What human can see around,in other words the reason why man perceive things on his
eyes, is because of light.My intention here is to discuss the properties of light.
What is light made off?
Light is what's called an "electromagnetic wave", just like radio waves, microwaves,
X-ray waves, etc. Electromagnetic waves typically start when an electric charge jiggles
back and forth.
Depending on the "frequency" of the electromagnetic wave, you get different kinds
of waves.For example, radio waves have a pretty low frequency - i.e: the peaks in
a radio wave are pretty far apart. Next comes microwaves, then infrared light.
Next is the visible spectrum where the different colors of light that people can see
(will discuss about Colour, later in this blog), followed by ultraviolet light(see figure 1).
Then waves with higher frequency are called X-rays and still higher are gamma rays -
these have the peaks closest together.
Sometimes you'll hear that light is made of photons. What that means is that when
light is absorbed or emitted, the energy in the wave comes in lumps. The size
of those lumps (or "quanta") of energy depends on the frequency. The higher
the frequency the more energy per photon.
figure 1
