijo and Moffat research fellowship, and is a reader at Imperial panacea he hopes for? No, it is not. Einstein ignore this physical interpretation of the College, London). reflected deeply on the foundations of metric, their so-called ‘phase transition in His papers on VSL have now been widely physics, and that was the basis of his success. the speed of light’ is just a jump in arbitrary NATURE | VOL 422 | 10 APRIL 2003 | www.nature.com/nature © 2003 Nature Publishing Group 563 books and arts units for time, unrelated to measurement procedures. It is not a physical prediction. Furthermore, the variation principles proposed as underlying the physics involve the metric tensor in raising and lowering indices to create scalars — and hence build into the foundations of the theory the invari- ance of the speed of light (the metric deter- mines the speed of wave propagation). We are given no reason why any broken symmetries associated with special solutions of the result- ing equations will give a causal explanation DE LA MARINE ARCHIVE/MUSÉE ART ORTI/THE D. for a varying speed of light — but this variation is the arbitrary postulate of VSL theory. And apart from the part of the action determining variation of the speed of light (independently of Maxwell’s equations), the explicit occurrence of the speed of light in the VSL variational principle proposed is only in a ratio with the gravitational constant G— so this is just a varying-Gtheory in disguise. Developments that could make VSL viable, such as further investigation of the More than the sum of its parts: the relationship between the planks determines what kind of boat it is. time variation of the fine-structure constant, of two-metric theories, of an altered version of life. The first problem faced by the author, of the symmetry group underlying relativity Antoine Danchin of the Pasteur Institute theory, or through a string-theory motiva- C’est la vie? in Paris, France, is how best to describe a tion for varying ‘constants’, need to provide The Delphic Boat: What Genomes genome. He borrows from Greek mythology a clear relation to space and time measure- Tell Us the tale of the oracle of Delphi, which asked ment, as well as a physical reason (based in by Antoine Danchin, transl. Alison Quayle whether a boat that has had all of its planks some version of Maxwell’s equations) for the Harvard University Press: 2003. 368 pp. $35, replaced over time is still the original boat or speed of light to vary. It is a pity that Magueijo £23.50, E35 not (to its owner, who watched its evolution, does not mention progress made in these Axel Meyer it would be). Danchin makes the point that it directions by workers other than himself and is the relationship of the planks (or in the his own collaborators. I This contribution from old Europe’s grande case of the genome, the genes) to each other George Ellis is in the Department of Mathematics, nation discusses genomics, the politics of that determines what kind of boat (genome) University of Cape Town, Rondebosch 7700, genome research, the philosophy of science, it is; individual planks are less important in Cape Town, South Africa. and the not-so-small question of the nature determining the essence of a boat. It has been known for some time that a genome is not merely a set of independent Preying for dinner-time genes arranged like pearls on a string. The essence of a genome has been described Mantids are ambush predators as a code, a blueprint, a musical score and that keep still and wait for a set of instructions. All of these metaphors other insects to approach are used in an attempt to convey the notion before striking and feeding on that a genome is more than the sum of them. Like other mantids, the its parts. female mantis Harpagomantis From an evolutionary biologist’s point discolor shown here is of view, each organism’s genome (including camouflaged and remains our own) is a record of its evolutionary motionless, or rocks slightly history: genomes are shaped by symbioses from side to side to side as if and hybridizations, as well as by natural swaying in the breeze, all the selection. In attempting to understand the while keeping its forelegs origin and diversification of life, the increase folded in a manner in complexity during ontogenetic develop- reminiscent of prayer.