Mad reveries find notoriety in limbo

For the rational person, one of the universe's great puzzles is just how often the lunatic reveries of theoretical scientists end up being proved by experiment. It is a reverse "grasshopper and ant'' tale that may be called "prediscovery'' if we follow the coinage of Strange Matters' author Tom Siegfried.

A prediscovery works roughly like this: someone (say Albert Einstein) indulges in a flight of creative accountancy to find the logical implications of known physical facts when combined with imaginary ones. He thus "prediscovers'', for example, that time must dilate for moving observers - that they should age more slowly. Of course, he is not sure of his prediction (which at this stage is merely a prospective prediscovery), but he does believe that mathematical consistency should lead to the proposed new fact. Years later, time dilation is actually observed. Indeed, it becomes so much an experimentally proved fact that it makes its way into the toolbox used by engineers to produce new technology. How did the prediscovery happen? It just isn't fair.

Strange Matters is about the world of prediscoveries past and, more to the point, present. It describes the full weirdness of scientific speculations that are too recent to have been proved or disproved. The timing makes a difference; it is what renders the new ideas "strange matters''. If these ideas are disproved, they will stop being odd and become simply wrong. If they are proved right, they lose their outlandish nature as people get used to them as a fact of life. But while they dwell in the grey area, scientific speculations do look like the product of deranged minds: heterotic superstrings and multidimensional branes, multiverses with non-trivial topologies, doughnut universes and bidimensional time. Not surprisingly, lawyers involved in scientific copyright cases sometimes find it hard to distinguish the works of modern physicists from junk produced by cranks.

Given the wealth of the subject, Siegfried's book is a disappointingly random assortment of what goes on at the cutting edge of cosmology, particle physics and quantum gravity, rather than a proper safari through the jungle. But it does have some unquestionable merits, especially in its treatment of the background material. It ventures into quite unusual territory for a popular science book. For instance, it describes in some detail Emmy Noether's remarkable explanation of the law of conservation of energy, and the modern view that conservation laws are nothing but an expression of symmetry.

It also presents some very original angles into well-trodden science history. I loved Siegfried's explanation of why the Russian scientist Alexander Friedmann managed to beat Einstein to the prediscovery of the big bang. Apparently, Friedmann was rather fond of Edgar Allan Poe - who had poetically proposed the expanding universe years before the scientific counterpart was found.

But where the book tries to take a stance - in its depiction of the drama of new science in the making - it is truly lame. The trouble is that Siegfried seems to be infatuated with the folklore floating around the scientific community, and he gives it precedence over the concepts. Usually popular science denudes complex theories of their technicalities to present the "handwaving'', qualitative core. This is achieved by means of simple words and analogies, avoiding mathematics and jargon like the plague. By way of contrast, Siegfried is obsessed with the nerdy jargon of modern science (Wimpzillas, squarks, Qballs and so on) and the book in places seems to be nothing but a parade of these fancy words. If the jargonorrhoea does not obscure the argument it is only because quite often there is none (the chapter on superstrings and membranes is particularly lightweight).

Add to that a stream of extremely weak puns, and what begins as a mildly disappointing book soon becomes truly infuriating. Ironically, the book works only when dealing with the past.

I could forgive the lack of content and scientific inaccuracies, but it is inexcusable that Siegfried - a journalist - in places entirely misses the sociological plot. At one point he staunchly defends string theory (the view that the fundamental constituents of matter are vibrating strings instead of particles), comparing its current critics to the 19th-century physicists who were sceptical of atoms. In those days eminent scientists, of the calibre of Ernst Mach, accused atoms of not being properly scientific (indeed they regarded them as "metaphysical''), arguing that atoms could not be seen. But, as Siegfried observes, today atoms have actually been "seen'' - by means of suitable microscopes - so any doubts over their physical nature have evaporated. And one day, he concludes, we may see strings too... So there!

He fails to note that, at the end of the 19th century, atomic theory had explained a phenomenal body of observations in chemistry and thermal physics. Atoms had not been observed, but as a simple hypothesis capable of explaining everything that was experimentally known in physics and chemistry, they were remarkably successful. In sharp contrast, string theory has not explained or even predicted a single feature about the real world. It is a mathematical indulgence that has failed to connect with the universe we live in at the most basic level.

This is, I believe, the substance of current critiques of string theory; not the argument he obviously got from one of his interviews with scientists. And the problem is that Siegfried's idealised "string critic'', carefully contrived to lack strength and allow his favoured boxer to shine, is typical of the mistake he makes too often in his book. It only drives home a sad fact: how some science writers happily swallow any hype unscrupulous physicists throw at them.

João Magueijo is reader in theoretical physics, Imperial College London.