Humans are story-telling animals. Science itself is a kind of story-so-far, in the unfolding adventure of how we got here and where we are going. Scientists and journalists both seek the truth, with the following caveat. Scientists go on until they are convinced they have the truth. Journalists tend to stop looking as soon as they have a story.

This is a big distinction, but the two callings remain compatible. Scientists and journalists also have many things in common: the most obvious is a kind of constructive curiosity. Both regard the words 'I don't know' as a starting point, not an admission of defeat. Both frame hypotheses, and then look for evidence. Both do literature searches, to see if somebody else has proposed a better answer, or inadvertently opened an interesting line of enquiry. Both write in a form acceptable to their destined journals, and both undergo peer review before publication. Both take pride in getting the story right.

There are also some critical differences. Scientific research takes as long as it takes - months, years, or until the research grant runs out - and so does the peer review and publication. In a daily newspaper, however, the entire process happens between 10.00a.m. and about 9.00p.m. of one working day. Errors certainly occur. But newspapers on balance get a very large number of things right. Scientific papers are in theory as sound as time and diligence can make them, but inevitably some of these turn out to be in error too. So the time taken is not the most important difference.

The true distinction reveals itself after publication. A scientific paper can be circulated, indexed and cited, and serve the laboratory's, or the author's primary purpose, without being read at all. Its existence on a database is itself an announcement: that the author has cornered a patch of intellectual territory, or that a laboratory has been able to generate yet another publication from the same set of data, or that the research institution is keeping up in the great publish-or-be-damned marathon. A scientific paper can do all these things without being read by anyone, and still be deemed a success. A newspaper report that was read by nobody would be a complete disaster. A newspaper report must be balanced, fair, accurate and topical but, above all, it must be read.

So a scientific paper may be couched in the language of advanced scholarship. Its audience expects such language. It may not read the paper, but the language itself will not be the obstacle. Journalists on the other hand know that the decision to stop reading a newspaper article happens in a mere fifth of a second - it is hardly ever a conscious decision, usually just a cessation of attention - and that the careless use of words like mitochondrion, isostasy, phenotype, functional genomics, or albedo is guaranteed to send the reader to the sports pages, or the television reviews. Science is difficult - it is done by PhDs, rather than dilettantes - and people who make new discoveries must coin new words for them, which makes science even harder to follow. But journalists find their stories not in the process of science itself, but in what it has achieved or what it might one day deliver. These things, paradoxically, can mostly be described in quite ordinary language.

But language remains a problem. Even if science writers manage to avoid the prickly, keep-off language of science, they still have to deal with the concepts that the words describe. Some of these - cosmic inflation, the biochemistry of a single cell, ocean floor magnetic anomalies - have no parallel in lay experience. Journalists also tend to fall back on comforting analogy and reassuring metaphor, which is why Pandora's box, the Holy Grail, the magic bullet and Frankenstein's monster have all been monstrously overworked. Such phrases are not the currency of thought: they are substitutes for thought. They too represent a barrier to the public understanding of science.

But language is not the only barrier. Most people have an ambivalent attitude to science. I do not mean that people fail to see the merits of science. I mean that hindsight affects our view. For someone born in the 1940s and at school until the 1950s, science can be seen as a palpable force. At the end of the 1940s, there were many households without indoor sanitation, some without electricity, nearly all without refrigeration and hardly anybody had a car. Telephones were rare, television almost unknown. By the end of the 1950s almost all houses had running water, bathrooms, refrigerators and television; ownership of a car was an achievable ambition and there were huge waiting lists for the telephone. At the end of the 1940s, it was still possible to be crippled by polio, enfeebled by tuberculosis, disfigured by smallpox or killed by septic infection. At the end of 1950s, these things had all but ceased to happen. People were enriched by the science and technology of Pasteur, Lister, Jenner, James Logie Baird, Thomas Edison, Alexander Fleming, Alexander Graham Bell and William Morris of Oxford, all of whom had been born in the previous century or even earlier. In their time, of course, most people either knew nothing of Pasteur or Fleming or Baird, or they thought them eccentric, misguided or mad. The point I want to make is that people do not now think of using disinfectant, or taking a prescription, or turning on a television set as science - they think of it as common sense. There are, however, other products of science that matured during those two decades after the war: they were radar, space rockets and nuclear weapons. They helped to fuel a febrile Cold War. So around about the time we all got televisions and refrigerators we also got the news that we might have just four minutes' warning of continent-wide incineration. We did not think of those things as common sense. We thought of them as science.

We still live with this bifocal vision. Science journalists and scientists, to judge from some books written by scientists, share the ambivalence. The DNA revolution - cloning, stem cells, genetic engineering and all that - is simultaneously presented as a magic tablecloth of medical marvels and a kind of moral minefield: just count up the number of times you read or hear about playing God, playing with fire, slippery slope, ethical morass, thin end of the wedge, genie out of the bottle and (oh yes) Pandora's box. Are people wrong to feel uneasy, uncertain or downright worried about things to come? Hope and fear are useful emotions. Complacency is not.

Meanwhile, scientists will go on making incomplete sense of the world one step at a time, and journalists will go on telling stories. Journalists are like Sheherezade in the Thousand and One Nights. She had to tell the caliph stories every night, and end with a cliffhanger that would leave him wanting more. If she failed to keep him hooked, she perished under the headsman's axe. Journalists tell stories, and if readers don't read them, the journalists are out of business. To restate the opening thesis: newspapermen and scientists are both in pursuit of truth. They have that in common. There is a catch. Scientists are worried about being right. Journalists are worried about being read. Between the two, there remains some room for misunderstanding.

External links

• Tim Radford: Contact details and biography