ÐÓ°ÉÔ­´´

HERE are three words guaranteed to make most lay people yawn and most
scientists roll their eyes: high-temperature superconductivity. If you’re a
little hazy about the concept, take a trip back to 1986. That was the year a
team at IBM in Zurich made superconductivity sexy when they invented a material
that offered absolutely no resistance to electricity. Currents simply flew
through the material, without creating any of the usual heat—and hence
woeful energy wastage—that plagues ordinary copper wiring. It had been
seen before but only at impracticably low temperatures close to absolute zero.
Soon teams were seeing it at a comparatively balmy –173 °C.

Suddenly we were on the cusp of change. Next up would be materials that
performed this magic at room temperature. Ugly, inefficient power cables and
pylons would give way to gossamer-thin wires carrying all the energy we need.
Everything from TVs to computers to hairdryers would become super energy
efficient, wasting not a watt.

Fifteen years on and room-temperature superconductivity seems to have joined
cold fusion in the dustbin of over-hyped breakthroughs. There are no materials
that perform the magic without being cooled. The shouts of eureka have all been
false alarms. Perhaps the scientists behind the latest cry really have cracked it
(see p 7). But the omens do not look promising.

Yet whatever the final verdict on this claim, high-temperature
superconductivity is not a lost cause. Far from it. While the search for
ultra-sexy room-temperature materials has faltered, scientists have produced a
whole gallery of more mundane materials which superconduct at lower but still
accessible temperatures. Now some of these materials are about to hit the real
world.

In Detroit, for example, some 30,000 homes are already getting power down
superconducting cables. Liquid nitrogen flows through the cable to cool the
material and make it superconducting. Meanwhile, American naval engineers are
building superconducting motors to power ships. Coiled superconducting wires can
carry vast currents without heating. As a result, they generate massive magnetic
fields which can be harnessed to make astonishingly compact, powerful
motors.

Also coming along nicely are plans to build superfast computers. With
superconducting wires, the theory goes, it should be possible to make computer
chips smaller and pack them closer without the danger of overheating. Engineers
may not need the holy grail of a material that works at room temperature to
realise many of their superconducting dreams.

The problem is that today’s prototype wires remain staggeringly expensive,
and their performance far from perfect. Superconducting cables might one day
save power companies (or their customers) tens of billions of dollars a year and
help to slash greenhouse emissions. But not yet. That is why it is imperative
that the hunt continues for simpler materials which will work at still higher
temperatures. And why the rest of us should neither yawn nor roll our eyes.