The outer bow comes from rays that bounce twice inside each raindrop instead of once, and that extra reflection flips the colour order: red inside, violet outside. Between the two bows, the sky looks noticeably darker. That strip has a name, Alexander's dark band, after a philosopher who described it around 200 AD.
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.