Very small, and maybe not so threatening after all

Some scientists blame it all on the film Fantastic Voyage. In the 1960s, and for a generation afterwards, the fantastical idea of miniaturising a group of people and injecting them into a human body became ingrained in the public's consciousness. It could not be done, of course. But now nanotechnology, the science of molecular-sized machines and systems, seems to promise something like it.

Some scientists blame it all on the film Fantastic Voyage. In the 1960s, and for a generation afterwards, the fantastical idea of miniaturising a group of people and injecting them into a human body became ingrained in the public's consciousness. It could not be done, of course. But now nanotechnology, the science of molecular-sized machines and systems, seems to promise something like it.

The Royal Society will today produce a report intended to encourage a debate about this exciting new departure and debunk some of the myths. Great potential benefits to humankind could emerge from this research. Some scientists believe microscopic robots could be injected into a person's blood to monitor cholesterol and even seek and snuff out cancers.

The trouble is that the peddlers of horror stories have had a head start. The novelist Michael Crichton has written a sci-fi thriller about malevolent "nanobots" which consume all material, living and dead, and reproduce themselves indefinitely. Similarly, our very own Prince of Wales has voiced his fears about all life being reduced to "grey goo" by such machines. Of course, such tall stories have been consistently rubbished by scientists over the years. And some might be tempted to conclude that if Prince Charles is against something, there must be some merit in it.

There is, nevertheless, a serious danger, that if the public is exposed only to misleading scare stories, nanotechnology could share the fate of genetically modified crops and be seen as something foisted on an unwilling public by arrogant scientists. This would be a loss, not least because we are already enjoying some of its benefits. Beauty products and sunscreens contain nanoparticles that enable them to penetrate and protect the skin. Tennis balls and trousers use them to keep air in and stains off.

Today's Royal Society report should help broaden the debate. But what nanotechnology really needs is to make itself better known. Perhaps products that already make use of it could feature a "nano-label". After all, it would not have to be very big.