The Universe Within: From Quantum to Cosmos. By Neil Turok. House of Anansi Press; 292 pages; C$19.95. Faber and Faber; £17.99. Buy from Amazon.com, Amazon.co.uk

Farewell to Reality: How Modern Physics Has Betrayed the Search for Scientific Truth. By Jim Baggott. Pegasus; 352 pages; $26.95. Constable; £12.99. Buy from Amazon.com, Amazon.co.uk

Time Reborn: From the Crisis of Physics to the Future of the Universe. By Lee Smolin. Houghton Mifflin Harcourt; 319 pages; $28. Allen Lane; £20. Buy from Amazon.com, Amazon.co.uk

PHYSICISTS have a lot to crow about. Last year they finally found the Higgs boson, which some call “the God particle”. The discovery completes the Standard Model, a 40-year-old blueprint for how nature behaves at the smallest end of the scale. In April the European Space Agency’s Planck satellite presented the most detailed picture yet of the cosmic microwave background (CMB), a relic of the radiation produced 400,000 years after the big bang, which holds clues to the universe’s birth pangs 13.8 billion years ago.

For all its successes, though, modern physics leaves some crucial questions unanswered. Chief among these is how to reconcile the two great discoveries of the 20th century—the Standard Model and Albert Einstein’s theory of general relativity, which deals with gravity—into “a theory of everything”. Many scientists are asking themselves, what next?

Neil Turok, who heads Ontario’s Perimeter Institute (PI), one of the world’s leading centres for theoretical physics, thinks that answers are coming. His latest book, “The Universe Within”, based on the Massey Lectures he gave in Canada last year, is now being published in Britain. It is a paean to the power of physics, or what he calls “magic that works”. Mr Turok offers a selective overview of the latest thinking. This includes the author’s own pioneering contributions to cosmology, in which the big bang is viewed not as an isolated incident but as a recurring event in an endless cycle of expansion and collapse.

Mr Turok’s theory, sometimes referred to as the “big bounce”, avoids the problem faced by many other proposals, which assume that the universe sprang to life in a “singularity”, a point of infinite density. The big-bounce hypothesis bypasses this by assuming that a collapsing universe begins reflating before becoming infinitely dense. No theory yet devised is capable of dealing sensibly with such extreme conditions, where particle physics melds with gravity. Nor is it possible to explain how the observable universe emerged from them, but Mr Turok is working on this.

So far, his idea remains speculative, though less so than many rival proposals. Unlike those, it makes predictions which can be tested experimentally, not now but perhaps in the near future—for instance through detailed analysis of the CMB. He is sparing with technical explanations. This helps the narrative tick along, though occasionally at the expense of clarity, as when he discusses Einstein’s formula, E=mc2.

A white South African who fled the country with his parents during the apartheid years, Mr Turok grew up in Britain. He believes that science has much to gain from tapping the vast pool of talent in Africa. One advantage of being in effect secluded from the prevailing scientific mindset, he believes, is that Africans might have fresh insights to offer. To aid the search for an African Einstein, Mr Turok created the African Institute for Mathematical Sciences in Cape Town in 2003. It now has offshoots in Ghana and Senegal, with another planned for Cameroon.

Jim Baggott is not so confident that progress in physics is assured. In “Farewell to Reality” the former physicist—who left academia but still occasionally writes about science—bridles at the ubiquity of what he calls “fairytale physics”: the flights of mathematical fancy, based on nothing more than personal taste, that he feels have come to litter the theoretical landscape over the past two decades.

Following mathematical hunches can, of course, pay off. A good example is the Higgs, which emerged from an equation in 1964 and was then discovered 48 years later. The first, indirect inkling that the Higgs might be real came as early as 1973. By contrast, string theory, a popular class of mathematical models which describe all the elementary particles and forces of nature as different configurations of tiny vibrating strings, has been explored by thousands of bright scientists since the 1970s. But it has yielded little in the way of testable predictions, let alone actual evidence.

Such tilting at windmills fills Mr Baggott with scorn. Yet his fierce and refreshing polemic does a fine job of helping readers understand some of the knottiest ideas in contemporary physics. This is all the more remarkable as he eschews analogies, arguing that they tend to confuse rather than illuminate the counterintuitive ideas and phenomena he describes.

Even Mr Baggott would agree, though, that some high theorists are careful to ensure that their work rests on more than just layers of dubious if mathematically pleasing assumptions, and that it is, at least in principle, subject to experiment. One such is Lee Smolin, Mr Turok’s colleague at PI, who is considered one of the most original living theorists. Mr Smolin believes that the impasse highlighted by Mr Baggott is the result of applying theories that work for small, isolated systems to describe the universe as a whole. In “Time Reborn” he argues that the way out of the funk caused by doing “physics in a box” is to embrace time as a fundamental feature of reality.

This does not sound like a radical idea; time, after all, is central to all human experience. Yet Mr Smolin makes a compelling case that the mathematical models which have dominated physics since the days of Isaac Newton have replaced processes unfolding in time with “timeless laws”. Einstein dealt perhaps the biggest blow to what Mr Smolin calls “real” time by treating it both as a static dimension akin to length, width and depth, and as a concept in which the boundary separating the past from the future is different for different observers. He even consoled a friend’s widow by saying that “people like us, who believe in physics, know that the distinction between the past, present and future is only a stubbornly persistent illusion.”

For time to be “real”, in Mr Smolin’s sense, it cannot be relative. But nor can it be absolute in the Newtonian mould, where the future already exists, by dint of inexorable logic. This leads Mr Smolin to some audacious ideas. He challenges not only Einstein’s relativity, but also the very notion of natural laws as immutable truths. He also questions the usefulness of mathematics in modelling the universe in its entirety. Models shed light on processes which recur; the universe, by definition, happens just once.

Mr Smolin believes that a hypothesis does not need to be framed in equations to be scientific. All it has to do is to suggest observations by which it can be confirmed or refuted. He cites evolution by natural selection as a prime example, and one that physicists ought to emulate. Indeed, Mr Smolin’s own theories have grown a bit less mathematical over the years. Can such a switch lead to a deeper understanding of nature? As the author himself says: “Only time will tell.”