Superconductivity: Current in a Cape and Thermal Tights
Table of Contents
By Kristen Coyne
Woe is us.
Our utility bills are up. Politicians want to drill for oil in the Gulf of Mexico and other ecologically sensitive areas. Global warming has already begun to harm the planet. As we make ever greater demands on our limited resources, most of us worry about the long-range consequences. What can be done?
Scientists have been exploring many options, from more practical applications of solar energy to safer nuclear power plants. Also laboring toward a solution, at the MagLab and elsewhere, are physicists using mammoth magnets and a host of other tools. With them they hope to harness the power of a phenomenon they have experimented with for nearly a century and theorized about for even longer, but have yet to master, or even fully understand: superconductivity. Think of it as electricity on steroids.
No, wait – that’s not quite right. While the word “steroids” does convey the incredible power of superconductivity, it also, incorrectly, suggests substantial sweat and effort. And the beauty of this physics phenomenon is in the lack of effort required for superconducting current to flow.
Here’s another stab at defining superconductivity. It’s like those perfect days that sometimes come our way, when everything goes magically right, when all obstacles are removed from our paths and we fly through the hours, accomplishing every task almost effortlessly, as if on autopilot.
Yes, that is superconductivity: great efficiency achieved with great ease. In fact, when you have a superconducting current going, it can keep on going and going and going – long after you unplug the machine, long after the Energizer Bunny calls it quits, years after, bored senseless, you stop waiting around to see how long it would last.
Sounds miraculous, doesn’t it? Well, it's a reality. In fact, the MagLab has superconductivity to thank for one of its most powerful tools: Its 900 MHz ultra-wide bore magnet. One of the most powerful superconducting magnets in the world, it is used for important research in nuclear magnetic resonance (NMR). Since it was first charged in July 2004, it has been continually conducting electricity by itself – no plug needed.
Here’s the rub: While superconductivity, once achieved, runs like a dream, creating the environment and tools that make it possible is a substantial chore.
PHYSICS FACTOID: In 2003, the world consumed 14,768 billion kilowatt hours of electricity. Assuming high economic growth, that number is projected to rise to 28,870 billion by the year 2025. (If you use a 100-watt light bulb for one hour, you have used 100 watts of power, or 0.1 kilowatt hours.)
The pursuit of superconductivity makes for an exciting story, full of suspense, red herrings, scandalous behavior on the part of certain atomic particles, a take-home message on the benefits of cooperation and, potentially, a very happy ending. And, as do all good stories, ours has a hero. We will call him, simply, SuperConductor.
But we are getting ahead of ourselves a bit here. Before we can comprehend our caped crusader’s prodigious powers, we need to meet his mild-mannered cover: Spark Kent. Spark’s day job is at the local power plant, conducting electricity to our community’s homes and businesses in pretty much the same ho-hum way it has been done since the late 1800s. Though Spark works hard, it’s not hard enough … not with the energy problems facing the planet. The atoms are restless, the electrons are unproductive: Someone needs to come to the rescue.
For those of you needing a quick refresher course in the behavior of atoms – knowledge essential to understanding superconductivity – proceed to the next section. Otherwise, feel free to jump ahead to page 3.
Next Page Electron Done Me Wrong: Atoms in a Nutshell
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