against the odds

We looked first at eccentric scientists and inventors, in and outside of academia. Eccentric inventors exemplify a need to find out more about the world, a motivation driven by their intrinsic curiosity in its purest form. Many of them have succeeded in developing quite useful devices, while others have devoted their lives to inventing absurd, fantastical contraptions. I interviewed about a half dozen completely sane eccentrics who were bent upon unravelling the mysteries of perpetual motion, the inventor's equivalent of the elixir of life.

Since even before the Industrial Revolution, the notion of the perpetual motion machine (or fuelless engine, as it is sometimes called) has captured the imagination of thousands of inventors, entrepreneurs and assorted get-rich-quick merchants, despite incontrovertible scientific evidence that it is impossible. The very notion, in practice, violates several of the known laws of thermodynamics; that of the conservation of energy and another which states that part of the energy of a continuous process is always lost as heat. In any case, nothing in the world is perpetual: rust, friction, obsolescence and general wear-and-tear put a limit on the life of almost every known mechanical device. It is the way of all flesh, or as Professor Eddington once dubbed it, ''Time's Arrow''.

Confronted with these laws of physics, the eccentric inventor is undaunted, thriving on the conviction that even if they approach near to perpetual motion, without attaining it ''all the way'', valuable lessons and benefits will be gained. Eccentric scientists, including those who know of these laws, treat them derisively and defiantly, as challenges rather than as inevitable limitations. Their tenacious denial in the teeth of overwhelming contrary evidence dwarfs perseverance of even Churchillian proportions. They theorise and act as if 100% of all potential energy equals 100% of accessible energy for use, if only the right techniques could be found and implemented correctly.

It is also clear that ''impossible'' is not a word in any eccentric's vocabulary. Yvonne X (that is her real name, obtained by deed poll) builds perpetual motion and floating levitation machinery in her home laboratory in Westfield, New Jersey. As it happens, she lives on the same street as the cartoonist who first penned the Addams Family into being. When I paid a visit on her in 1992, she told me that she had always been an inventor: ''When I was a kid, I got so interested in the race to the moon that I started making my own rockets. There was no method to my early experiments - I just got a big kick out of the explosions. I loved to see my rockets go up. Then my concern about the environment led me to try to invent energy traps like this one here.''

She led me into her workshop in a dank cellar and proudly pointed out the latest model of her machine, which looked like a combination of a row of milking machines and something out of a low-budget 1950s science-fiction film. Gleaming stainless-steel cylinders were mounted on a frame along the brick wall. Tubes sprouted from the tops and bottoms, joined together by candelabra-shaped connectors. In the far corner more tubes dripped from the ceiling like plastic spaghetti. In the exact centre was a highly-polished, silvery disk, about the size of a flattened rugby football, mounted on a tripod and suspended by thin wires.

When Yvonne switched the machine on, the tubes began twitching as a frothy liquid coursed through them. While the machine was warming up, its inventor expounded its ''scientific'' principles to me: ''This system produces energy without any combustion and preserves it safely. The flux of these liquids here can be made to create kinetic energy, which can then be changed, hey bingo, into cheap electricity. When the disk ascends off its launch pad, we will have excess power to spare!''

With a flair for evincing not the slightest touch of trepidation, she squeezed a little red trigger to activate the disk. The pipes and tubes began vibrating violently. A deep rumble issued sickeningly from the cylinders, and a gasket blew off one like a bullet, splattering test tubes to left and right. Then the silver disk, spinning with a gentle hum, began to ascend, faster and faster, until it finally crashed right through the workshop ceiling, and two other floors and ceilings, exiting through the roof like a flare. I could see the the full moon shining through the holes it left behind. There was a second or two of calm. Yvonne X and I gaped at one another.

Then, as John Milton said, all hell broke loose. Behind us a beaker exploded, then another. Sparks came showering out of melting wires. The room was filled with the acrid smells of raw electricity and singed beard and eyebrows (mine). The sprinkler system, somewhat belatedly, tripped on and sprayed the room with cold water. Yvonne turned and unceremoniously headed for the stairs, with me treading on her heels and feeling very much like a character in a particularly violent Hollywood cartoon. The Fire Department was soon on the scene. As the firemen shook their heads and hosed down the scene, Yvonne X, undaunted, was already in her imagination going back to the drawing board, brainstorming a solution for this latest little hiccup. She confided to me she was certain she knew what was wrong with the design, and vowed to start over, never to swerve off her path of true discovery.

That incorrigibly indomitable spirit of hopefulness is almost universal among eccentrics. And men and women of genius.

l Dr David Weeks is a clinical neuropsychologist based in Edinburgh