In the early 1950s, Clair Patterson worked out the age of the Earth, about 4.55 billion years, using lead isotopes from a meteorite. But his measurements were first ruined by contamination everywhere: lead from gasoline had invaded the air, the water and our bodies. He spent decades fighting this poison until it was phased out of fuel.
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.