In 1900, Max Planck was trying to explain the light given off by hot objects. He only succeeded by assuming energy is exchanged in tiny indivisible packets, called quanta. He saw it as a mere mathematical trick and later described it as "an act of desperation." That stopgap ended up founding the whole of quantum 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.