In 1999, physicists in Vienna sent fullerene molecules, tiny soccer balls made of 60 carbon atoms, through a grating of slits. They produced an interference pattern, the signature of a wave. The experiment has since worked with molecules of around 2,000 atoms. Nobody has yet found where the quantum world ends and the everyday world begins.
Cooled below −183 °C, oxygen turns into a pale blue liquid. Pour it between the poles of a strong magnet and, instead of flowing away, it hangs suspended between them. The reason lies in its unpaired electrons, which respond to the magnetic field. Liquid nitrogen, by contrast, is colourless and pours straight through.
In 2012, Felix Baumgartner jumped from a capsule hanging beneath a balloon, about 39 kilometres up. In that extremely thin air almost nothing slowed him down, and he reached around 1,358 km/h in free fall, or Mach 1.25. He became the first person to exceed the speed of sound with nothing but his own body.