Prepare to have your mind blown.
You may have seen levitation tricks performed by magicians, but rest assured that they can’t beat this: quantum levitation. The video above was captured at the 2011 ASTC conference, a gathering of scientists in Baltimore, Maryland, with the purpose of demonstrating “how science centers and museums are putting new ideas to practical use to serve their communities.” The School of Physics and Astronomy at Tel-Aviv University has put together this physics experiment showcasing quantum superconductors locked in a magnetic field.
While the video fails to explain the science of what is happening here, the complementary website is helpful. The white round disk (essentially a sapphire wafer coated with a thin layer of yttrium barium copper oxide) is cooled to below negative 185 degrees C. At that temperature (dubbed the critical temperature), the material becomes superconductive, meaning that it has zero electrical resistance. From the website:
Superconductivity and magnetic field do not like each other. When possible, the superconductor will expel all the magnetic field from inside. This is the Meissner effect. In our case, since the superconductor is extremely thin, the magnetic field DOES penetrate. However, it does that in discrete quantities (this is quantum physics after all! ) called flux tubes.
Inside each magnetic flux tube superconductivity is locally destroyed. The superconductor will try to keep the magnetic tubes pinned in weak areas (e.g. grain boundaries). Any spatial movement of the superconductor will cause the flux tubes to move. In order to prevent that, the superconductor remains “trapped” in midair.
And in case you’re wondering: are there practical applications for quantum levitation? The answer, of course, is yes!