how is it that a rocket can be controlled by a computer that is somewhere on earth when the rocket is in space?

Question: how is it that a rocket can be controlled by a computer that is somewhere on earth when the rocket is in space?
- Keywords:
  computer,
  earth,
  rocket,
  space
Asked by tmcd123 to Cathal on 13 Nov 2013.
- Cathal Cummins answered on 13 Nov 2013:
  
  The computer communicates with the rocket using radio waves. Radio waves are like light waves — they travel at the speed of light and the Earth’s atmosphere (it’s just air) doesn’t stop them so they have no problem getting to a rocket!

Question: how is it that a rocket can be controlled by a computer that is somewhere on earth when the rocket is in space?