POWER OF REASON: Simon Singh (top) and the cover of his new book (above)

When it comes to explaining science to the masses, most journalists are at a disadvantage because they do not know enough about science. Scientists cannot do this job either because although they are experts in their own fields, the vast majority cannot write. This is where Simon Singh, one of Britain?s most admired young science writers, is in a class of his own.

He has done many TV and radio programmes on science and his first book, Fermat?s Last Theorem, about a ?notorious mathematical problem?, was the first maths book in the UK to become a number one bestseller. The documentary which preceded the book won Simon a BAFTA award, the British equivalent of the Oscars.

His second book, The Code Book, was a history of codes and code-breaking. ?We live in the information age and one of the best ways to protect information is to encrypt it,? he says.

Simon has just come out with his third book, Big Bang (Fourth Estate; ?20), which is about ?the most important scientific discovery of all time and why you need to know about it?. It is the story of the origin of the universe, how everything was compressed into an incredibly heavy pin head which exploded with a ?Big Bang? ? and now the billions of galaxies in the universe are receding rapidly from each other.

In setting out to explain how the universe began to the ordinary reader, Simon quotes a good authority, Albert Einstein, who once remarked: ?The most incomprehensible thing about the universe is that it is comprehensible.?

One reason why Simon is able to take complicated ideas and explain them simply is that he is himself a scientist. When we meet in a Notting Hill caf?, not far from where he lives in London, he reminds me that his first degree was in physics from Imperial College, London. He then did his PhD in particle physics at Cambridge when he had to spend much of his time doing nuclear experiments at CERN in Switzerland. ?Particle physics was great fun,? he remembers of his time at Emmanuel College in Cambridge.

He knew from the very start that his life would be in science. ?At the age of nine I declared that I wanted to be a nuclear physicist,? he says. His was not a particularly academic family. His grandfather, who came from rural farming stock in Punjab, arrived in Somerset in 1938, when there were not too many Indians in Britain, least of all in rural England.

Simon gets quite emotional when he talks about his attachment to science. ?Science can keep us warm, science can feed us, science can keep us healthy ? that is really technology. But science can also give us amazing ideas and that is what I love most about science.?

He believes that a science degree gives students greater reasoning power. ?Once you have training in science, your training helps you solve problems in general, not just problems in particle physics. You have an ability to dissect and decide which bits to take when solving problems.?

This is where he comes to the heart of our interview. He laments that the number of British schoolchildren who are going on to study maths and physics at university is plummeting. It is the same at school where there aren?t enough science teachers to pass on a love of science to pupils. He contrasts what he believes to be a rosier picture in India with the depressing reality of Britain ? and this is why he earnestly hopes that some child who reads his book on the Big Bang might be enthused into taking up science as a fit subject for study.

?In India people clearly see science as the way forward, whereas in the West it is perceived as causing the problems of GM (genetically modified) foods, cloning and animal testing,? he observes. ?Because of that, fewer and fewer people go on to study science and yet Britain needs scientists, innovators, inventors.?

He regrets all this has a knock-on effect. ?Fewer people are graduating in science and technology. They go and get jobs in industry and none of them thinks of becoming a teacher, which is such an important skill. Fewer people go into teaching and therefore fewer pupils are inspired to study science, so there are even fewer graduates and of the few who graduate, none of them goes into teaching.?

The future for Britain because of the shortage of scientists is grim, he stresses. ?At the moment, we are on a downward spiral. The British government had a big maths inquiry this year to look at why people are not doing maths any more.?

He remembers an anecdote which illustrates the erosion of Britain?s once cherished scientific culture. ?Newsnight (a BBC flagship programme) went to IIT Chennai three years ago and the reporter said, ?Oh, we are thinking of inviting more Indian scientists and mathematicians to work in England because we don?t have enough people to work in the information age.? And those students just laughed ? ?Why would we want to go to England? We want to go to California. If we had to leave India, we wouldn?t want to go to England.??

When he applied to do physics at Imperial it was understood he would require maths at A level in his school-leaving exams. ?Otherwise it would be a joke,? he adds. The crisis has become so deep that ?now you have universities who accept students to do physics who don?t have A-level maths because they don?t have enough people wanting to do physics.?

He finds it utterly depressing that in the country of Isaac Newton, there are today more students applying to do a degree in psychology than in physics. He thinks the reporting of science stories in the press does not help.

?I don?t know about India but we have a frustrating press in this country,? he goes on. ?It is quite happy to spend two pages telling you about all the bad things about GM foods but it won?t ever bother telling you all the good things.? He predicts the long-term consequences of Britain?s anti-scientific culture. ?We won?t have innovation, the economy will go down.?

Simon?s mission is to make children excited about science. This is why there is always an underlying theme to his books. ?I wrote Fermat?s Last Theorem to explain why mathematicians do what they do and how they do it,? he says. ?The Code Book is about the application of technology and how it affects our lives. This book about the Big Bang is on how science works, how new ideas are put forward, how they are accepted, challenged, proved.?

A hundred years ago, ?nobody knew anything about the universe really,? he tells me. ?Cosmology was not a serious subject and now we can put dates of 13.7 billion years on the age of the universe, say how the stars were created, how the galaxies evolved, we can explain so many things. New questions arise but we are all moving forward. Indian astronomers are world class.?

Simon?s great gift is to be able to explain fundamental ideas about how the universe began but in simple fashion which even children would understand. ?I decided to write a book about the Big Bang theory because it is one of the pinnacles of human achievement,? he states. ?I wanted people to understand the theory and to appreciate why cosmologists are confident that it is an accurate description of the origin and history of the universe.?

He says: ?The story begins with the theoretical foundations laid by Einstein and his General Theory of Relativity. But it was Georges Lema?tre, a Catholic priest from Belgium, who proposed the idea of a universe born at a single instant in the past ? ?a day without a yesterday? ? and expanding outwards from that moment.?

And the story continues: ?Edwin Hubble (an American living in Oxford) made a remarkable discovery. Using some of the biggest telescopes ever built, he found that all the galaxies were racing apart from each other. Not only that, but the further away a galaxy was, the faster it was moving. Running the clock backwards led to a disturbing conclusion. There must have been an instant in the distant past ? that day without a yesterday ? when everything in the universe exploded into being out of a single point in space. The evidence was pointing towards a Big Bang. A moment of creation.?

However, ?many cosmologists were reluctant to accept a theory that smacked of divine creation. Hence, Fred Hoyle, working with the Indian, Jayant Narlikar, proposed an alternative Steady State model in which the universe was both expanding and eternal. However, even though Hoyle was an opponent of the Big Bang theory, it was he who christened the theory, referring to it disdainfully in a radio broadcast as ?this ?Big Bang? idea?. The name stuck, and so did Hoyle?s opposition to the theory.?

He adds: ?Although Hoyle and Narlikar were wrong they made a major contribution.? Simon sets it out: ?The stage was set for a major battle between the two camps ? Bang Bang versus Steady State. It would take the rest of the 20th century to resolve the conflict. The battle for cosmic truth would involve politics, religion, bitter disputes, nuclear physics, satellites, telescopes, a supposed echo from the Big Bang, and remarkable serendipity, resulting in one of the greatest adventures in the history of science.?

A child would probably ask: ?But, sir, what was there before the Big Bang?? Simon?s reply is: ?At the Big Bang, space was created and time was created. If time was created at the Big Bang, you can?t ask what happened before because there was no ?before?. Because there was no time.?