
Chapter 1
Light and color
1.1 Light as color stimulus
We live immersed in electromagnetic fields, surrounded by radiation of
natural origin or produced by artifacts made by humans. This radiation has
a dual behavior of wave and particle, where the particles can be considered
as packets of electromagnetic waves. Waves are characterized by their wave-
length, the distance between two consecutive peaks. Of all the radiation that
continuously reaches our eyes, we are only able to see (i.e. our retina pho-
toreceptors are only sensitive to) electromagnetic radiation with wavelengths
within the range of 380nm to 740nm (a nm or nanometer is one-billionth of