In 1925, at Bell Labs, Clinton Davisson and Lester Germer were bouncing electrons off nickel when air leaked into the apparatus and oxidized the sample. To clean it, they heated it strongly, turning it into a few large crystals. The electrons then began to diffract like waves. Davisson went on to share the 1937 Nobel Prize in Physics.
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.