why is it so that when sunny the tarmac roads appear having water

Question: why is it so that when sunny the tarmac roads appear having water
- Keywords:
  road,
  sun,
  tarmac,
  water
Asked by abhb266 to Beatrice, Charles, George, Kamal, Patricia on 17 Jan 2017.
- Charles Kamau answered on 17 Jan 2017:
  
  This phenomenon is called mirage. It occurs when the light from the sky is refracted by the hot surface of the tarmac. Same thing that happens when you place a pencil in water; it gets refracted.

Question: why is it so that when sunny the tarmac roads appear having water