Star man who blew our minds

When the night skies above Sri Lanka inspired a young boy to think about galaxies far, far away, they helped changed the way we look at life.

For Chandra Wickramasinghe was so inspired by the "magnificent" canopy that stretched across his homeland, he developed a yearning to investigate.

The little boy went on to not only investigate, but to develop new theories of life, the universe and everything, which have moved from being controversial and left-field into mainstream science. With many popular books and TV appearances behind him, he is arguably the best-known scientist at Cardiff University.

"When I was a child growing up in Colombo I would look up at the sky and think about the stars and life among the stars," Wickramasinghe said. "At 15 I liked to write poetry and one I remember went, 'Amongst the myriad stars/I stand alone/and wonder how much life and love there was tonight'.

I always felt quite deeply connected with the universe and was thinking about our place within it before I even started astronomy." Now, as Wickramasinghe prepares to retire next month from his role as Cardiff University's professor of applied mathematics and astronomy, he will be celebrated in a BBC Horizon programme and a special conference, entitled "Progress towards unravelling our cosmic ancestry".

Wickramasinghe's work and refers back to his 1974 theory, which first proposed that "dust in interstellar space and in comets was largely organic" - in short, that life on earth may not have originated here but somewhere else in the cosmos.

The idea attracted comment and criticism, challenging a basic "holy grail" of science. But Wickramasinghe was equipped and qualified for the backlash.

Born in 1939, he was educated at the University of Ceylon, achieving a first-class honours degree in mathematics. He won a Commonwealth scholarship to study at Trinity College, Cambridge, and followed in the footsteps of his astronomer father, an inspirational scholar whose books the young Wickramasinghe had devoured.

Productive and controversial

At Cambridge, he begin a long, productive and often controversial partnership with the late Sir Fred Hoyle, a renowned astronomer credited with the first use of the term "Big Bang" (he intended it dismissively as he did not believe the theory), who would later win the Crafoord Prize from the Royal Swedish Academy of Sciences, an award similar to the Nobel Prize.

Wickramasinghe published his first scientific paper in 1961. He was awarded a PhD degree in mathematics in 1963 and elected a Fellow of Jesus College, Cambridge, in the same year. He arrived in Cardiff in 1973 - then, at 33, the university's youngest professor - and formed the Department of Applied Mathematics and Astronomy.

Here he continued work started in Cambridge into the nature of interstellar dust - the strange swirl of material seen in photographs of the Milky Way - and went public with his radical findings the following year. He and Hoyle had begun their studies into the dust by going back to basics, reinvestigating the "old theories" of how life started on the earth.

"We concluded there was no firm evidence to regard the idea that life definitely started on the earth as proven fact," he said. "The fact that life exists on the earth does not mean that it started here.

"To look at it another way, a Celtic language is spoken in Wales but it didn't originate in Wales. The Celts came from mainland Europe many thousands of years ago." The theory they eventually produced - based on panspermia, the idea that life began in space - created shockwaves which are still reverberating through the scientific community today. In describing it in simple terms, something of the wide-eyed young boy gazing at the stars above a Sri Lankan home returns.

"On a dark cloudless night we see the Milky Way arching across the sky," he said. "In between the billions of stars there are dark, obscuring clouds in a variety of shapes, for example, the horsehead nebula.

"These clouds consist of billions of microscopic dust particles and it is from such clouds that stars, planets and comets form.

"Before my work it was generally thought that these cosmic dust particles were made up of ice particles, similar to the particles in the cumulous clouds of the earth's atmosphere.

"My research over the years showed that the dust was largely made of carbon, and, moreover, that the carbon was in the form of substances that could be connected with life.

"Even more significantly, a component of the cosmic dust could be in the form of freeze-dried dormant bacteria." The discovery, he said, was made by "process of elimination". "We excluded non-life, inorganic compositions for the dust, and what was left was the only remaining alternative; unbelievable, but still inevitable." To many, it remained unbelievable.

"The idea of life being centred on the earth, and originated on earth, has now to be abandoned," said the professor, explaining the scope of the rethink needed by the scientific - and wider - community.

"Life is a truly cosmic phenomenon. We are part of a connected chain of being that connects us - life on earth - to the remotest parts of the cosmos."

Sense of drama

With a sense of drama, which has helped ensure wide news coverage for his theories, he added, "Cosmic dust contains our genetic ancestors. We now know that the first life on the earth appeared about 3,800 million years ago, when the earth was being heavily bombarded by comets.

"Comets brought the first life onto the earth at this time. Subsequent developments connected with the further evolution of life must also have been connected with the continuing arrival of bacteria from space.

The extreme hardihood of bacteria, including their resistance of intense cold and radiation, all point to their cosmic origins." The theory divided opinion and exposed Wickramasinghe to some ridicule from "mainstream science". Many wondered, and some continue to wonder, whether Hoyle and his younger partner had not "gone off the deep end".

The pair were criticised for "inconsistencies" and one leading scientist described the theory as "shameless pseudoscience".Hoyle's support got him through. "It was really quite vicious criticism in the early years," he said.

"But I faced it because I had this very great man - perhaps the most eminent astronomer of the 20th century - alongside me, and for him to support these views and encourage me was a source of great strength.

Otherwise I would have succumbed to the harsh criticism." On Hoyle's death, Wickramasinghe continued to explore the theory's implications further and just two years ago, working with Professor Max Wallis, he produced a fascinating follow-up, which suggested that after arriving on earth, life - in its most basic form - could continue to spread around the galaxy.

The new theory suggested that comets striking earth could create a "splash-back" effect, throwing materials containing micro-organisms back out of the planet's atmosphere.

While some of the material would be sterilised by heat and radiation, the scientists argued, a "significant fraction" would survive.

As the earth and solar system move around the centre of the galaxy every 240 million years, the bacteria would infect hundreds of millions of developing planets. So, said Wickramasinghe and Wallis, "the transfer of earth life across the galaxy is inevitable".

Wickramasinghe's theories were propelled further forward this year when a front-page report by the New Scientist looked at claims by Indian scientists that 50 tons of microbes fell to earth in 2001 in the form of a red rain.

Initial research showed that the "rain" contained alien red-coloured living cells and samples were sent to Cardiff. Could the shower have been caused by a passing comet depositing extraterrestrial organisms over our planet? His investigation continues, although he said it is "more than likely" that the cells came from space.

"If it is confirmed that this has come from space it shows that this is an on-going process. That it happened four billion years ago to create life on earth and life is still being moved through the cosmos on comets." Wickramasinghe, now 67, has received many accolades. In 1986, with Sir Fred Hoyle, he was awarded the International Dag Hammarskjold Gold Medal for Science.

He has been honoured by universities in his homeland and in Japan, and has received a national honour from the president of Sri Lanka. The father-of-three has also found the time to write more than 25 books, 350 scientific papers and award-winning poetry.

Since 2000 he has been director of the Cardiff Centre for Astrobiology, a role he will continue following his retirement.

His retirement as a teaching professor will be marked with a conference attended by about 40 scientists from around the world.