Tag Archives: superconductivity

Defying Gravity using Science

Gravity defying feats have long been a favored pastime for magicians and illusionists. Well, science has now caught up to and surpassed our friends with sleight of hand. Check out this astonishing video (after the 10 second ad) of a “quantum locked”, levitating superconducting disc, courtesy of New Scientist.

[div class=attrib]From the New Scientist:[end-div]

FOR centuries, con artists have convinced the masses that it is possible to defy gravity or walk through walls. Victorian audiences gasped at tricks of levitation involving crinolined ladies hovering over tables. Even before then, fraudsters and deluded inventors were proudly displaying perpetual-motion machines that could do impossible things, such as make liquids flow uphill without consuming energy. Today, magicians still make solid rings pass through each other and become interlinked – or so it appears. But these are all cheap tricks compared with what the real world has to offer.

Cool a piece of metal or a bucket of helium to near absolute zero and, in the right conditions, you will see the metal levitating above a magnet, liquid helium flowing up the walls of its container or solids passing through each other. “We love to observe these phenomena in the lab,” says Ed Hinds of Imperial College, London.

This weirdness is not mere entertainment, though. From these strange phenomena we can tease out all of chemistry and biology, find deliverance from our energy crisis and perhaps even unveil the ultimate nature of the universe. Welcome to the world of superstuff.

This world is a cold one. It only exists within a few degrees of absolute zero, the lowest temperature possible. Though you might think very little would happen in such a frozen place, nothing could be further from the truth. This is a wild, almost surreal world, worthy of Lewis Carroll.

One way to cross its threshold is to cool liquid helium to just above 2 kelvin. The first thing you might notice is that you can set the helium rotating, and it will just keep on spinning. That’s because it is now a “superfluid”, a liquid state with no viscosity.

Another interesting property of a superfluid is that it will flow up the walls of its container. Lift a bucketful of superfluid helium out of a vat of the stuff, and it will flow up the sides of the bucket, over the lip and down the outside, rejoining the fluid it was taken from.

[div class=attrib]Read more here.[end-div]