OXYGEN has defied gravity and dripped upwards, thanks to the weird effects of
super-conductivity.
In a famous scientific party trick, a magnet hovers above a superconductor
cooled by liquid nitrogen. It floats because the magnet induces supercurrents in
the superconductor that exert an upward force on the magnet.
Now Damian Hampshire and colleagues at Durham University have shown that in
this set-up, liquid oxygen condenses out of the air onto the cold superconductor
then bizarrely drips upward to the magnet, where it boils off (Nature, vol 415,
p 860). This is because the field around the floating magnet magnetises the…
