It comprises three parts divided into a total of 12 chapters, the three parts are headed:

1)      The Nature of Reality;

2)      The Nature of the Universe; and

3)      Life and the Universe.

I am not sure that this sub-division achieves very much more than the chapter headings alone.

Chown’s purpose is to widen our imagination by showing us some fairly recent speculative hypothesising by various eminent theoretical physicists. Some of these conjectures are more grounded than others but the basic pattern is the same: state some facts; ask some questions; express complete puzzlement; come to the rescue with suggested meanings from a scientist or two; scatter around words such as, ‘Astonishing’ ‘Amazing’ ‘Remarkable’ or even ‘Astounding;’ move on to the next topic.

Some of the chapters deal with fairly well-worn ideas such as ‘Many worlds’ ‘Panspermia’ and ‘the Multi-verse’ but there were others that I had not previously encountered including the possibility of the arrow of time running backwards, mirror particles (not to be confused with anti-matter) and interstellar dust comprising bacteria (a variation of panspermia).

The last example emerges from the puzzle that stars should be brighter than they appear but they have been dimmed, apparently, by clouds of dust each particle of which has been calculated to be the precise size of a single bacterium. From this the late Fred Hoyle and Chandra Wickramasinghe (two eminent cosmologists) speculate that passing comets pick up some of these possible bacteria and release them as the comet nears the sun. The solar wind then scatters them to all corners of the universe and some, inevitably, will fall on to planets. We know how hardy bacteria can be, surviving extremes of heat and cold, just waiting for favourable conditions before bursting into life and dividing. This is how life might have arrived on earth in its formative stages just waiting for it to cool sufficiently for liquid water to provide ideal living conditions. If true, life is probably common in the cosmos but intelligent life rare as it would not have had sufficient time to develop much beyond where we are now. The evidence is interesting without being compelling. The trouble with this conjecture is: where did the cosmic bacteria come from in the first place? Hoyle and Wickramasinghe are silent.

‘Many worlds’ is based on the peculiarities of the wave function in quantum mechanics. It states, briefly, that all possible realities exist as parallel worlds but we can only experience the one that we are in. The ‘Multiverse’ is a logical extension of string theory whereby there are an infinite number of universes created from the vacuum, each with its own unique set of physical laws. It follows that perhaps this is the only one so far created that is suitable for life.

I must say that I rather enjoyed the book. There is more depth I felt than the one I recently reviewed by the same author. In the end though it depends for its impact on the Erich von Daniken approach in the 1970s – ‘We can’t explain x, so it must have been caused by y.’ I suppose much religious faith is based on such speculations – ‘Where did the world come from? No idea, so it must have been created by… (substitute whichever is your chosen creation myth.) Books like this rely for their success on our craving for concrete answers, our apparent need for certainty. The human mind, like nature, abhors a vacuum.

Strictly speaking this book should be entitled, ‘Physics Cannot Hurt You,’ as the second half of it is devoted to what Chown calls ‘Big things.’ The quantum world, of course, deals with very small things. The title gives it away as a light-hearted quick run round the current state of theoretical physics. This sort of jocular science writing for the masses, as it were, has become fashionable of late but I found the humour here laboured and many of the metaphors unoriginal. On the other side of the equation, however, the book undoubtedly works as vehicle for explaining difficult concepts lucidly and simply for us non-physicists. The depth of his scholarship and the love he has for his subject are also evident throughout. I particularly liked his sparing use of footnotes as a way of giving us the real science without spoiling the narrative.

The book is divided into two parts – Part 1: Small Things and Part 2: Big Things (of course) with a vain attempt at the end to reconcile the two. His approach is to amaze us with the sheer improbability of the world we live in and to demonstrate just how counter-intuitive both quantum theory and General Relativity are. The Foreword begins with a bulleted list of unlikely things that, of course, turn out to be true. The first one, for example, states that every breath one takes contains at least one atom that was breathed out by Marilyn Monroe. There is much more of this sort of stuff in the book.

Each chapter is devoted to one physical characteristic beginning with a quote and an italicised introduction. The story begins with the discovery of the atom and what this meant for the then current state of scientific knowledge. He tries to illustrate the properties of the atom with various metaphors. For example, he quotes Tom Stoppard’s famous analogy suggesting that if the nucleus of a Hydrogen atom were the size of a fist then the whole thing would be equivalent to the interior of St Paul’s and its single electron would flutter about the cathedral like a tiny moth.

We are taken on a historical journey as one improbable atomic fact after another is discovered: wave/particle duality; uncertainty; the collapse of the wave function; non-locality; alpha decay; vacuum fluctuation; and how such an apparently diverse world can be constructed from identical building blocks. He admits where he is over-simplifying and lets us know that picturing the true nature of the atom is beyond our imagination.

Part two follows a similar pattern and is substantially devoted to Einstein’s two theories of relativity. The entire book is a mere 158 pp (excluding the glossary) so confining it to the subject of its title would make it a very slender volume indeed. Also, Chown is a cosmologist by profession and this is his bread and butter, so I expect that this part of the book did not take him very long to write. The final chapter deals with some post-Einsteinian discoveries such as Big Bang (the idea had been around for a while but it was only confirmed as a theory in the early 1960s), the existence of Dark Matter and the recent revelation that the universe is not only expanding but also accelerating driven by the mysterious Dark Energy (of which we know almost nothing). The final paragraph expresses the hope that one day (soon?) we will be able to reconcile quantum theory with General Relativity.

I would certainly recommend the book for newcomers to the subject or for those, like me, who are not specialists but would like to keep up with the present state of knowledge (it was first published in 2006). It is an easy read and a lengthy train journey or two should get it finished.

Marcus Chown is a science writer and the cosmology advisor for New Scientist

‘It’s not done to kill the goose that lays the golden eggs, nor to bite the hand that feeds you – nor, in my own profession, to criticise the research programme of the Wellcome Trust, an enormously rich charity that paid much of the bill to read the message written in human DNA. Not done, perhaps, but a pack of renegade biologists has turned on that source of nutrition to claim that what it is doing is welcome, but plain wrong.

Science has done well in studying – and even helping to treat – rare inherited diseases such as haemophilia. After the famous sequencing of the double helix, the hunt started for the genes behind the illnesses that affect most of us – stroke, diabetes, cancer – as well as multiple sclerosis and a variety of brain disorders.

The hope was (and five years ago, it was a reasonable one) that such conditions could be blamed on a small set of common genetic variants. Track them down and we would begin to understand what had gone wrong, diagnose patients before symptoms appeared, and perhaps even come up with a few cures.

The logic was to search the double helix for about half a million variants that could be used to set up a grid of diversity, scattered across the whole genome. This could then be scanned using a magic “chip”, which could identify thousands of changes at once to see whether one, or a few, of the molecular milestones might predispose a given individual to a particular disease. If so, the actual gene responsible could be close to the telltale marker.

The latest version of this grid, produced by what is known as the Wellcome Case Control Consortium, involves 120,000 samples, taken both from invalids and those who are perfectly healthy. It is a huge – and expensive – operation. Just a couple of years ago there was real optimism that a new era of understanding was around the corner. That did not last long, for hubris has been replaced with concern: like Macavity the Mystery Cat, the evidence of genetic inheritance is clear, but the genes themselves are just not there.

Take height. A good way of predicting how big a baby will grow is to measure its mother and father. Tall parents have tall children, and height is highly heritable. The molecular mappers have now used their tape measures on around 30,000 people. They find 50 or so different genes associated with being tall or short – but altogether, they account for only one part in 20 of the variation needed to explain the similarity of children and parents. Macavity has struck, and does so again and again.

To give another example, today’s explosion of obesity means that tomorrow’s greatest killer may be adult-onset diabetes. The genome scans reveal 18 different bits of chromosome that light up as culprits – but together they explain less than one part in 20 of the overall inherited liability to diabetes. At that rate, as many as 800 different genes may be behind this illness; which means that their individual value as predictors of risk is tiny.

In other words, our chances of being born with a predisposition to a common illness such as diabetes or heart disease are not represented by the roll of a single die, but a gamble involving huge numbers of cards. Some people are dealt a poor mix and suffer as a result. Rather than drawing one fatal error, they lose life’s poker game in complicated and unpredictable ways. So many small cards can be shuffled that everyone fails in their own private fashion. Most individual genes say very little about the real risk of illness. As a result, the thousands of people who are paying for tests for susceptibility to particular diseases are wasting their money.

Not all the news is bad, however. Some genes, even those that have a small influence, hint at what may be going wrong in the case of a particular malady. Several of those behind a certain age-related blindness that runs in families are involved in the immune system – an unexpected finding that hints at what its cause might be, and where to start looking for a cure.

Even so, many geneticists now think that the constant pressure to sample thousands and thousands more people for a myriad of unknown genes that have a tiny effect may be misplaced. Instead, we would be better off abandoning the scattergun approach, and reading off the entire three thousand million DNA letters of a much smaller number of individuals, healthy and unhealthy, to see in detail what might have gone wrong.

Whatever the panjandrums of science decide to do with their Everest of cash, it is time to turn to one of the few genetical proverbs, for their mountain has laboured and brought forth not much more than a mouse. And what was that adage about throwing good money after bad?’

Steve Jones is professor of genetics at University College London.

‘”Wonders are there many,” observed the Greek dramatist Sophocles, “but none more wonderful than man.” And rightly so, for we, as far as we can tell, are the sole witnesses of the splendours of the universe – though consistently less impressed by this privileged position than would seem warranted.

The chief reason for that lack of astonishment has always been that the practicalities of our everyday lives are so simple and effortless as to seem unremarkable. We open our eyes on waking to be surrounded by the shapes and colours, sounds and smells of the world in the most exquisite detail. We feel hungry, and by some magical alchemy of which we know nothing, our bodies transform the food and drink before us into our flesh and blood. We open our mouth to speak and the words flow in a ceaseless bubbling brook of thoughts and ideas.

We reproduce, and play no part in the transformation of the fertilised egg into a fully formed embryo with its 4,000 functioning parts. We tend to our children’s needs, but effortlessly they grow to adulthood, replacing along the way virtually every cell in their bodies.

These practicalities are not in the least bit simple, but in reality are the simplest things we know – because they have to be so. If our senses did not accurately capture the world around us, were the growth from childhood not virtually automatic, then “we” would never have happened.

There is, from common experience, nothing more difficult than to make the complex appear simple, just as a concert pianist’s effortless playing is grounded in years of toil and practice – so that semblance of simplicity must reflect the complexities of the processes that underpin them. This should, by rights, be part of general knowledge, a central theme of the school curriculum, promoting that appropriate sense of wonder in young minds at the fact of their very existence.

But one could search a shelf’s worth of biology textbooks in vain for a hint of the extraordinary in their detailed exposition of those complexities of life. Rather, for the past 150 years, scientists have interpreted the world through the prism of supposing there is nothing in principle that cannot be accounted for – where the unknown is merely waiting to be known. At least till very recently, when the findings of two of the most ambitious scientific projects ever conceived have revealed quite unexpectedly – and without anyone really noticing – that we are after all “a wonder” to ourselves.

It started in the early 1980s with a series of technical innovations in genetics and neuroscience that promised to resolve the final obstacles to comprehensive understanding of ourselves. They were, first, the immensely impressive achievement of spelling out the entire sequence of genes strung out along the double helix – the genome – of worms, flies, mice, monkeys and humans, which should have identified those “instructions” that so readily distinguish one form of life from another.

And second, the development of those equally impressive scanning techniques that would permit neuroscientists for the first time to observe the brain “in action”: thinking, imagining, perceiving – all the seemingly effortless features of the human mind.

This was serious science of the best kind, filling learned journals and earning Nobel Prizes while holding out the exhilarating prospect that these most fundamental questions of genetic inheritance and the workings of the human brain might finally be resolved.

The completion of the human genome project, on the cusp of the new millennium, marked “one of the most significant days in history”, as one of its architects described it. “Just as Copernicus changed our understanding of the solar system… so knowledge of the human genome would change how we see ourselves.”

At the same time Professor Steven Pinker, of the Massachusetts Institute of Technology, after reviewing how neuroscientists with their new techniques had investigated everything “from mental imagery to moral sense”, confidently anticipated “cracking the mystery of the brain”.

Nearly a decade has passed since those heady days, and looking back, it is possible to see how the findings of both endeavours have enormously deepened our knowledge of life and the mind – but in a way quite contrary to that anticipated.

The genome projects were predicated on the reasonable assumption that spelling out the full complement of genes would clarify, to a greater or lesser extent, the source of that diversity of form that marks out the major categories of life. It was thus disconcerting to learn that virtually the reverse is the case, with a near equivalence of a (modest) 20,000 genes across the vast spectrum from a millimetre-long worm to ourselves.

It was similarly disconcerting to learn that the human genome is virtually interchangeable with that of our fellow vertebrates, such as the mouse and our primate cousins.

“We cannot see in this why we are so different from chimpanzees,” remarked the director of the chimp genome project. “The obvious differences cannot be explained by genetics alone.” This would seem fair comment but leaves unanswered the question of what does account for those distinctive features of standing upright and our prodigiously large brain.

More unexpected still, the same regulatory genes that cause a fly to be a fly, it emerged, cause humans to be humans with not a hint of why the fly should have six legs, a pair of wings and a brain the size of a full stop, and we should have two arms, two legs and a turbo-sized brain. These “instructions” must be there, of course, but we have moved in the wake of these projects from supposing we knew the principles of the genetic basis of the infinite variety of life, to recognising we have no conception of what they might be.

At the same time, neuroscientists observing the brain in action were increasingly perplexed at how it fragments the sights and sounds of every transient moment into a myriad of separate components, with no compensatory mechanism that would reintegrate them together into that personal experience of being at the centre of a coherent, ever-changing world.

Meanwhile, the greatest conundrum remains – how the monotonous electrical activity of those billions of neurons in the brain “translates” into the limitless range and quality of subjective experiences of our lives, where every moment has its own unique, intangible feel.

The implications are clear enough: while theoretically it might be possible for neuroscientists to know everything about the physical structure of the brain, its “product”, the mind, with its thoughts and ideas, impressions and emotions, would still remain unaccounted for.

“We seem as far from understanding the brain as we were a century ago,” says the editor of Nature, John Maddox. “Nobody understands how decisions are made or how imagination is set free.”

There is in all this the impression that triumphant science has stumbled on something of immense importance – a powerful parallel reality that might conjure the richness of the living world from the bare bones of the genes strung out along the double helix and the parallel richness of the mind from the electrochemistry of the brain.

Certainly, for the foreseeable future there will be no need to defer to those who would appropriate our sense of wonder at the glorious panoply of nature and ourselves, by their claims to understand it. Rather, the very aspect of the living world now seems once again infused with that deep sense of mystery of “How can these things be?”‘

Richard Rorty’s Review

‘Nazi parents found it easy to turn their children into conscientious little monsters. In some countries, young men are raised to believe that they have a moral obligation to kill their unchaste sisters. Gruesome examples like these suggest that morality is a matter of nurture rather than nature — that there are no biological constraints on what human beings can be persuaded to believe about right and wrong. Marc Hauser disagrees. He holds that “we are born with abstract rules or principles, with nurture entering the picture to set the parameters and guide us toward the acquisition of particular moral systems.” Empirical research will enable us to distinguish the principles from the parameters and thus to discover “what limitations exist on the range of possible or impossible moral systems.”

Hauser is professor of psychology, organismic and evolutionary biology, and biological anthropology at Harvard. He believes that “policy wonks and politicians should listen more closely to our intuitions and write policy that effectively takes into account the moral voice of our species.” Biologists, he thinks, are in a position to amplify this voice. For they have discovered evidence of the existence of what Hauser sometimes calls “a moral organ” and sometimes “a moral faculty.” This area of the brain is “a circuit, specialized for recognizing certain problems as morally relevant.” It incorporates “a universal moral grammar, a toolkit for building specific moral systems.” Now that we have learned that such a grammar exists, Hauser says, we can look forward to “a renaissance in our understanding of the moral domain.”

The exuberant triumphalism of the prologue to “Moral Minds” leads the reader to expect that Hauser will lay out criteria for distinguishing parochial moral codes from universal principles, and will offer at least a tentative list of those principles. These expectations are not fulfilled. The vast bulk of “Moral Minds” consists of reports of experimental results, but Hauser does very little to make clear how these results bear on his claim that there is a “moral voice of our species.”

Many of the experiments Hauser tells us about are intended to delimit stages in child development. Three-year-olds already know, for example, that “if an act causes harm, but the intention was good, then the act is judged less severely.” Hauser takes this fact to support the claim that “rather than a learned capacity … our ability to detect cheaters who violate social norms is one of nature’s gifts.” But do such facts as that children learn to use expressions like “didn’t mean to do it” at roughly the same time as they learn “shouldn’t have done it” help us draw a line between nature and nurture? Hauser does not spell out the relevance of data about child development to the question of whether internalizing a moral code requires a dedicated area of the brain.

To convince us that such an organ exists, Hauser would have to start by drawing a bright line separating what he calls “the moral domain” — one that nonhuman species cannot enter — from other domains. But he never does. The closest he comes is saying things like “a central difference between social conventions and moral rules is the seriousness of an infraction.” He takes this to suggest “that moral rules consist of two ingredients: a prescriptive theory or body of knowledge about what one ought to do, and an anchoring set of emotions.” Apparently both rules of etiquette and moral rules embody knowledge about what ought to be done. All that is distinctive about morality is added emotional freight. But, as Hauser tells us, many nonhuman species obey social conventions. (For example, “Do not start tearing at the carcass before the alpha male has eaten his fill.”) It is hard to see why evolution had to carve out a new, specialized organ just to generate the extra emotional intensity that differentiates guilt from chagrin.

Perhaps Hauser does not mean to say that greater seriousness is the only, or the most important, mark of the moral domain. But the reader is left guessing about how he proposes to distinguish morality not just from etiquette, but also from prudential calculation, mindless conformity to peer pressure and various other things. This makes it hard to figure out what exactly his moral module is supposed to do. It also makes it difficult to envisage experiments that would help us decide between his hypothesis and the view that all we need to internalize a moral code is general-purpose learning-from-experience circuitry — the same circuitry that lets us internalize, say, the rules of baseball.

Hauser thinks that Noam Chomsky has shown that in at least one area — learning how to produce grammatical sentences — the latter sort of circuitry will not do the job. We need, Hauser says, a “radical rethinking of our ideas on morality, which is based on the analogy to language.” But the analogy seems fragile. Chomsky has argued, powerfully if not conclusively, that simple trial-and-error imitation of adult speakers cannot explain the speed and confidence with which children learn to talk: some special, dedicated mechanism must be at work. But is a parallel argument available to Hauser? For one thing, moral codes are not assimilated with any special rapidity. For another, the grammaticality of a sentence is rarely a matter of doubt or controversy, whereas moral dilemmas pull us in opposite directions and leave us uncertain. (Is it O.K. to kill a perfectly healthy but morally despicable person if her harvested organs would save the lives of five admirable people who need transplants? Ten people? Dozens?)

Hauser hopes that his book will convince us that “morality is grounded in our biology.” Once we have grasped this fact, he thinks, “inquiry into our moral nature will no longer be the proprietary province of the humanities and social sciences, but a shared journey with the natural sciences.” But by “grounded in” he does not mean that facts about what is right and wrong can be inferred from facts about neurons. The “grounding” relation in question is not like that between axioms and theorems. It is more like the relation between your computer’s hardware and the programs you run on it. If your hardware were of the wrong sort, or if it got damaged, you could not run some of those programs.

Knowing more details about how the diodes in your computer are laid out may, in some cases, help you decide what software to buy. But now imagine that we are debating the merits of a proposed change in what we tell our kids about right and wrong. The neurobiologists intervene, explaining that the novel moral code will not compute. We have, they tell us, run up against hard-wired limits: our neural layout permits us to formulate and commend the proposed change, but makes it impossible for us to adopt it. Surely our reaction to such an intervention would be, “You might be right, but let’s try adopting it and see what happens; maybe our brains are a bit more flexible than you think.” It is hard to imagine our taking the biologists’ word as final on such matters, for that would amount to giving them a veto over utopian moral initiatives. The humanities and the social sciences have, over the centuries, done a great deal to encourage such initiatives. They have helped us better to distinguish right from wrong. Reading histories, novels, philosophical treatises and ethnographies has helped us to reprogram ourselves — to update our moral software. Maybe someday biology will do the same. But Hauser has given us little reason to believe that day is near at hand.’

Richard Rorty recently retired from teaching at Stanford. He is the author of “Philosophy and Social Hope.”

Jonathan Derbyshire’s Review

‘According to Marc Hauser, “morality is grounded in our biology”. We’ve heard this sort of thing before, of course – from evolutionary biologists, for instance, who claim that natural selection favours altruistic behaviour, since acting benevolently towards other people is a way of securing our genetic posterity. Some proponents of the evolutionary explanation go further, and infer from this that what seem to be our moral concerns aren’t our real concerns at all, and that what looks like altruism is in fact just a disguise for the operation of selfish genes.

Though Hauser himself believes that the moral machinery of human brains has been designed by the “blind hand” of Darwinian selection, he rejects such extreme interpretations. There’s no gene for altruism, he says, so we can’t derive specific rules for conduct from the structure of our DNA. And for that reason, we shouldn’t worry that our genetic inheritance leaves us trapped in an unchanging set of moral beliefs or judgments. On the contrary, our biology does not fix the range of possible moral systems, which is constrained only by history and culture. What that biology gives us is a set of very general principles on the basis of which we are able to develop one system of moral beliefs or another.

These general principles are at the heart of Hauser’s argument in Moral Minds. His contention, which he thinks amounts to nothing less than a “radical rethinking” of the nature of morality, is that human beings are creatures born with innate “moral instincts”. Because Homo sapiens is the only species to construct complex moral systems, morality has to be grounded in some distinctive property of the human brain – what Hauser calls a “moral organ” or “moral grammar”.

As the latter description suggests, Hauser’s inspiration here is the work done in theoretical linguistics by Noam Chomsky. Chomsky argues that the ability of children to learn to talk, which involves mastering highly complex rules of grammar, couldn’t simply be acquired by listening to competent adult speakers. There must be an innate “universal grammar” underlying different languages, deep structures that can be uncovered through painstaking comparative study.

Hauser builds on the “linguistic analogy” suggested by the philosopher John Rawls, who thought that a satisfactory account of our moral capacities would involve appealing to intuitive principles that we aren’t necessarily capable of articulating for ourselves. Just as we generate different, and mutually unintelligible, languages on the basis of universal grammatical principles, so, Hauser argues, there are deep moral “intuitions” that underlie cultural variations in social norms.

In order to uncover this “universal moral grammar”, Hauser devised a “moral sense test”. The test presented subjects with a number of so-called “trolley” problems, imaginary dilemmas dreamt up by philosophers and designed to tease out people’s moral intuitions. Imagine, for example, that you’re standing on a footbridge from which you can see a driverless tram hurtling in the direction of five people stranded on the track. The only way of stopping the tram and saving the lives of those people is to drop a heavy weight in its path. As it happens, a fat man is also standing on the bridge. Should you push the fat man to his death in order to stop the tram or leave him unmolested, in which case those on the track will die?

Hauser reports that only 10% of respondents said it was morally permissible to push the fat man from the bridge. From this and similar results, he deduces a universal “intention principle”, according to which intended harm is morally worse than harm that is foreseen but not directly intended. What is unclear, however, is why Hauser thinks data like these also license claims about the existence of a discrete moral faculty or “organ”. It is one thing to articulate principles that help to make sense of our intuitive responses to moral dilemmas, but quite another to conclude from this that such principles must belong to a particular region of the brain.

Moral Minds is full of fascinating reports on psychological experiments, few of which offer any obvious support for Hauser’s ambitious claims about moral grammar. This accounts, in part, for the book’s longueurs – that and the fact that Hauser’s rather colourless prose style is no match for that of scientific popularisers such as Steven Pinker or Richard Dawkins.

Hauser’s extravagant promise, in the prologue, to “explain how an unconscious and universal grammar underlies our judgments of right and wrong” is therefore not fulfilled. In fact, he comes close to acknowledging this in a somewhat deflating conclusion when he concedes that the “science of morality” is still in its infancy. And there is nothing here to suggest that this nascent discipline will conquer the “proprietary province of the humanities” any time soon.’

Jonathan Derbyshire is a philosopher and blogger

For 400 years the memory of Bruno has haunted the historians of science. But Bruno has his revenge every few weeks: about twice a month a new extrasolar planet is discovered orbiting a star: more than 250 such planets have now been documented. Bruno’s prediction of extrasolar planets has been vindicated. But one question lingers. Although the Milky Way may be teaming with extrasolar planets, how many of them can support life? And if intelligent life does exist, what can science say about it?

Some people claim that extraterrestrials have already visited Earth in the form of UFOs. Scientists usually dismiss the possibility of UFOs because the distances between stars are so vast. But last year the French government released a report by the French National Centre for Space Studies, which included 1,600 UFO sightings spanning 50 years, including 100,000 pages of eyewitness accounts, films and audiotapes. The French government stated that nine per cent of these sightings could be fully explained, that 33 per cent had likely explanations, but that it was unable to follow up on the rest.

The most credible cases of UFOs involve a) multiple sightings by independent, credible eyewitnesses and b) evidence from multiple sources, such as eyesight and radar. For example, in 1986 there was a sighting of a UFO by JAL flight 1628 over Alaska, which was investigated by the Federal Aviation Administration. The UFO was seen by the passengers of the JAL flight and was also tracked by ground radar. Similarly, there were mass radar sightings of black triangles over Belgium in 1989-90 that were tracked by Nato radar and jet interceptors. In 1976, there was a sighting over Tehran, that resulted in multiple systems failures in an F-4 jet interceptor. But what is frustrating to scientists is that, of the thousands of recorded sightings, none has produced hard physical evidence that can lead to reproducible results in the laboratory. No alien DNA, alien computer chip or physical evidence of a landing has ever been retrieved.

We might ask ourselves what kind of spacecraft they would be. Here are some of the characteristics that have been recorded by observers.

a) They are known to zig-zag in midair;

b) They have been known to stop car ignitions and disrupt electrical power;

c) They hover silently.

None of these characteristics fits the description of the rockets we have developed on Earth. For example, all known rockets depend on Newton’s third law of motion (for every action, there is an equal and opposite reaction); yet the UFOs cited do not seem to have any exhaust. And the g-forces created by zig-zagging flying saucers would exceed 100 times the gravitational force on Earth – the g-forces would be enough to flatten any creature on Earth.

Can such UFO characteristics be explained using modern science? In movies it is always assumed that alien beings pilot these craft. More likely, however, if such craft exist, they are unmanned (or are manned by a being that is part organic and part mechanical). This would explain how the craft could execute patterns generating g-forces that would normally crush a living being.

Any alien civilisation advanced enough to send starships throughout the universe has certainly mastered nanotechnology. This would mean that their starships do not have to be very large; they could be sent by the millions to explore inhabited planets. Desolate moons would perhaps be the best bases for such nanoships. If so, then perhaps our own moon has been visited in the past by a civilisation similar to the scenario depicted in the movie 2001: A Space Odyssey, which is perhaps the most realistic depiction of an encounter with an extraterrestrial civilisation.

Some scientists have scoffed at UFOs because they don’t fit any of the gigantic propulsion designs being considered by engineers today, such as ramjet fusion engines, huge laser-powered sails and nuclear pulsed engines, which might be miles across. But UFOs can be as small as a jet aeroplane, and can refuel from a nearby moon base. So sightings may correspond to unmanned reconnaissance ships.

Time is one of the great mysteries of the universe. We are all swept up in the river of time against our will. Around AD400, Saint Augustine wrote extensively about the paradoxical nature of time: ‘How can the past and future be, when the past no longer is, and the future is not yet? As for the present, if it were always present and never moved on to become the past, it would not be time, but eternity.’ If we take Saint Augustine’s logic further, we see that time is not possible, since the past is gone, the future does not exist, and the present exists only for an instant.

In 1990, Stephen Hawking read papers of his colleagues proposing their version of a time machine, and he was sceptical. His intuition told him that time travel was not possible because there were no tourists from the future. If time travel were as common as taking a Sunday picnic in the park, then time travellers from the future should be pestering us with their cameras. There ought to be a law, he proclaimed, making time travel impossible. He proposed a ‘Chronology Protection Conjecture’ to ban time travel from the laws of physics in order to ‘make history safe for historians’.

The embarrassing thing, however, was that no matter how hard physicists tried, they could not find a law to prevent time travel. Apparently, time travel seems to be consistent with the known laws of physics. Unable to find any physical law that makes time travel impossible, Hawking recently changed his mind. He made headlines when he said, ‘Time travel may be possible, but it is not practical.’

Time travel to the future is possible and has been experimentally verified millions of times. If an astronaut were to travel near the speed of light, it might take him, say, one minute to reach the nearest stars. Four years would have elapsed on Earth, but for him only one minute would have passed, because time would have slowed down inside the rocket ship. Hence he would have travelled four years into the future, as experienced here on Earth. (Our astronauts actually take a short trip into the future every time they go into outer space. As they travel at 18,000 miles per hour above the Earth, their clocks beat a tiny bit slower than clocks on Earth. The world record for travelling into the future is held by the Russian cosmonaut Sergei Avdeyev, who orbited for 748 days and was hence hurled .02 seconds into the future.) So a time machine that can take us into the future is consistent with Einstein’s special theory of relativity. But what about going backwards in time?

If we could journey back into the past, history would be impossible to write. As soon as a historian recorded the history of the past, someone could go back into the past and rewrite it. Not only would time machines put historians out of business, but they would enable us to alter the course of time at will. If, for example, we were to go back to the era of the dinosaurs and accidentally step on a mammal that happened to be our ancestor, perhaps we would accidentally wipe out the entire human race. History would become an unending, madcap Monty Python episode, as tourists from the future trampled over historic events while trying to get the best camera angle.

But perhaps the thorniest problems are the logical paradoxes raised by time travel. For example, what happens if we kill our parents before we are born? This is a logical impossibility. It is sometimes called the ‘grandfather paradox’.

There are three ways to resolve these paradoxes. First, perhaps you simply repeat past history when you go back in time, therefore fulfilling the past. In this case, you have no free will. You are forced to complete the past as it was written. Thus, if you go back into the past to give the secret of time travel to your younger self, then it was meant to happen that way. The secret of time travel came from the future. It was destiny. (But this does not tell us where the original idea came from.)

Second, you have free will, so you can change the past, but within limits. Your free will is not allowed to create a time paradox. Whenever you try to kill your parents before you are born, a mysterious force prevents you from pulling the trigger. This position has been advocated by the Russian physicist Igor Novikov. He argues that there is a law preventing us from walking on the ceiling, although we might want to. Hence, there might be a law preventing us from killing our parents before we are born.

Third, the universe splits into two. On one timeline the people whom you killed look just like your parents, but they are different, because you are now in a parallel universe. This latter possibility seems to be the one consistent with the quantum theory.

The film Back to the Future explored the third possibility. Doc Emmett Brown (Christopher Lloyd) invents a plutonium-fired DeLorean car, which is actually a time-machine for travelling to the past. Marty McFly (Michael J. Fox) enters the machine and goes back and meets his teenage mother, who then falls in love with him. This poses a sticky problem. If Marty’s teenage mother spurns his future father, then they never would have married, and he would never have been born.

The problem is clarified a bit by Doc Brown. He goes to the blackboard and draws a horizontal line, representing the timeline of our universe. Then he draws a second line, which branches off the first line, representing a parallel universe that opens up when you change the past. Thus, whenever we go back into the river of time, the river forks into two, and one timeline becomes two timelines, or what is called the ‘many worlds’ approach.

This means that all time-travel paradoxes can be solved. If you have killed your parents before you were born, it simply means you have killed some people who are genetically identical to your parents, with the same memories and personalities, but they are not your true parents.

So, between group behaviour would override within group behaviour. This depends crucially on group selection. This approach was largely discredited by the 1960s and other theories were developed, such as kin selection; evolutionary game theory; and selfish gene (extended phenotype) theory. These are all theories that seek to explain apparent altruism through individualistic behaviour. The idea that there was such a thing as society as an organism was comprehensively rejected.

This concept has been recently challenged and what is called multilevel selection is gaining ground. It helps to explain not just tribal behaviour but animal behaviour, multi-species ecosystems, the nature of religion and rise and fall of empires, among other things. The revision has been made possible by the massive increase in computing power that has enabled complex models to be studied.

Experiments with microbes have shown that between-group evolution is very powerful. Observations in the field with lions and other creatures bear this out. Earlier theories trying to explain altruism through individual advantage had failed because they did not prove what they set out to do. Hamilton (kinship theory) and Dawkins (extended phenotype theory) have since admitted this.

Multilevel selection suggests that groups behave like organisms, which are a collection of co-operative cells. Hamilton’s original claim that this was to do with kinship has been shown to be wrong.

There are many examples in the article on how multilevel selection applies to humans. For instance, we enforce a certain level of egalitarianism on the group so that one individual cannot exclusively dominate all. This allowed teamwork to develop and helped facilitate between group activity; and it is this ability that has led to our world-wide dominance.

The article also says that within group selection has not been eliminated only suppressed, which explains the tensions existing between selfishness and altruism. It ends with a quote adapting Rabbi Hillel, ‘Selfishness beats altruism within groups. Altruistic groups beat selfish groups. Everything else is commentary.’

The proposition is that quantum weirdness – by that it means uncertainty and, particularly, entanglement – is a manifestation of something, rather than being a fundamental property of particle physics. The reason for the search is not new because quantum theory is at variance with Einsteinian relativity. Einstein personally hated QM but could not disprove it. So, quantum theory stands up, as does relativity, but they are in contradiction in some very important aspects, such as non-locality. Relativity states that nothing travels faster than light but QM says that two entangled quantum entities, such as photons, affect each other instantaneously, even if they are separated by the width of the universe.

John Bell, the Irish physicist, tried to identify some kind of underlying truth that would reveal entanglement to have been present all along and not the result of observer action. This was more than 40 years ago and it was called, ‘Hidden Variables.’ He failed in his endeavours, so we have been stuck with this apparent contradiction ever since.

He used algebraic maths to do his calculations, which is commutable (i.e. gets the same result whichever way one writes the equation). Christian thinks that this misses a trick and he uses a more complex type of maths, which is non-commuting, called quaternions. This reveals the possibility of a deeper, underlying truth, which is consistent with classical physics.

In summary, QM as it now stands shows the universe to be subjective and observer-driven, whereas this new approach leads to the possibility that the world is objective and deterministic.

I hope I have got that more or less right. Can you scientists and mathematicians correct me if I have misled the jury.

Let the discussion commence.