Throw water into a hot pan, and it will sizzle so fast that the drops actually levitate across the surface. Physicists have now taken this phenomenon, called the Leidenfrost effect, a step further: Using magnets, the scientists directed droplets of liquid oxygen to speed up, slow down and change course as they scoot across a sheet of glass.
Magnetic fields force the tiny blobs to travel in a mesmerizing dance, says David Quéré, a physicist at ESPCI Paris Institute of Technology in France. He and his colleagues describe the work in an upcoming Physical Review E.