About the size of it.

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You know that nanotechnology has arrived as a scientific force when cosmetics hype it, Michael Crichton writes a novel warning about it, Prince Charles castigates it, and demonstrators shed their clothes to protest it. Indeed, it must have been quite a scene at a nano-technology conference in Chicago when members of THONG (Topless Humans Organized for Natural Genetics) collectively dropped their pants to expose their rears festooned with the phrase "There's Plenty of Room at the Bottom."

The reference was to Nobel Prize winning physicist Richard Feynman's speech at the annual meeting of the American Physical Society in 1959, which many believe inspired the age of nanotechnology. Feynman mused about the possibilities of writing the entire contents of Encyclopaedia Britannica on the head of a pin, making tiny electrical circuits, and even manipulating single atoms. The latter would be the Holy Grail of chemistry. Today, chemists make new molecules by mixing together appropriate reagents, based on known chemical reactions. But imagine if a new molecule could be constructed by adding atoms one at a time, sort of like building with Lego[TM], except on a very small scale. A nanoscale! Pretty alluring. Except to protesters who suggest that such technology will also usher in problems--on a larger scale.

A nanometre is one billionth of a metre. That's pretty small. It would take 1,000 particles, each 100 nanometres in diameter, to span the width of a human hair. This is the scale we are referring to when we talk about nanotechnology--the field of science that deals with substances that have at least one dimension that is less than 100 nanometres. Why a separate area of study? Because on this scale, materials often behave very differently from their larger counterparts. Take a chunk of gold. You can toss it back and forth between your hands and admire its gilded lustre. Now, take that gold and make it into nanoparticles. Depending on particle size and shape, they show a range of colours from spectacular ruby red to a beautiful purple.

How do you reduce gold to nano levels? One method was discovered by Richard Smalley, Harold Kroto, and Robert Curl, Jr. who vaporized carbon with a laser in 1985, and ended up with a Nobel Prize for their efforts.

These researchers weren't really interested in nanotechnology. They had actually set out to investigate the chemistry of carbon-rich stars, but they made an amazing discovery. Vaporizing the carbon yielded particles that seemed to be made up of clusters of 60 carbon atoms. Smalley, playing with paper models, concluded that these clusters represented a novel form of pure carbon distinct from diamond and graphite, the two established forms of the element. He proposed that the 60 carbon atoms were linked together in the shape of a sphere, like a soccer ball. Eventually this novel arrangement of carbon atoms came to be known as "buckminster-fullerene" after architect Buckminster Fuller who had designed a number of geodesic domes. A more affectionate term for these C60 molecules was "buckyball." They really were "nano," being about one nanometre in diameter. Methods were soon devised to join carbon atoms so that they formed nanotubes instead of nanospheres, and the age of nanotechnology was ushered in.

Buckyballs and nanotubes turned out to have some unique properties not found in other forms of carbon. Buckyballs, for example, are effective antioxidants. They can neutralize those rogue species we hear so much about--the nasty free radicals that form as a byproduct of inhaling oxygen, and are linked with various diseases and aging. That's why buckyballs have been showing up in some cosmetic products, such as Zelens Fullerene C-60 Day Cream[TM]. But there is a question whether or not such a day cream might become a nightmare.

Some scientists, including Robert Curl, are concerned that the health effects of nanoparticles have not been sufficiently explored. Under certain conditions such as exposure to light, buckyballs can generate highly reactive "singlet oxygen," which can be damaging to tissues. It is also possible that harnessing the antioxidant potential of "fullerenes" can lead to some effective drugs. Experiments have already shown that grafting certain chemical groupings onto fullerenes makes them water soluble. In some animal models, it renders them effective against some free-radical-linked conditions such as Lou Gehrig's or Parkinson's disease. Fullerenes may become useful in ferrying medications into the body and delivering them precisely where they are needed. But that's the future. There is also nanotechnology now.

Remember the unsightly white stuff that protected many a lifeguard's nose from the sun's rays? Well, nano-dispersed zinc oxide--in which the particles are about 30 nm in size--offers superior protection and is totally transparent! Tennis balls coated on the inside with nano-clay platelets offer better air retention and more consistent bounce. Carbon nanotube reinforced composites make for stronger golf clubs and tennis racquets. Windows coated with nano-sized particles of titanium dioxide don't fog up and actually cause dirt to break down. And then there are the 10 nanometre long "nanowhiskers." These tiny fibres can be made to bond to fabrics and make them wrinkle- and dirt-resistant. But not activist resistant! In fact it was "nanopants," sold at a Chicago store that raised the ire of THONG and prompted another near-naked demonstration. This time the protesters anointed their anatomy with "Teflon is Toxic" signs, apparently believing that this material was the secret to the stain-resistant nanotechnology. Nonsense! Maybe the THONG-sters need to fill their nano-brains with some macro-science.

Popular science writer, Joe Schwarcz, MCIC, is the director of McGill University's Office for Science and Society. He hosts the Dr. Joe Show on Montreal's radio station CJAD and Toronto's CFRB. The broadcast is available on the Web at www.CJAD.com. You can contact him at joe.schwarcz@mcgill.ca.