In 2021, physicists at the University of Bremen chilled a cloud of rubidium atoms to about 38 picokelvin, or 38 trillionths of a degree above absolute zero. Their trick was to drop the whole experiment down a 120-metre tower, so gravity no longer disturbed the atoms during free fall. That is far colder than any natural place known in the Universe.
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.