Luckily the literature is not like a barrel of apples and one bad paper will not ruin all of the others. There are also different types of mistakes with different consequences. Deliberate mistakes are the most damaging and, on the basis of recent high-profile cases, such scientific fraud is largely a problem for life scientists rather than physical scientists. One reason for this is that the concept of reproducibility is less clear-cut in biology, although financial considerations also play a role.

Most mistakes, however, will be honest ones. If an honest mistake has major consequences then it will be spotted quickly and little harm will be done. If the paper is of little consequence, the evolutionary processes at work inside science mean that the paper will effectively die. The biggest problem with honest mistakes is that a lot of time and money can be wasted by other researchers. We can take comfort, therefore, from recent developments in the search for both extrasolar planets and life on Mars.

The planet story has turned full circle. In 1995 two Swiss astronomers published evidence that a planet with half the mass of Jupiter was orbiting close to the star Pegasi 51. Many astronomers were puzzled as to how such a large planet could have formed so close to a star, but the finding was accepted by the community and was quickly followed by several other discoveries. Last year, however, a Canadian astronomer published a high-profile paper suggesting that Pegasi 51 did not have a planet. Now the same astronomer has looked at the data more carefully and changed his mind, concluding that a planet may be the best explanation after all.

The life-on-Mars story is not so clear. Moreover, it involves researchers from a range of disciplines including biology, geology, chemistry and space science. In 1996 US researchers reported evidence for microfossils in a meteorite that originally came from Mars. Now one team of US researchers is claiming that the microfossils are geological, not organic, while two other teams claim that the organic material in the meteorite came from the Earth in the first place.

What both cases show, however, is that when the stakes are high, scientists will attempt to reproduce results, and mistakes of all types will be weeded out.

Physics and biology

There has been a lot of loose talk lately about the next century being the century of biology. This has come to a head with reports that the US president, Bill Clinton, has said that biology will be the science of the 21st century just as physics was the science of the 20th century. As with much of what Clinton says, or is reported to say, the true story is often distorted. For the record, what Clinton actually said was: “I do believe that in scientific terms, the last 50 years will be seen as an age of physics and an age of space exploration. I think that the next 50 years will very likely be characterized predominantly as an age of biology and the exploration of the human organism.” Comforting words for life scientists, to be sure, but hardly the end of physics at we know it.

This magazine has often advocated that physics and physicists should see medicine and biology as an opportunity rather than a threat. These opportunities range from the most basic researches into the workings of cells and the brain to the development of sophisticated hardware for the diagnosis and treatment of disease (June 1996, July 1997). The movement of physicists into these fields is not an admission of defeat but a natural and logical application of physics. And if it resonates with politicians and funding agencies, so much the better.