Touch a metal handle with one hand and a wooden table with the other, in the same room: the metal feels icy. Yet both are at the same temperature. Your skin does not sense temperature itself, but how fast it is losing heat. Metal conducts heat hundreds of times better than wood, so it drains warmth from your hand much faster.
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.