Perhaps I should point out at the start that for much of my career I have placed the word "scientist" in the box labelled "occupation" on most important paperwork. I used "ecologist" at one stage, but found that it raised too many questions in the cold mind of underinformed officialdom about my potential for left-wing tendencies and antinuclear protest. For a time, therefore, I switched to "agricultural scientist" as being potentially more respectable until I discovered that this resulted in having my shoes, clothes and luggage fumigated by zealous immigration officials at remote but memorable border crossings. So please understand that I have suffered for my trade.

Over time, I have noticed a difference in the feedback you get when - in response to the opening line when sitting at the bar: "What do you do, then?" - I have announced myself as a scientist. Twenty years ago the most common attitude was one of polite, if somewhat remote, interest, but in the past few years it has become much more common in this situation to be accused of being responsible for everything from inducing climate change to the creation of dangerous and unnatural genetic constructs.

This suggested to me that when the word "scientist" is mentioned people see a particular, and not overwhelmingly positive, set of images in their heads. Until recently it would have been a long and complex task to deduce with any rigour what those images were.

Today, however, we - or rather you - can do the research in a few keystrokes, and we can make this discussion a bit more interactive. So - stop reading this for a moment and find a web browser. Go to your favourite search engine and run an image search on "scientist". I'll wait here until you get back.

É«ºÐÖ±²¥

Interesting, isn't it? When I carried out this exercise, I found that more than half the first page held images of either archetypal mad scientists - white-coated, bespectacled, mentally deranged characters poring over fuming retorts of ghastly chemicals - or similarly ironic yet iconic images. Of the first 20 pictures in my search, only three were representations of "real" scientists. Now, I know what you are thinking, and you're right. This exercise itself entirely fails to satisfy as a demonstration of scientific method: it has no control, it cannot - by the very nature of the world wide web - ever be repeated in exactly the same way, and no formal proposition was made in advance which was being tested by the experiment. Valid criticism - but please accept for a moment the premise that there may be a public image of the career scientist that may not be the one preferred by practitioners of the profession.

So how has this situation arisen, and does it matter? My contention - and this is a wildly unscientific view based on observation, drunken conversations and gut feeling - is that the popular image of the scientist is based so closely on fictional representations of science and - in particular - on science fiction that the public view of science itself is becoming just a mirror of these fantasy creations.

É«ºÐÖ±²¥

You're sceptical? Let's look at some of the history. You could argue, and many people do, that science fiction began in 1816 with a young Mary Shelley spending a boring, wet summer in the Italian Alps - and writing Frankenstein to while away the time. In doing so, she helped establish a vivid, classical picture of the mad scientist - someone divorced from immediate reality, isolated from loved ones, morally bankrupt but still convinced of his essential superiority - that has endured to this day.

After this florid start, the scientist as emotionless, soulless demon was carried forward into the 20th century through popular novels such as those of H.G. Wells - whose character Dr Moreau, a vivisectionist of startling brutality ensconced in his truly terrifying House of Pain, did little to help develop a benevolent public view of the research scientist.

Marginally less visceral in his research techniques, but still far from approachable, is Arthur Conan Doyle's Professor Challenger. He is a man of strong views, especially as regards the communication of his research - and the role of journalists in particular. We are told in The Lost World that he was the man "who broke the skull of Blundell of the 'Telegraph'", that he was "just a homicidal maniac with a turn for science" and that he exhibited "insufferable rudeness and impossible behaviour" - declaring that he was happiest "alone, sir, and with my back to the wall". Again, this is an image of the research leader that has stayed with us.

In case you think this is purely a British perspective, I recommend a look at Fritz Lang's epic 19 film Metropolis. The Inventor - the tortured genius Rotwang - embodies many quintessential components of the mad scientist, right down to the crazy hair, mad staring eyes, obsessive behaviours and a nasty habit of abducting attractive heroines. He even has an artificial hand - making him the spiritual forebear of our old friend Dr Strangelove, possibly Peter Sellers's most lasting creation.

Apart from such hugely overblown figures, however, memorable characters among the normal white-coated denizens of the laboratory are few and far between. One exception is Alec Guinness's subtle portrayal of textile scientist Sidney Stratton in the 1951 film The Man in the White Suit.

Stratton is a brilliant but hugely naive scientist who believes he has invented an everlasting, indestructible cloth, to the despair of bosses and workers alike. Naturally, the process involves large numbers of steaming - and clanking - retorts and assorted glassware. His character is such a thorough nerd that he even ignores offers of a suggestive nature from the daughter of a textile baron, played by co-star Joan Greenwood.

Guinness's character has essentially pure goals, but as the coverage of science in film developed further it spawned whole regiments of dodgy - almost Machiavellian - scientists, until today we are often left with distinctly two-dimensional characters playing out the same tired, and sometimes physically impossible, old storylines. Action films in particular, with their need for pace and their lack of room for either realistic science or character development, have given us some worthy contributions to the list of stereotypes.

É«ºÐÖ±²¥

Perhaps none of these is more memorable than Bill Murray's portrayal of Dr Peter Venkman, the famously sleazy parapsychologist in the 1984 film Ghostbusters. When Venkman is challenged on his intimately intrusive line of questioning he fells his antagonist with the immortal line "Back off, man, I'm a scientist", a line that has become a mirthful - but hugely indicative - mantra in some labs. This bombastic, self-obsessed model of the scientist gets dragged out repeatedly in the media - whether as an amusing stereotype or as a real attempt to portray an archetype.

É«ºÐÖ±²¥

If you move a few years further on, to Jurassic Park in 1993, you might cite Jeff Goldblum's rather racy mathematician Dr Malcolm as an attempt at a more rounded character. He at least makes a half-decent stab at explaining chaos theory to Laura Dern's blonde and rather giggly palaeobotanist. We should applaud this attempt to show communication between science specialisms, although it has to be said that his motives look a trifle prurient.

Are there any fictional scientists in the new millennium that might provide the public with an accurate picture of a science research practitioner? Only one character springs to mind from the recent crop of blockbusters: Professor Rapson of the Hedland Climate Research Center (sic), as portrayed by Ian Holm in the 2004 eco-epic The Day after Tomorrow. Whatever you think of the way the science itself is delivered, the figure of the British research institute director is carefully drawn: he is poorly resourced and keeps having to ask the Americans for help with, for example, computing power; he has only two staff - who appear to work 24 hours a day - and he exhibits no surprise when he wanders into the lab in the middle of the day to find them watching the football on TV.

Being British - of course - when the apocalypse comes he smiles, hands out glasses of whisky and then goes down with his ship. Not a bad end for an actor whose earlier incarnation as a scientist was in Alien, as the science officer of the space tug Nostromo - the company man responsible for ensuring that the Alien monster got into the spaceship to snack on the crew.

If realism in the portrayal of the subject is the key to the understanding of science, I'd say that we need more characters like that nice Professor Rapson. How are we going to achieve that? Well, a common trait in good science fiction - which shouldn't really surprise anyone - is that some of the most sympathetically drawn science characters, and those with the highest integrity, are those penned by scientists themselves. The late lamented Isaac Asimov and Arthur C. Clarke gave us some notable examples, and even Hollywood couldn't completely destroy the irredeemably stern character of Asimov's robo-psychologist Dr Susan Calvin in I, Robot. They couldn't make actress Bridget Moynahan look authentically plain, of course, but they did make her hair look a bit lank with just a suggestion of greasiness.

Does any of this really matter? Yes, I believe it does. As media consumers, we are immersed from an early age in a seething vat of influences that impact on the way that we view science. It is easy to laugh off the more tawdry aspects of film and television representations - but the pictures are still there in your head, as I hope I have demonstrated.

Today, more than ever, I think we need to see believable representations of science in the media. We need to see people whose research doesn't rely on strangely coloured - and oddly noisy - liquids in steaming retorts or on that unusually smart-looking machine that can analyse any known material in a nanosecond.

So here is a message for all you creative writing, film and television, drama and media studies lecturers out there: wander over to the next building on campus - it will be the knackered-looking one with the word "science" in the name - and go and talk to some real scientists. You may be surprised to find just how unstereotypical they are once you get to know them. When you have done so, feel free to point out some of the potential pitfalls of the genre to your students - and encourage them to look for the real characters, of which there are plenty. After all, despite all the stereotypes, scientists are only human: we just want to be loved.

John Gilbey has many years' experience as a lab rat and writes science fiction stories with as much integrity as he can muster.

É«ºÐÖ±²¥