Funny thing, though: once you break one, it’s hard to think about anything else.

When first I wrote about bones, back in a 1993 instalment of this column, I told the story of my own broken-bone experience, for which I blame my big brother, Dwight (mainly because it was his fault).

I was seven years old and he was 12. We were both inside a big cardboard box that had held a refrigerator. For some reason, we’d decided it was fun to roll down the back steps inside this box. And it was fun, right up until Dwight’s friend from down the street jumped on top of the box. Inside, my brother was on top of my arm, which was up against the steps, and I was suddenly the startled owner of an L-shaped wrist.

My indignant initial reaction (I tried to say, “Now look what you’ve done,” but it came out more like “Glubbleulp!”) gave way to an intensely personal curiosity about bones. “Someday,” I vowed, “I will write science columns about them!”

This particular vow-fulfillment column was prompted by the report of a new procedure to turn blocks of wood, of all things, into artificial bones.

Developed by scientists at the Instituto di Scienza e Technologia dei Materiali Ceramici in Faenza, near Bologna, Italy, the wood-derived bone substitute promises to allow live bones to heal faster and more securely after a break than the metal and ceramic implants that are currently used.

It makes sense, because if you’ve ever seen a cross-section of a bone—there’s one at the Saskatchewan Science Centre, if you’d like to run down and have a look—you will have noticed that, far from being solid, it’s quite porous.

As I noted in that original column all those years ago, “We think of bones as hard, dead matter, like hair or fingernails, but they’re actually organs consisting of living cells embedded in a matrix of calcium phosphate and other calcium minerals, held together by collagen, the tough fibrous protein we also use to make ligaments, tendons and skin. Bone tissue constantly renews itself…dissolving old tissue and…depositing new tissue.”

That’s why broken bones can heal themselves. But when titanium is used as a bone implant, bone can’t interact with it. Instead, the titanium is simply encapsulated in fibrous tissue. Nor is it practical to introduce pores into the titanium: that weakens it to the point where it could break, inflicting more damage.

Wood, however, like bone, is porous. Bone tissue can interact with the new wood-based substitute bone, growing right into it, along with blood vessels, nerves and more.

Titanium and ceramic implants can also damage bone simply because they’re so much harder than it. Whereas natural bone flexes slightly (and that stress actually strengthens the bone), the harder, less flexible implants can apply so much stress to a particular area that the bone snaps.

So how do you go about turning wood into something approximating bone?

The process begins with a block of wood (rattan works best). It’s heated until nothing remains of it but pure carbon (i.e., charcoal). The charcoal is then sprayed with calcium, which creates calcium carbide, then heated further under intense pressure and treated with a phosphate solution. After about 10 days, the wood has become a bone-like material.

The cost? About $850 per block, which provides enough material, on average, for one bone implant. Virtually any size or shape can be created.

Dr. Anna Tampiere, leader of the research team, says the new material is strong enough to take the heavy loads bodies place on it, and durable enough that, unlike existing bone substitutes, it will never need replacing.

The bone substitute has been implanted into a flock of sheep. X-rays show that, indeed, the sheep’s bones have migrated into the wood substitute. With time, says Tampiere, “you don’t even see the join.”

Human tests are probably still about five years away, but so far there has been no sign of the sheep’s bodies rejecting the new material, raising hope that this new process could give us a natural, cheap and effective replacement for bones.

Bonus: these implants won’t set off metal detectors at airports.

It sounds even more like a 2 a.m. infomercial product when you see headlines about it that claim it is “about to revolutionize everything.”

Maybe it’d sound more impressive if I used its more formal name, which is “SiO2 ultra-thin layering,” but that’s hard to type, so I’m going to stick with “spray-on liquid glass.”

Besides, that’s exactly what it is: an extremely thin layer of glass that can be sprayed onto…well, just about anything.

Though it was invented in Turkey, the patent for spray-on liquid glass is held by the German company Nanopool.

It consists of almost pure silicon dioxide, a.k.a. silica, extracted from quartz sand. Water or ethanol is added, depending on what kind of surface is to be coated: the water-based versions are good for absorbent surfaces such as stone, wood and fabrics, while the ethanol-based versions are suitable for metal, glass, plastic and painted surfaces. There are no other additives: a bottle of liquid glass contains only water or ethanol, and molecules of silica. And not too surprisingly (since silica is the most abundant mineral in the Earth’s crust), the coating is non-toxic and environmentally harmless.

The glass binds to the surface through quantum forces that come into play at the extremely small scale of these tiny glass particles. The coating is only about 100 nanometers thick–that’s only 1/500th the width of a human hair.

An article in the June, 2009, issue of the U.K. magazine Cleanroom Technology has a pretty complete list of the coating’s benefits.

First of all, it’s flexible, meaning it can be used to coat, not just hard surfaces like countertops and sinks, but fabric, conveyor belts, medical devices such as endoscopes, and more.

It’s highly durable, able to withstand tens of thousands of cleaning cycles, and heat tolerant, unaffected by temperatures as low as -150 C and as high as 450 C. It also resists both acid and alkaline substances.

It doesn’t kill bacteria, but it also doesn’t provide them with a friendly surface to attach themselves to and multiply. Wash a coated surface with hot water, and the bacteria are wiped away more effectively than you can achieve with bleach on an uncoated surface (as tests in an Austrian cheese-packaging plant have proven).

It’s so thin that it’s invisible to the human eye and can’t be felt; while it’s slippery at the micro level, at the macro level (our level), it isn’t. In fact, since bacteria can be so easily cleaned off of it, a coated shower floor would probably be less slippery, because of the lack of bacteria-produced biofilms.

The stuff is easy to apply: even large areas such as floors, walls and windows can be coated with it in minutes, and no special equipment is needed. And finally (and even more amazingly), it’s cheap: the cost to cover a square metre ranges from about 40 cents to $1.80.

Sounds too good to be true, doesn’t it? Surely it must be full of little tiny glass particles that are going to get into our lungs and cause asbestos-fibre like problems?

Nope. The coating contains no discrete or potentially harmful engineered nanoparticles.

Spray-on liquid glass is already available in Germany for domestic use, for about $8.50 a bottle. In the home, it could conceivably make existing cleaning products obsolete, since hot water would do the job chemicals are doing now. It could be used in the oven, bathrooms, tiles, sinks, and on almost any other surface, and the coating is expected to last about a year with normal use.

Outside, the uses are endless. A silk shirt coated with it would shrug off a spilled glass of red wine. Stone coated with it could be more easily cleaned of graffiti. Seeds sprayed with it are protected from fungal and bacterial attacks and germinate and grow faster than untreated seeds. Wood treated with it has survived undamaged after being buried in a termite mound for nine months.

A Lancashire hospital has had “very promising” results using it as a coating for everything from equipment to medical implants, catheters, sutures and bandages.

It sounds amazing.

But it also still sounds like a 2 a.m. infomercial product.

I guess time will tell.

Clothing is about to be revolutionized by a slough of new technologies.

Imagine, for example, fabric that can change pattern or colour on demand. International Fashion Machines, a small company in Cambridge, Massachusetts, has developed Electric Plaid, which can do just that.

Currently on display as part of the National Design Triennial at New York’s Cooper Hewitt National Design Museum, Electric Plaid looks like a multicoloured, hand-woven textile–but a circuit board attached to the back can be programmed to send current through conductive fibers woven into the textile, heating them up. Temperature-sensitive inks used in the textile change colour as a result, altering the wall-hanging’s pattern.

Another way to create a colour-changing fabric has been developed by researchers at the Massachusetts Institute of Technology. By combining thin layers of a plastic and glass, they’ve produced a new fiber that reflects all the light that hits it, from any direction. Cloth made from the fiber normally has the rainbow sheen of an oil slick on a rain puddle, but altering the thickness of the fibers, which could be accomplished by sending current through them, would change the wavelength of light they reflect, and thus the colour.

Colour-changing clothing would have obvious camouflage benefits for the military, but the ultimate camouflage would be an invisibility cloak–and you don’t have to be Harry Potter to have one any more. Last spring Susumu Tachi, a university professor at the University of Tokyo, demonstrated one. His shiny raincoat was really a kind of movie screen, which showed the image from a video camera on his back–an image of what the viewer would see if he wasn’t standing there.

Tachi’s invisibility cloak was crude, but it demonstrated that something very much like invisibility is technically possible. In the current issue of Wired Magazine, Wil McCarthy calculates what would be required to make a really effective invisibility cloak: it would have to have six stereoscopic camera pairs built into it, be covered with 11.6 million “hyperpixels,” each consisting of a very bright 180 X 180 LED array behind a hemispherical lens, and be controlled by a computer running at 10 billion or more gigahertz while drawing little enough power that the power source can be built into the cloak…in other words, don’t hold your breath. Something more like Tachi’s device, however, could still be useful for stationary objects.

If you can’t get an invisibility cloak, you can at least get a bullet-proof shirt–if you can afford it. A research team at the NanoTech Institute at the University of Texas in Dallas has come up with the toughest lightweight fiber ever developed–four times tougher than spider silk, and 17 times tougher than Kevlar, which is what current bullet-proof vests are made out of.

The secret is carbon nanotubes, tiny rolled-up sheets of carbon atoms found naturally in soot. The research team combined the nanotubes with water and a plastic to form a gel, which the researchers then spun into long, continuous fibers, easy to weave and sew. Unfortunately, carbon nanotubes currently cost $15,000 U.S. an ounce.

More readily available soon may be coats that put out extra heat–and even a little light. Lucy Dunne, a Cornell Unversity graduate student, has developed just such a jacket. Her “smart jacket” automatically heats up (by sending current through conductive fibers in the upper back) when sensors tell it it’s getting chilly, and automatically lights up (by sending current through electro-luminescent wires around the neck and bottom of the jacket) when sensors tell it it’s getting dark. The left wrist cuff contains a pulse-rate monitor, for joggers and hypochondriacs.

That kind of practical jacket is likely to be on the market soon. Other “super-clothes” have already made it: socks that prevent smelly feet by inhibiting bacteria growth; snow suits embedded with GPS systems, heating systems and emergency alarms; clothing that can wick away liquid spills without staining; even aromatherapy business suits.

All new technologies have unintended side-effects, though. I foresee a huge increase in tardiness as people who can barely make it to work on time now are overwhelmed by their new clothing choices.

Fortunately, one new product is a shirt with an integrated cell phone. You’ll be able to use it to phone your boss and tell him you’ll be late.

It’s a little startling to find out, then, that something instinctively understood by children–that damp sand sticks together–was only recently explained scientifically in 1997. Dr. Peter Schaffer, an assistant professor of physics at Notre Dame University, was trying to assemble a swing set for his two-year-old. The swing’s plastic pieces had to be weighted down with sand, and Schaffer noted that dry sand sifted easily through the tiny opening provided, but damp sand clumped around it. He wondered why–and decided to find out.

Schaffer and colleague Dr. Albert Laszio Barabasi, with the help of a few grad students, mixed polystyrene spheres, each 0.8 millimetre in diameter, with a tiny amount corn oil and vacuum pump oil, put the mixture into a container with a plugged hole in the bottom, then pulled the plug. The spheres drained out and formed a cone; the researchers then measured the angle of the cone’s sloping sides.

They found that as they gradually added more oil, the cone formed steeper and steeper sides–until, suddenly, the spheres started clumping together. What bound the spheres together–and makes wet sand good for building sandcastles–the researchers figured out, was tiny bridges of liquid.

Fluids prefer to assume the shape that has the lowest potential energy. The larger the surface, the more energy there is, so fluids resist having their surface area increased–the molecules at the surface of the liquid cling tightly to each other, making the surface act like a membrane. The oil formed bridges between the spheres because that formation has the lowest potential energy. Of course, add too much liquid and surface tension disappears because there is no air between the particles to create a surface to the liquid–and your sand castle washes away.

Sand is a bit more complicated–it’s not made up of perfect spheres, but of millions of tiny sharp-edged particles. Sand under pressure–buried deep underground, for instance–will hold together due to friction between particles and interlocking between the particles’ faces, no matter whether it is dry or wet.

But a layer of wet sand deep underground sometimes exhibits a property that puzzles researchers. In the Marina District of San Francisco during the 1989 Loma Prieta earthquake, a layer of wet sand underground, usually solid because of the immense pressure of the layers of rock and soil above it, liquefied in response to the earthquake’s vibrations, to the point that many buildings sank until their third floors were at ground level.

Exactly what caused this is poorly understood. Scientists do know that during an earthquake, shockwaves compress the soil faster than water can escape. This raises the pressure of the water, causing it to bear more and more of the load and the sand less and less. The result is a reduction of pressure between individual sand grains; eventually the friction holding them together vanishes and the sand liquifies. But it’s very difficult for researchers to find out exactly how those grains of sand interact with each other as the pressure between them approaches zero, because the sand itself has weight, which creates stress.

The solution is to send the sand into space, where gravity can’t interfere with observations. Two shuttle flights have already carried an experiment that examines what happens to dry sand when compressed in a fashion similar to that of an earthquake. (It revealed, among other things, that a layer of dry sand at low pressure can support twice as much weight as previously thought.) In an upcoming mission, the experiment will be repeated with wet sand. A column of water-saturated sand in a latex sleeve will be squeezed over and over between two plates. Each squeeze-and-release cycle will take about 10 minutes. Cameras will document how the column of sand deforms. Once the column is back on Earth, scientists will use CT scans to study its internal structure, then inject epoxy into it so it can be sliced and studied in further detail under the microscope.

Understanding the physics of sand is important not only because of the danger of soil liquefaction during earthquakes but because humans use so many granular materials besides sand, including grain, bulk cereals, coal, ash and many fertilizers. Knowing how to convince any of these materials to either stay in place or flow smoothly could lead to safer and more efficient ways of handling them.

It might even lead to better sandcastles.

It’s called smart fabric, because it turns fabric into a sensitive computer interface.

The underlying technology, called Kinotex, was developed by the CSA to enhance the dexterity of the robot arm and to provide it with a sense of touch, so that it could tell when it made contact with something and stop its motion before any damage occurred. The technology also had to be robust enough to use in outer space.

Smart fabric consists of network of fiber optic threads, each thinner than a human hair, sandwiched between foam layers. Each depression in the foam alters the light stream running through those threads in a different way. You can press the foam, dig your fingers into it, even grab it and twist it, and a computer can interpret the resulting signals with great sensitivity. By assigning functions to the various permutations, you can use the smart fabric to run, via computer, pretty much anything you want.

Many laptop computers already use a touch pad in place of a mouse–you can control your pointer just by running your finger over the pad. The new technology, however, allows the computer to interpret the touch not just of one finger, but of all of them, and to react not just to their placement, but how hard you’re pressing them down, how they’re curved, and more.

The new smart fabric control interfaces can also be any size, large or small; flat, curved, or flexible; and covered in a variety of materials from leather to metal foil without affecting performance.

Bringing smart fabric down to Earth is the goal of a company called Canpolar East, which has the exclusive license to the CSA patent. Among its subsidiary companies is one in Victoria called Tactex, which has already created a computer touchpad, the MTC Express (which costs $495 U.S.) that uses smart fabric.

The MTC Express won the Most Innovative Product of the Year award at the National Association of Music Merchants show in Anaheim, California, last month. That’s because the touchpad promises to give musicians a whole new way to interact with electronic devices.

For instance, a California company, Midiman, has turned the touchpad, which is only a few centimetres across, into a mixing board for musicians called Surface One. The touchpad is so sensitive and programmable that it can control all the tracks and the program fade ins and outs, activate special audio effects, control a light board at a performance and act as a synthesizer, all at once. Musicians such as Beck and technical people such as the sound engineer for David Lynch’s films have already expressed interest in Surface One, which lets them control effect with their fingertips, just like playing a guitar.

Probably the next use for smart fabric will be in videogame controllers that let players control characters with much more intuitive gestures than joysticks or gamepads allow.

But that’s just the beginning. Fabric that can communicate with a computer opens up a fascinating range of possibilities. Imagine, for example, clothes that change color or play music when touched or moved in a certain fashion. Think what fashion designer could do with the former, and dancers with the latter.

Think of what artists could do with smart fabric. They could draw and paint electronically with their fingers; even create virtual 3-D sculptures, working smart fabric as though they were working clay.

Imagine a couch that turns on the TV automatically when you sit in it–and lets you change the channel simply by tracing the channel number you want on the couch’s arm. Or think of a car seat that knows which member of the family is sitting in it by the shape of that person’s, um, anatomy, and adjusts itself–and the height at which the airbag is set to deploy–accordingly.

How about a mattress that detects your restless tossing at night and plays soothing environmental sounds or music until you settle down, or a carpet that knows who is entering a room by the characteristics of the feet it “feels” and adjusts room lighting and temperature according to preset commands–or turns on the radio or TV.

As Tactex puts it, smart fabric control surfaces give humans a new way to control “their computers, instruments, toys and tools.”

It’s amazing stuff–and best of all, it’s Canadian.

Teflon was discovered by accident by Roy J. Plunkett, 27, a DuPont scientist who was trying to develop a new chlorofluorocarbon (CFC) for use as a refrigerant by reacting a gas called tetrafluoroethylene (TFE) with hydrochloric acid. He’d prepared 100 pounds of TFE in pressure cylinders, which, for safety reasons, he stored in dry ice.

On the morning of April 6, 1938, Plunkett’s assistant, Jack Rebok, opened the valve of a canister of TFE–and nothing came out. They weighed the cylinder. The gas was still inside, but it wouldn’t come out.

Plunkett, frustrated, took off the valve, turned the canister upside-down, and shook it. Some flecks of white powder floated out. Intrigued, Plunkett and Rebok sawed open the canister and found a smooth, waxy white coating lining it. The substance wouldn’t char or melt and seemed to be impervious to solvents, moisture, sunlight and mold and fungus.

Apparently the cold and pressure had caused the molecules of TFE to join together in long chains, or polymerize, so Plunkett dubbed the new stuff polymerized tetrafluoroethylene (PTFE), and patented it for the company in 1941.

DuPont continued experimenting with PTFE, trying to figure out how to produce it commercially. The Second World War provided a boost: PTFE was used in the nose cones of proximity bombs and in airplane engines, even though it cost $100 a pound. In 1944, DuPont trademarked PTFE as Teflon.

It wasn’t easy to produce. Early batches tended to have widely differing properties, and making it required equipment to withstand higher temperatures and pressures than ever before. Turning it into useful articles was problematic, too. Its melting point was so high it couldn’t be molded or extruded, and as for bonding it to something else–how do you bond the greatest non-stick surface every created?

Fortunately, researchers found several ways. In granular form, Teflon could be compressed into blocks that could be machined; it could blended with hydrocarbons and cold-compressed to coat wires and make tubing; or it could be blended with liquid and turned into enamels that could be sprayed or brushed, then baked into place.

The first commercial Teflon plant opened in 1950. Most of the output went to commercial applications: tape, sheets of insulation, gaskets, valves, etc. Bread manufacturers used Teflon-coated rollers; candy factories used Teflon-coated conveyer belts.

The first Teflon-coated baking pans appeared in the 1950s. Concerned about safety, DuPont proceeded very slowly with the development of Teflon-coated pans for stovetop use; meanwhile, in France, an engineer named Marc Gregoire figured out how to affix a thin layer of Teflon to aluminum. His wife, Colette, suggested making cooking pans that way. Starting around 1955, Marc made coated pans in their kitchen and Colette peddled them on the street. In 1956 the couple formed the Tefal Corporation in 1956 and opened a factory.

The French government soon declared Teflon safe, which spurred DuPont to seek similar approval in the U.S. Then Thomas G. Hardie, who admired French culture and was familiar with Tefal, began importing Tefal pans, marketing them under the name T-Fal. They were a hit, DuPont finally got in the act, and by the early 1960s, non-stick cookware was everywhere.

Today Teflon is used to insulate tablecloths and carpets, coat steam irons and toughen nail polish, and in pacemakers, dentures, medical sutures, artificial body parts, printed circuits, cables, space suits and Gore-Tex, the favorite fabric of campers and skiers.

But now researchers may have gone Teflon one better.

Jan Genzer, a professor at North Carolina State University, has discovered (by accident) a way to make non-stick surfaces even slipperier. The substance being coated is stretched slightly and then coated with a polymer (Teflon, for instance). When the tension is released, the surface snaps back into place, pulling the polymer molecules together so tightly nothing can bond to them.

Teflon, slick as it is, has irregularities at the molecular level. This new method eliminates those irregularities. Devices coated with these friction-free polymers can bang against each other without scratching. Liquids won’t coat them, and even solvents designed to dissolved the polymer can’t affect them.

Genzer is currently testing the coating’s long-term stability and resistance. If all goes well, within five or six years we could see a whole new wave of non-stick devices, ranging from airplane wings that never ice up to medical implants that never deteriorate.

Pretty slick, eh?

Dr. Thomas Papgiannakis and Dr. Eyad Masad are carefully studying how and why potholes form. Their goal is to help engineers custom-design asphalt to suit the particular ground and climate conditions where a road is built.

In Regina, roads are built on a base 50 to 80 centimetres thick, depending on the traffic load. The bottom layer is clean sand, which aids drainage. Over that goes a layer of dirty sand, then a layer of coarser aggregate, and finally the asphalt. (The city has only been using this “deep granular base” for 15 years or so; older streets were generally built on a concrete base only about 30 centimetres thick, which makes them more susceptible to potholes.)

Regina has a problem with potholes because our roads are built on thick, gooey clay, which traps moisture–and moisture under the road surface is what leads to potholes.

Every pothole begins as a crack. Old pavement cracks because it’s dry and brittle; younger pavement cracks because of the expansion and contraction of the asphalt as the temperature changes.

The first cracks appear in new pavement after about two years. Some run parallel to the roadway, but others, about every 30 metres, run across it. After another couple of years, a second set of cracks shows up, every 15 metres. This process, called “fissuring” or “crocodiling,” continues until somebody seals the cracks–or the pavement breaks up completely.

Crack sealing keeps out moisture, extending the life of the pavement about five years. (New pavement is good for about 18 to 20 years, if properly maintained.) If you can’t keep water out–and sometimes you can’t, depending on when the crack occurs and how successful the seal is–it builds up under the pavement, where the underlying clay helps trap it. If this happens when it’s freezing at night and thawing during the day, it’s bad news. The water expands as it freezes, heaving the pavement up and widening the crack; then thaws, letting in more water, then freezes, pushing everything apart again, then thaws, etc. Water from the underlying clay is also drawn up into the area where freezing is occurring, adding to the problem.

Sometimes there’s more moisture on one side of a crack than the other, which raises one side higher and leaves it less supported underneath. Drive a few cars over it, and eventually a chunk will break way: presto, a pothole! More freezing and thawing and a few more cars, and it can become a veritable canyon.

(By the way, there are technical terms for what cars do to pavement as they drive over it. “Shoving” is the pushing forward of pavement by the wheels of vehicles that brake at traffic lights and stop signs. “Rutting” is the formation of parallel grooves in road lanes, caused by the weight of vehicles.)

We could prevent many potholes by banning cars from the roads during spring thaw, but that’s not very practical in the city. Instead, Dr. Papagiannakis and Dr. Masad suggest, engineers need to tweak their asphalt mix. For instance, they say, you can prevent “shoving” by making sure the rocks in the mix are angular rather than round, and are tightly bound with liquid asphalt. Similarly, extra-strong asphalt can help keep pavement from cracking in freeze-thaw conditions.

The two engineers are promoters of a new approach to designing asphalt mixes called Superpave, which they consider to be the biggest advance in the field since the late 1940s. They’re now heading up the Washington Center for Asphalt Technology, which opened February 1. Its equipment allows them to test asphalt core samples from roads that developed potholes and other problems for microscopic clues to what went wrong, to simulate 10 years of road wear in 24 hours, and even to test asphalt in temperature extremes from 180 degrees Fahrenheit to -30.

Superpave is becoming more and more popular in the States, and while costs for the first Superpave projects were higher than those of traditional methods, the cost difference shrinks to nearly nothing with experience.

Here’s hoping the work of Papagiannakis and Masad, and other brave asphalt researchers, eventually leads to smoother streets right here in Regina.

In the meantime–new shock absorbers, anyone?

Fortunately, Dr. Hazel Prichard hadn’t been forced to take up stree-sweeping because she had lost her job at Cardiff University; instead, she was testing a theory that the streets of Cardiff–and most other major Western cities–are slowly becoming paved with platinum.

Dr. Prichard told a conference in Cardiff last week that the amount of platinum spewed out on city streets from the catalytic convertors used to control pollution is approaching the point where it might be economical to recycle it. Platinum, which is far rarer than gold, is currently priced at $370 U.S. an ounce.

Dr. Prichard figures that in places road dust in Cardiff is approaching 1500 parts per billion of platinum. (By contrast, the solid rock from which platinum is normally retrieved typically only contains 4000 parts per billion.) She also suspects that road dust in major North American cities, where catalytic convertors have been used much longer, could have even higher levels of platinum.

Recycling platinum from road dust might sound a little extreme to the average person, but it may not to people in the platinum industry. They know that platinum is finding more and more uses in our society, uses that most of us aren’t even aware of.

Platinum is silvery white metal, and, like gold, a pure element. South American Indians were using it a thousand years ago, but it was unknown to Europeans until Spanish Conquistadors ran across it in the late 1600s in the Choco region of what is today Colombia. They considered it a nuisance: it interfered with their gold mining. It was considered of so little value that forgers used it to adulterate Spanish gold coins.

However, scientists soon grew interested in platinum because of its unique properties. When it first arrived in Europe, nobody could manage to get it hot enough to melt (because its melting temperature, 1,7774 degrees, is much higher than gold’s), and almost nothing would corrode it. Once somebody did manage to melt it, in 1751, however, industrial uses were quickly found for it. Laboratory apparatus was often made from it because of its resistance to heat and corrosion, and in France by 1780, crucibles for melting glass in were made of platinum (and still are today).

Today, most of us think of platinum in terms of jewelry, and that, too, developed in the 1700s. In 1788, for instance, Francisco Alonso of Spain crafted a platinum chalice (weighing nearly two kilograms!) for Pope Pius VI.

In the 1800s, new refining techniques made platinum useful in ever more ways, from gun parts to batteries to a variety of chemical refining procedures (acid-making, for example). The discovery of new sources of platinum in Russia (which made the first platinum coins in 1822) helped spread platinum throughout society.

Platinum continued to be popular as jewelry in the early part of the 20th century; at the time of the Second World War it was declared to be a strategic metal, and as a result, stopped being used for a long time. Only recently has it begun to regain its pride of place in the jewelry market. Not only is it used to produce rings and other jewelry items itself, but it is combined with gold to make “white gold,” used not only by jewelers but also by dentists. From 1995 to 1996 alone, demand for platinum jewelry grew by 38 percent in the U.S. Recently, Mauro Adami of the Domo Adami fashion house wove together a wedding gown, estimated to be worth $1.5 million U.S., using microscopic platinum fibers threaded into a fabric.

The jewelry market, however, is just the tip of the iceberg as far as uses of platinum goes. Platinum is literally indispensable to our high-tech way of life. By one estimate, one of every five goods manufactured in the world today either contains or is produced using platinum.

The biggest use of all at the moment is for catalytic converters, which suck up about 40 percent of the platinum on the market every year. A catalyst is a substance that can speed a chemical reaction while remaining unaffected itself. In a catalytic converter, a car’s exhaust gases are passed through a honeycomb of small beads coated with platinum and palladium. When the converter is heated and extra air is pumped into it, the hydrocarbons and the carbon monoxide in the exhaust are converted into carbon dioxide and water, while, in a separate reaction, nitrogen oxide is converted into nitrogen, carbon dioxide and water. (The reason cars equipped with a catalytic converter must use unleaded gas is that leaded gas coats the platinum with lead, preventing it from doing its job.)

Platinum is used for many other purposes as well, however. For example, many computer hard disks are coated with an ultra-thin layer of platinum. Non-polluting fuel cells, which are being aggressively pursued by automobile manufacturers as the motive power of the future (and are already used on the space shuttle and as emergency power sources for hospitals and in remote locations), use platinum. Again, platinum serves as a catalyst, allowing a fuel cell to produce energy from a hydrogen-based fuel while producing only water in its exhaust.

Platinum also plays a vital role in sensor technology–tiny amounts of the metal are used in sensors that can detect hitherto undetectable levels of electrical currents or chemical reactions.

Platinum is more valuable than gold not only because of high demand, but also because it is very rare. The entire world’s supply is essentially drawn today from just two places: South Africa and Russia. Extracting it is difficult. For one thing, it is usually found in combination with other metals, and separating it from them is a long, involved process that can take up to six months.

Only around 130 tonnes of new platinum reaches the market each year, less than five percent the amount of gold that’s produced. In fact, all the platinum ever mined would fill a room measuring about eight metres on a side.

It’s no wonder that in Cardiff, they’re talking about sweeping the streets for it. Platinum is so valuable, you don’t want to let a speck escape.

Otherwise, you’re going to have to keep your feet on some kind of flooring: and most likely, that flooring is going to be either carpet or “vinyl.”

Carpets, of course, have been around for a long, long, time, and for most of that time, they’ve been woven from wool or some other natural fiber. But these days, weaving is passé. Instead, more than 80 percent of North American carpets are tufted.

In tufting, hundreds of zigzag rows of yarn, dyed or undyed, are stitched into a roll of carpet backing. The yarn may then be dyed (or dyed again), before it’s washed and glued to a second piece of backing.

The height and density of the yarn loops determine the texture, or “hand” of the carpet. The most popular style is “saxony,” in which all of the yarn loops have been sheared off. “Plush” carpets are similar, except the yarn stitches are closer together, giving you more fibers per square centimetre and, therefore, a softer feel. “Berber” carpets contain unsheared loops of yarn of different heights, which gives the carpet a nubby texture.

Once upon a time, not all that long ago, wool was the fabric of choice for carpets, because it is naturally soil-resistant. (It’s a good thing, too, since sheep are notoriously bad about vacuuming themselves.) Most yarns used today, however, are synthetics, either nylon, polyester or polypropylene (also known as olefin). Nylon is the most popular, and the strongest fiber that’s normally used in homes. Olefin, which is even stronger but has a rougher texture, is most often used in high-traffic, commercial buildings.

Carpet-cleaning is a major industry all by itself (it must be, judging by the number of calls I get from carpet cleaners), and for good reason: the most important thing you can do to preserve your carpet is vacuum it weekly and clean it regularly. That’s because dirt does more than just make your carpet look grungy: it also acts as an abrasive. The particles, ground under foot, wear away at the fibers, destroying the pile.

The difficulty of cleaning carpet is one reason you seldom see it in the bathroom or the kitchen. Instead, you’re more likely to see what is commonly called “vinyl” flooring–although it should be called “resilient” flooring, because it almost certainly isn’t pure vinyl (polyvinyl chloride, or PVC). Some of it, maybe even most of it, may be clay, gypsum or other some other filler. That’s because pure vinyl floors, though very soft and comfortable to walk on, are also expensive.

Many people still refer to all vinyl floors as “linoleum,” but true linoleum–made from finely ground wood and linseed oil–hasn’t even been manufactured in North America for years. It has to be imported from Holland.

Vinyl–excuse me, “resilient”–flooring consists of several layers: a backing, a cushion layer, and a wear layer. What makes vinyl flooring attractive is the fact that it can be decorated with a vast number of patterns. How those patterns are applied has a lot to do with both the price and the look of the flooring.

The traditional method is rotogravure, in which the pattern is printed right on the backing with a huge printing press. A more expensive method is the inlaid pattern, which might be built up over several layers. To get an inlaid pattern, vinyl granules and sometimes bits of quartz ore granite are laid over a printed surface. An inlaid pattern is less apt to wear away in high-traffic areas; it also looks more like the granite or marble it’s often meant to imitate.

The wear layer goes over top of the pattern: it’s usually either clear vinyl or harder and longer-lasting urethane. The thicker the wear layer, the more expensive the vinyl.

Resilient flooring that has a wear layer is also called “no-wax.” (In fact, my landlady specifically forbade me to wax the kitchen floor.) Floor wax is really just a wear layer that’s applied after the fact. A top-of-the-line vinyl floor only requires regular sweeping or vacuuming and occasional damp-mopping (again, grit is the enemy).

Ugh. “Sweeping,” “vacuuming,” “mopping.” Now that I’ve crossed over into talking about housework, I’m afraid I’m going to have bring this column to a close.

Some things are just too horrible to write about.

“Wax,” says the encyclopedia, is the name “applied originally to naturally occurring esters of fatty acids and monohydric alcohols.” Esters, says the same encyclopedia, are compounds formed by the interaction of acids and alcohols with the elimination of water.

Enlightened? Perhaps not. But don’t worry about it too much, because these days, the word “wax” is also applied to any number of non-esters which can be obtained in a variety of ways from a variety of sources, but all share similar characteristics.

Typically, a wax has a dull luster, a somewhat greasy texture, softens gradually while being heated–which means it can be easily shaped while warm–and, if heat continues to be applied, eventually turns into a liquid.

The granddaddy of all waxes is undoubtedly beeswax: not that it’s been around longer than other natural waxes, just that humans have been using it longer, and anthropocentric chauvinists that we are, we think that makes it very important.

Bees produce wax to create chambered nests in which to lay eggs and hatch more bees. They also store food in these chambered nests, which aren’t called “honeycomb” for nothing. Humans have been gathering honey for food for probably as long as they’ve been human, and as early as 3000 BC the Egyptians and Cretans learned how to make candles out of the beeswax that is inevitably harvested along with the honey. (Modern beekeepers harvest about 18 kilograms of beeswax per 910 kilograms of honey.) The slow-burning wax kept the wick of the candle from flaring up and burning out in a matter of seconds: the result was a long-lived and cheap source of illumination.

The Egyptians also used beeswax as a base for cosmetics, and while candles have probably consumed more wax than anything else over the centuries, wax continued (and continues) to be used for a great many other purposes.

The many uses for wax has led to a constant search for new types of wax, both natural and synthetic. Another animal besides bees that provides wax (much to its detriment) is the sperm whale. “Spermaceti” is a wax extracted from the head cavity and blubber of sperm whales that has valuable lubricating properties. (“Ambergris” is another valuable wax from sperm whales, but unlike spermaceti, harvesting it doesn’t require killing a sperm whale. Ambergris is secreted in the intestines of sperm whales and is found floating in tropical oceans. It’s used in perfumes. Aren’t you glad I told you that?) Lanolin is another well-known wax; it’s produced by sheep (it waterproofs their fleece).

Other natural waxes come from mineral sources; the best known of these is paraffin, which is extracted from petroleum.

Fossil-fuel based waxes now account for 95 percent of the waxes used commercially, but that other five percent, primarily plant-based waxes, accounts for 25 percent of the revenue from the sale of waxes. Many tropical and sub-tropical plants have waxy leaves, to retain moisture despite exposure to the blazingly hot sun. One valuable example is the carnauba palm, cultivated in Brazil. The wax beaten from its leaves is very hard and has a high melting point, which has made it the key ingredient in fine waxes for automobiles.

Even a partial list of the ways in which waxes are used is mind-boggling. Besides the uses I mentioned at the start of the column, waxes are used to coat milk and juice containers; in the making of carbon paper; in lacquers and varnishes; in skin creams and cosmetics; to polish floors, furniture and shoes; as electrical insulators, and even to coat suppositories. (Those who have had them are grateful.)

Our own bodies produce wax: earwax. It may seem useless, embarrassing, or even a nuisance (although it usually works its way out of the ear, it can occasionally harden inside the ear canal, causing loss of hearing until a doctor flushes it out), but in fact it serves a useful purpose. Produced by modified sweat glands, the wax, along with the hair in the ear canal, helps keep foreign matter (dirt, insects, etc.) from entering the ear.

And now, reader dear,
Please lend me your ear,
And listen, sympathetic:

You’ve read all the facts
I wrote about wax–
Now I end by waxing poetic!