In 1820, Danish physicist Hans Christian Ørsted noticed that a wire carrying current made a nearby compass needle swing. For the first time, electricity and magnetism appeared as two sides of one phenomenon. Within a few years, the discovery led to the electromagnet, then to the electric motor. Nearly every electric machine today descends from it.
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.