Light will travel slightly slower than this through air, and some wild experiments have actually slowed light to a crawl and seemingly made it go backward, but at the scales encountered in our everyday lives, light is so fast that we perceive our surroundings in real time.

Look up into the night sky and this illusion begins to falter.

"Because light takes time to get here from there, the farther away 'there' is, the further in the past light left there, and so we see all objects at some time in the past," explains Floyd Stecker of NASA's Goddard Space Flight Center in Greenbelt, Md.

 Source : MSNBC Space