Eureka!

Sometimes, scientists perform experiments that sound simply ridiculous - and then turn out to revolutionise our view of the world. But for each such pioneering investigation, there are hundreds of others that really are harebrained or misconceived. Len Fisher sorts out the visionaries from the cranks

Weighing the soul

Weighing the soul

Philosophers have long argued over whether the soul, if it exists, is a material substance or not.

In the early 1900s, the America doctor Duncan MacDougall decided to try to find out by putting patients dying from tuberculosis - bed and all - on a set of scales and watching to see whether their weight dropped suddenly when they died. Staggeringly, it did, in four out of the six patients that he studied, with an average weight change of 21 grams - about as much as a slice of bread.

Were MacDougall's experiments brilliant or bizarre? If one accepts his argument that the soul must be a material substance in order to be able to affect our material bodies, then the experiment was a sensible one, and certainly fits modern scientific criteria. One of those criteria, though, is that "extraordinary claims require extraordinary proof", and the limited sensitivity of MacDougall's scales has left his results open to doubt.

It would be very interesting to repeat his experiments using accurate, modern scales - any volunteers?

Computers from water

When I began working as a scientist in the late 1960s, the big news was that molecules that were dissolved in water could affect the structure of the water over quite long distances.

The claim seemed incredible, but experiments proved it to be true. Then, in 1988, the French immunologist Jacques Benveniste (who died this year) claimed that the water "remembered" the imposed structure even after the added molecules had been diluted out. If Benveniste's claim had been true, we could make computer memories out of water, and water that had contained "homeopathic" molecules would retain its supposed abilities to cure.

His claim went against established science, where there is an accumulation of evidence which shows that water structure is labile and evanescent on a time-scale of microseconds. It may have been a brilliant and unexpected new phenomenon, but scientists have been unable to replicate his experiments, and his "discovery", like so many others, has been relegated to the ranks of the bizarre.

Levitating frogs

My colleague at Bristol University, the renowned theoretical physicist Sir Michael Berry, made headlines several years ago (and earned an Ig Nobel Prize) through his studies with Dutch professor Andrey Geim on how to levitate a frog. Was this just physicists having fun, or was there a more serious purpose?

In fact, the purpose was very serious. For more than 150 years, physicists have believed it is impossible to balance gravitational and magnetic forces to achieve stable levitation, no matter how the magnets are arranged.

There is even a theorem (Earnshaw's theorem) that proves this. Berry was the first person to spot that the theorem does not apply if the object is spinning, as does the magnetised metal frog in a toy known as a levitron. Not content with toy frogs, he arranged with Geim to experiment on a live frog which was "magnetised" by suspending it above a powerful electromagnet. The pictures of the surprised, but otherwise unharmed, frog slowly spinning in mid-air are among science's most memorable icons.

Dangers of farting cows

Anything that a scientist can calculate, he or she will. Einstein calculated in his youth that putting his socks on in the morning and taking them off again at night would occupy him some hundreds of hours during the course of his life, and thereafter went sockless.

More recently, scientists turned their attention to calculating the amount of methane that cows produce as they burp and fart their way through the day. It sounds like the meaningless calculation of an idle moment, but they found to their surprise that enough methane - second only to carbon dioxide in the list of greenhouse gases - was being produced to contribute to global warming.

The problem is so serious that Australian scientists are now using the techniques of genetic engineering in an attempt to reduce the problem.

Capturing lightning

In 1752, the Frenchman Thomas-Francois D'Alibard devised an experiment to collect lightning and put it in a bottle.

He had a dragoon called Coiffier stand during a storm on a stool that consisted of a slab of wood supported on three empty wine bottles while holding a 15-metre-long iron rod; the lower end touching a bottle covered, inside and outside, with metal foil (a Leyden jar).

This sounds crazier than self-trepanation, but it worked (and Coiffier survived) and provided the first proof of Benjamin Franklin's conjecture that lightning was a form of electricity.

Self-trepanation

If you have a sensitive disposition, you would be wise to skip straight to the next topic. Trepanation (cutting a hole in the skull to relieve pressure) was practised by the ancient Egyptians. In the 1960s, Joey Mellen and Amanda Feilding decided to try it in the hope that it would "expand their consciousness". Unable to find any doctors willing to perform the operation, they each did it on themselves - looking in a mirror while using an electric drill fitted with a cylindrical saw blade. Amazingly, neither died, and both claimed an enhanced feeling of well-being after the experience, so that in their own eyes at least the experiments were a success.

They later married each other and seem to have lived a normal family life. Amanda made a film of her self-operation (called Heartbeat in the Brain), which still has the power to cause viewers to faint.

The Brazil-nut effect

Looking for a daft-sounding experiment? Then you need go no further than those performed by food scientists in the 1970s in an attempt to resolve the vexed question of why Brazil nuts always seem to come to the top in a packet of muesli or mixed nuts. Surely this was a waste of time?

Wrong again. Mixing problems of this type are very important in many industrial applications. Uniform mixing is especially important when it comes to drug production - I wouldn't be too happy if some of the pills I take to control my blood pressure contained double the specified dose of drug particles, while others contained none. On the flip side, the Brazil nut effect can be used to separate out larger from smaller grains of rice, say.

The effect happens when smaller objects fall into the voids below the larger ones as the mixture is shaken, so that the larger ones are pushed inexorably upwards, contrary to intuition. (Before my fellow scientists start taking pot-shots at me, I am fully aware there are other processes at work.)

Feeding Prozac to clams

This experiment seems too fatuous to be true and earned its perpetrator, Professor Peter Fong of Gettysburg College, Pennsylvania, a spoof Ig Nobel Prize in 1998. The motto of the prize is: "First, they make you laugh. Then, they make you think."

I found that Fong had done a good deal of thinking and that his odd-sounding experiment was far from fatuous. One of the problems that commercial clam farmers face is that of inducing the clams to spawn in synchrony to maximise the number of baby clams produced. To start the process, US clam farmers use very expensive chemicals. Fong noticed that Prozac - a much cheaper material - had a similar chemical structure. Thanks to Fong, clam farmers in the Third World can compete on a more equal basis with US counterparts.

Viagra on wilting flowers

Finally, and briefly, there was the scientist who tried the effect of adding Viagra to a vase of wilting flowers.

Viagra works by maintaining the blood pressure in the penis at a high level, but plants don't have a blood supply, so the experiment seemed pointless. But it worked and the flowers stood upright - for up to seven days beyond their normal life span.

The message is that anything is worth a try. A second message is that, although failure is much more common than success, we need to allow for many failures if we are to have those few brilliant successes. It is a message that governments and their funding bodies would do well to heed.

Len Fisher is Honorary Research Fellow in the Department of Physics, University of Bristol. His 'Weighing the Soul: The Evolution of Scientific Beliefs' is published by Weidenfeld & Nicolson, £12.99. He will be speaking at the Science Museum's Dana Centre, London SW7, tomorrow from 7pm. (Events are free but must be pre-booked on 020-7942 4040 or tickets@danacentre.org.uk)