Astrophysicist Trinh Xuan Thuan (below) tells Stella Hughes about himself and the cosmos.

Cosmic spaghetti, galactic sponges and time machines may all sound rather frivolous, but for the purveyor of these images of the universe, Trinh Xuan Thuan, professor of astrophysics at the University of Virginia, popular science is a serious matter.

Since 1980, Trinh Xuan has regularly taught a course at Virginia called "Astrophysics for the Poets''. On it, first and second-year humanities students learn that telescopes are machines for travelling back in time, towards the origins of the universe: a gentle way into the role of the speed of light in the mass energy equation of the theory of relativity.

A specialist in extragalactic astronomy, Trinh Xuan describes how the universe is made up of clusters of galaxies, shaped like pancakes or forming walls, between which are huge vacuums that could be travelled without ever entering a galaxy, like a journey through the cavities of a sponge.

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"Astrophysics for the Poets is the course I like teaching the best. It's a stringent test to hold the interest of students who are just rounding out their scientific culture, whereas science students are a captive audience and more forgiving,'' he commented.

Trinh Xuan is not simply testing his own capacity to hold an audience. "I do my best teaching these classes because I think these students might become decision-makers. Perhaps some will end up in Congress and vote for funding for this kind of thing.''

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"I try to show them that this may not benefit their pocket books but it does make man greater because it connects him to the whole cosmos,'' he explained. For Trinh Xuan that connection is not only scientific, but also spiritual and creative - another reason why he enjoys popularising his discipline.

"Science students would see literary references as a waste of time. My course allows breadth, bridging other fields of knowledge, creative fields like literature and poetry,'' he said.

Astrophysics for the Poets "hones the skills'' he put to use in The Secret Melody, a best-selling paperback in France first published in 1988 which Oxford University Press will publish in English later this year.

Already out in English, The Universe, The Big Bang and After, (Thames and Hudson) gives an idea of his habitual range of references. The insights of Edgar Allan Poe and Saint Exupery's Petit Prince, of Thomas Aquinas and Kant, feature alongside those of quantum theory to provide an account of the universe for a reader unable to cope with equations.

For the audience avid for exploration of all possible meanings of the cosmos, the scientist explaining white dwarves readily switches to the private individual prepared to offer up his personal philosophy with its blend of three cultures and its Buddhist foundation.

As a lycee student in post-French Indochina, Trinh Xuan was equally good at literature, philosophy, mathematics and physics. A scientific career was more prestigious than a literary one but still unusual in Vietnamese society and he is grateful to his parents for not pushing him down the well-trodden path towards the more lucrative professions of lawyer or doctor.

Those mid-1960s school years were relatively undisturbed by the escalating Vietnam War, although US B52s thundered around Saigon and the family sheltered from crossfire in a trench in the garden through two CIA-backed coup attempts at the nearby presidential palace.

The son of a senior civil servant who had fled south to Saigon from communist rule, he was raised in a Francophone environment. In 1966, his double-starred baccalaureat was to have taken him to Paris and preparatory class for l'Ecole Polytechnique.

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But then the Saigon government cut off relations with France, angered by President de Gaulle's call for a US withdrawal. Trinh Xuan ended up at the Lausanne Polytechnique and discovered he was not cut out to be an engineer. Nor was he cut out for a cold climate. So when all three US universities he wrote to in very poor English offered him a place - and a grant - after a series of tests, he chose sunshine and Caltech, the California Institute of Technology, over MIT and Princeton, without even knowing of its record in astrophysics. Although his original plan was to be a physicist, Caltech and its huge telescopes, its links with Edwin Hubble, the recent discovery of quasars by Caltech professor Marteen Schmitt, all drew him to cosmology.

From there, it was on to a PhD at Princeton and a professorship at Virginia in 1976 - all parts of a pattern of personal destiny which Trinh Xuan believes in as much as he does in there being a "design'' behind the creation of the universe.

His PhD was in interstellar mediums, a strongly theoretical subject, but since then, he has worked on the formation and evolution of galaxies. "Doing theory, you sit and simulate on computer to try to understand what other people observed. I really enjoy observation, real contact with the skies, using a telescope and collecting light, then making models from it,'' he explained.

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His choice of concrete reality over abstract entities, of a multifaceted approach to man's link with the cosmos, puts him poles apart from the great theoretical astrophysicist Stephen Hawking. But just as Hawking's account of theories of time fill the reader with mind-stretching wonder at his concepts, Trinh Xuan's skill in conjuring up concrete images of the approach to a black hole or the birth of a galaxy conveys his own strong sense of awe at the beauty and the architecture of the universe.

Presumably, wonder at the marvels of the universe is almost a job requirement for astrophysicists, as they work their way back to within 10-43 seconds of the big bang and beyond. A Brief History of Time and The Secret Melody, written and published almost in parallel, are remarkably complementary.

Hawking gets impatient with the strong version of the anthropic principle (the idea that the universe necessarily led to the emergence of a conscious observer), while Trinh Xuan is frustrated by purely mathematics-based theories which cannot be tested by present-day science - the one for example which posits the development of cosmic cords before that 10-43 second barrier.

"To test a theory of those first fractions of a second after the big bang, you would have to build a particle accelerator from earth to the nearest stars,'' he explained.

Describing why black holes will never yield up their secrets - because, on approach, our flesh would be drawn in like cosmic spaghetti, then our bones would break up and even if that did not happen no information could be sent back once we entered the black hole - he concludes that black holes "exercise cosmic censorship''.

The remark is thrown off with a smile and raises a laugh from his audience, yet there is just a hint of exasperation that this secret will never be knowable as a concrete reality. However, while theoretical physics searches for a single, unifying theory, Trinh Xuan remains satisfied that human consciousness can never discover "the secret of everything''.

"The universe is always so much more imaginative than the human mind because it can construct things that human imagination would never conceive of,'' he said. This sense of humanity's ultimate littleness allows his personal belief in a grand design behind the universe, with a central role for human consciousness, to steer clear of anthropic arrogance.

"Modern cosmology has reintegrated man in the universe,'' he commented, pointing to the fact that however many computer simulations are tried out to make model universes, they are always sterile. Only the conditions present at the start of our universe have been found to lead to the emergence of life and, ultimately, consciousness.

Ironically, modern cosmology is now becoming so sophisticated, so dependent on huge instruments and complex computer programmes, that direct contact with the cosmos is, increasingly, lost. Astronomers are less and less often to be found, eye to a telescope, under a starry night sky. Astronomers do not even need to know the sky any more,'' he said. "For example, I send my observation programme by modem, months ahead, to staff at the Baltimore space telescope center who manage Hubble, where it is matched up with other requests to make the most efficient use of the telescope.'' Trinh Xuan uses Hubble, the Kitt Peak observatory and the VLA radiotelescope in New Mexico. Competition for access to Hubble is fierce and only one in eight applications is accepted.

For a populariser like Trinh Xuan, it is particularly important to keep a high profile in his discipline. "There is always a suspicion that the popular science writer is not doing enough research,'' he noted. Although Trinh Xuan does not miss the freezing cold of nights spent on mountain tops in his student days, he says today's students are "in danger of becoming enamoured of the computer screen. They feel they are completing work just by doing something on screen, while the real advance in knowledge is still when you sit and work something out with your brain and a pencil.''

Even more worrying are today's cuts to research funding in fields like astrophysics and astronomy, where there are no real applications. Trinh Xuan points out that US spending on astronomy takes up just 0.01 per cent of the budget. "The worry is not just for current research, it also cuts off the best and brightest minds from going into science because they see the dearth of jobs and tenure,'' he pointed out.

Yet however severe the cuts, he said, "I would never defend science for practical returns before politicians - it has to be for the glory of the human spirit. Astronomy helps us transcend the weight of our bodies and the brevity of our lives.'' Popular science writing helps Trinh Xuan overcome the isolation of the astrophysicist working mainly alone and writing scientific papers read by just a handful of fellow specialists. It also allows him to and draw parallels with Seurat's paintings.

"If the earth were populated only by scientists, it would be a very dull place!'' he laughed. What if he had to chose between conflicting scientific and Buddhist accounts of a phenomena in the universe? He would choose the science.

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