In the 1770s, Antoine Lavoisier worked out the role of a gas in burning and breathing. He called it oxygen, "acid-maker," because he wrongly believed every acid contained it. Hydrochloric acid would prove him wrong. He also named hydrogen, "water-maker," and that one turned out perfectly accurate.
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.