Vaporising one gram of water takes about 2,260 joules, more than five times what it takes to heat it from 0 to 100 °C. When steam hits your skin, it condenses back into liquid and dumps all that hidden energy into you at once. At the same temperature, a jet of steam burns far worse than a splash of boiling water. Mind the saucepan lid.
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.