91av

Thirty years is a long time to wait for the next big thing. But for half of 91av‘s lifetime, a select group of researchers has been sure that a world-changing discovery is just around the corner. If it happened it would bring “revolutionary change for our normal life,” according to Yanming Ma of Jilin University in Changchun, China.

The breakthrough in question? A superconductor that operates at room temperature and ambient pressure. Sounds riveting, I know. But bear with me.

Superconductors are materials that conduct electricity with no resistance. The phenomenon was first discovered by Dutch physicist Heike Kamerlingh Onnes, who in 1911 saw mercury’s resistance drop to zero at 4.2 degrees above absolute zero. Other materials were found to be superconducting at slightly higher temperatures, but the need for extreme refrigeration limited the usefulness of the phenomenon.

Until 1986, that is. That was when we discovered the high temperature superconductors, which abruptly stop resisting below roughly 100 kelvin (which is -170 °C: the term “high temperature” is a relative one). Suddenly, creating room temperature superconductors didn’t seem so far-fetched.

That second great leap forward hasn’t happened – yet. So far we have not bettered what we found 30 years ago, says Paul Attfield of the University of Edinburgh, UK. Materials have been discovered that superconduct at somewhat higher temperatures, but only when under extremely high pressures.

For now, superconductors remain entirely impractical for the killer applications that would allow them to change the world: transport and electrical power transmission.

Superconductors are a strong barrier to magnetic fields, meaning that a magnet will levitate above them. This makes them perfect for highly efficient and very fast maglev trains that hover above their tracks, suffering no energy loss from friction.

Energy loss, or rather its absence, is also key to their usefulness in supplying power. When we send electricity from power stations to consumers, it runs through wires that resist its flow. The result is that we have to generate far more power than we ever get to use.

With superconducting cables, we lose none. That also means that a battery using superconducting materials could remain charged forever. Both technologies would help solve many of the world’s energy problems at a stroke without having to rely on the other great future energy revolution, nuclear fusion (see “The world in 2076: Artificial starlight has made energy free“). “Humankind would live in a world of superconductivity,” says Mikhail Eremets of the Max Planck Institute for Chemistry in Mainz, Germany.

There is no fundamental theoretical roadblock to room-temperature superconductivity, says Eremets. In August, a team led by Ivan Božović of the Brookhaven National Laboratory in Upton, New York, published a groundbreaking that might point the way. “It suggests a strategy change in our quest,” Božović says. “I’m optimistic.”

This article appeared in print under the headline “What if… We discover room temperature superconductors?”