ABSTRACT
Electromagnetic waves are all around us. The extreme large-
frequency spectrum allows us to perceive the world on different
length scales, from a few hundreds of nanometers for visible light to
centimeters for radar waves. Any source of visible light, the sun or a
simple lamp, emits light rays that are reflected, refracted, diffracted,
absorbed, re-emitted, and scattered from every single piece of
matter or even from isolated atoms or molecules encountered on
its path. Light rays that reach our eyes have undergone a huge
amount of such events and store a lot of information. Trying to
decode information from the scattered light that reaches our eyes
is something that our brain does continuously in our daily lives,
allowing us to perceive and have an image of the surrounding world.
