In 1935, Erwin Schrödinger imagined a cat shut in a box with a radioactive atom, a detector and poison. On a naive reading of the theory, the cat would be both dead and alive until someone opened the box. Schrödinger meant to show how absurd it was to apply quantum rules this way to everyday objects. His jab became the field's mascot.
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.