It’s a Bird, It’s a Plane, It’s … : Superconductivity in a Nutshell

Someone has! Enter our hero, SuperConductivity, to save the day! His power: plowing past obstacles as if they weren’t even there.

The key to achieving superconductivity is keeping fidgety atoms out of the way of the flow of electrons. The hotter those atoms get, the more fidgety they get: That’s why the atoms in your ice cubes are slow-pokes compared to those in your tea, which in turn trudge like turtles compared to the atoms zipping about in the steam coming out of the kettle.

So to get atoms to truly chill out, you need to turn the A/C up.

Way up.

The fundamental laws of physics tell us that you can never suck all the energy out of a chunk of matter. But you can come pretty close and, as it turns out, pretty close is close enough.

How cold is close enough?

First, let’s define the bottom of the temperature barrel. As far as we know, there is no limit to how hot the universe could get. But, thanks to a gentleman named William Thomson (Lord Kelvin to you), we know that there is a definite limit to how cold it can get. Scientists call it 0 kelvin (0 K), or absolute zero. You might call it -273 degrees Celsius, -460 degrees Fahrenheit, or just gosh darn frosty. By comparison, the coldest temperature ever recorded on Earth was -129 degrees Fahrenheit.

You may be relieved to learn that you don’t need to get all the way down to absolute zero in order to achieve superconductivity. This fact came as quite a surprise, though, to the scientist who first, quite unexpectedly, achieved that state, which until then had only been theoretical. That happened in 1911.

Dutch physicist Heike Kamerlingh Onnes was a pioneer in liquefying hard-to-liquefy gasses. At the time he was the first, and only, person to create and work with liquid helium, which requires a teeth-chattering 4 K. He wanted to see how metals (for this experiment he used mercury) behave when exposed to such extremes.

As you’ve guessed by now, Onnes discovered that the metal lost all resistance, and electrons flowed through freely. As a result, he became known as the father of superconductivity.

What can speed through matter in a single bound? Not a bird, not conventional electric current, but our hero, SuperConductivity!

As a hero, SuperConductivity shows tremendous potential. A lot of famous and not-so-famous scientists have for a century worked to unlock its secrets. They have made considerable progress, creating experimental currents that run for years, developing highly valuable applications such as magnetic resonance imaging (MRI) and “levitating” maglev trains. The age of superconductivity is still young, but it is here.

But like other superheroes, SuperConductivity has his nemesis. Let’s call him Iceman.

It’s true that extreme cold is necessary for superconductivity. But Iceman is still our bad guy because he makes the process quite difficult (liquid helium is expensive and cumbersome to work with) and prohibitively impractical. Scientists have been battling this enemy ever since 1911, as we’ll see in a bit.

Still, Onnes’ news was revolutionary, holding all kinds of promise for humankind. It would be many decades, though, before scientists could begin to develop applications for the discovery. Heck – for many years they didn’t even know how superconductivity really worked.

Next Page Two by Two: Cooper Pairs

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Links | Full Article