In 1964, Murray Gell-Mann proposed that protons and neutrons are made of smaller particles. To name them, he picked a word from James Joyce's "Finnegans Wake": "Three quarks for Muster Mark." The number three fit perfectly, since a proton contains exactly three quarks. And these particles are never seen alone, always bound together in groups.
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.