The Ig Nobel awards are the supreme application of common sense to science: the common sense of humour. They will be announced in Cambridge, Massachusetts next week (October 2), rather than in Stockholm, Sweden, the week after, but they, in the footsteps of their rather more noble cousins, have become an eagerly awaited, keenly contested, globally reported event.

Real Nobel prizewinners turn up to hand out prizes, to be challenged to explain their work in 30 seconds, and to be booed off the stage. Real Ig Nobel prizewinners turn up at their own expense, proud to receive awards for some of the planet's most extraordinary observations.

Sometimes these candidate research papers are solemn, genuine, and touched by innocence. How else could you explain a psychology paper called "Farting as a response to unspeakable dread" or a meteorological study called "Chicken plucking as a measure of tornado wind speed" or public health research entitled "The transmission of gonorrhoea through an inflatable doll"?

Some research papers may simply be seen as shameless bids for an Ig, and were first published only in the journal Annals of Improbable Research, or AIR to its subscribers. One such was "The effects of peanut butter on the rotation of the Earth." It had several hundred authors but two lines of text: "As far as we can determine, peanut butter has no effect on the rotation of the Earth." Some represent a dramatic use of scientific or mathematical techniques to confirm things that no one had ever thought before of confirming.

This year, for instance, three geographers compared the flatness of Kansas to the flatness of a pancake. They used topographic data from a digital scale model prepared by the US Geological Survey, and they purchased a pancake from the International House of Pancakes. If perfect flatness were a value of 1.00, they reported, the calculated flatness of a pancake would be 0.957 "which is pretty flat, but far from perfectly flat". Kansas's flatness however turned out to be 0.997, which they said might be described, mathematically, as "damn flat".

The Igs are the brainchild of Marc Abrahams, citizen of Cambridge Massachusetts, and also editor of the Annals of Improbable Research, which comes out six times a year, rich in preposterous reports culled from 10,000 science journals. He began life at Harvard one year behind Bill Gates, and like Gates, he started a software company. He did not, however, end up rich. "I made the mistake of graduating," he says.

He also started writing things, never a great way to get rich. He took over editorship of an organ that had once been called the Journal of Irreproducible Results, and started asking serious scientists the dullest questions he could think of. "Is it better to use pencils or pens, and why? And then I just shut up. Sometimes you got a surprisingly interesting answer," he says. He launched a website with a difference called www.improbable.com, and found enthusiastic interaction: in a recent innovation, for instance, scientists nominate themselves or each other as members of the Luxuriant Flowing Hair Club.

He thought of the Ig awards in 1991, in the era of George Bush senior and his risible vice-president J Danforth Quayle, the man who once told the nation: "Quite frankly, teachers are the only profession that teach our - children." That year Abrahams awarded the late Edward Teller, father of the hydrogen bomb and the Star Wars initiative, the Ig Nobel peace prize for "his lifelong efforts to change the meaning of peace as we know it". He gave Quayle (who also said "If we do not succeed, we run the risk of failure") an award for demonstrating the need for a science education.

He booked a hall for 350 people for the ceremony, and waited for a disaster. It didn't happen. "In an afternoon, the 350 tickets vanished and on the night of the ceremony there were more people trying to get in, so we had people almost literally climbing the walls," he says. "We all had the feeling that at any moment some person in authority would walk in and tell us to stop and go home! But nobody did."

That first night, a British reporter came up to him and said: "This is so funny, this is so American, we have nothing like this in England." Two minutes later an American woman came up and said: "This is so wonderful, this is so funny, this is so British, we have nothing like this in America." He figured he had something people could not quite categorise, but it worked anyway. The Igs became an institution: graced by giants of science, including last year Sir David King, chief scientific adviser to the UK government.

Mostly he rings up his potential science winners, offering the prize and dropping the offer if they seem too alarmed. In 12 years, only a handful have demurred, worried about what their laboratory chiefs or research funders might say. The peace and economics laureates don't always get the choice: the first lot are usually politicians or police chiefs, the second class, including Nick Leeson, the trader who brought down Barings bank "usually have some kind of previous five to 15-year engagement".

The British have been consistently polite but also consistently inventive. The Royal Navy got the peace prize for economising on live cannon shells by telling sailors to shout "Bang!" when they opened fire in a mock engagement. A team at the Royal Gwent hospital in Newport, Wales, picked up a medicine prize for a paper in the Lancet headed "A man who pricked his finger and smelled putrid for five years."

In 1999, the Australian-born Len Fisher, of Bristol, turned up to share the physics prize with the Belgian-born Jean-Marc Vanden-Broeck of the University of East Anglia. The first had devised a mathematical equation for dunking a gingernut in a cup of tea, the second a teapot spout which did not drip. Moments after Dr Fisher received his award, a huge artificial doughnut descended from a rope and pulley over the heads of the audience and, says Abrahams, "dunked itself into an attractive, leggy, tapdancing teacup".

The research behind some awards - for example, "Rectal foreign bodies: case reports and a comprehensive review of the world's literature" - is too excruciating to discuss in detail, but collectors might like to know that it lists 11 kinds of fruit, vegetable and other foodstuffs as well as a beer glass and a frozen pig's tail. Some awards - such as the one to the Apostrophe Protection Society of Boston, England - clearly promote good causes and better grammar.

Many researchers nominate themselves. One University of Bergen team in 1996 sent in their British Medical Journal paper headed "The effect of ale, garlic and soured cream on the appetite of leeches" and accompanied it with a note explaining why they should be outright winners. For once, they were. The prize was accepted on their behalf by Norway's honorary consul to Massachusetts, who said: "I do fear this topic is not taken seriously here in Cambridge," and threw a bag full of plastic leeches into the audience.

· To order a copy of Ig Nobel Prizes, by Marc Abrahams (Orion), for £6.99 with free UK p&p, call the Guardian book service on 0870 066 7979. Published by Orion.