A fridge does not make cold: it pumps heat out of its interior and dumps it through the coils at the back. Doing so uses electricity, which also ends up as heat. With the door open, it returns to the room whatever it removes, plus its motor's energy. The result is a kitchen that slowly warms up, exactly as thermodynamics predicts.
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.