Yesterday my Grandson,three years, was asking me why there are only seven colors.
I replied to him about the Rainbow and we see the colors VIBGYOR in our daily Life.
He asked me immediately why there should be Seven Colors in the rainbow , not Two or Ten?
I could not explain him and told him so.
Later I recollected that Indian Philosophy has answer to this one.
The Vaisehika system of Indian Philosophy has a very advanced Atomic Theory.
According to the Vaiśeṣika school, the trasareṇu (dust particles visible in the sunbeam coming through a small window hole) are the smallest mahat (perceivable) particles and defined astryaṇukas (triads). These are made of three parts, each of which are defined as dvyaṇuka (dyad). The dvyaṇukas are conceived as made of two parts, each of which are defined as paramāṇu(atom). The paramāṇus (atoms) are indivisible and eternal, they can neither be created nor destroyed. Each paramāṇu (atom) possesses its own distinct viśeṣa (individuality).
The measure of the partless atoms is known as parimaṇḍala parimāṇa. It is eternal and it cannot generate the measure of any other substance. Its measure is its own absolutely”
So the Atoms of the Perceiver and the Perceived(object) atoms for recognition by respective senses.
We become aware when these two corresponding Atoms get connected.
Knowledge is possible when the one who Perceives is connected to the Perceived.
The fact that we do not see any colors is because of the unused Atoms of the Retina not connecting to The Atoms of the Objects which may contain more colors.
People who have tapped their full potential can see what we can not see.
We, not having realized our potential, can not see more than Seven colors.
Now look what Scientists say on this subject.
(PhD physicist responds) The eye perceives six colors in the rainbow. Red, orange, yellow, green, blue and violet. (some people include the violet color of Indigo as a separate color.) But there are also colors in the infrared and ultraviolet present as well. The rainbow is caused by diffuse refraction of sunlight in water droplets. The source of the light is the sun’s photosphere. While each atom in the photosphere may emit light at one quantum frequency, the sun is so hot that doppler shifting of the light causes the lines to “fuzz out” so that you see essentially a continuous spectrum of light. The strictly correct answer, would then be, “an infinite number”
“The unseen color aftereffect of an unseen stimulus: Insight from blindsight into mechanisms of color afterimages”