To freeze, water needs a seed: a speck of dust, a scratch, an impurity around which a crystal can start. Without one, it can stay liquid well below 0 °C, a state called supercooling. Clouds are full of supercooled droplets. They freeze instantly when they hit an aircraft wing, which is why planes need de-icing systems.
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.