Considering that rainbows are visible only when certain conditions are met, one may reasonably ask, “Who set the conditions?”
In 1666 Newton demonstrated that normal white light is composed of all the colors. By refracting (bending) light through a glass prism, he separated it into its component colors. Then, by sending the refracted light back through another prism, he combined the components back into white light, proving that the prism itself wasn’t creating the colors. He also figured out that many materials refract light, including water. Raindrops refracting and reflecting light are the key to producing a rainbow, which, he concluded, is a successful collaboration between the sun, zillions of tiny raindrops (sometimes less than one millimeter across), and our eyes, which must be observing those raindrops at just the right angles.
Three conditions are mandatory to see a rainbow. First, the sun needs to be behind us. Second, there must be raindrops ahead of us, whether miles or a few hundred feet away. Third, the sunlight must reach the raindrops without any obstruction, such as clouds. When a ray of light enters a raindrop and refracts, it separates into component colors. Red light refracts, or bends, the least, while violet light refracts the most. The different-colored rays travel toward the back of the raindrop. Some of the light exits, but some of it bounces back at an angle, towards the front of the raindrop. Some of the light reflects more than once, but to keep this discussion simple, I’ll restrict it to the light that reflects just once. When light exits the front of the drop, some of it again refracts, separating the colored rays still further.
Key to why we see a rainbow is that red light exits the raindrop at angles that are always smaller than 42 degrees from the direction of the sunlight entering the drop. And this is the same for all raindrops, for the sun is very far away. The angle at which the red light exists can be anything less than 42 degrees, and the maximum angle is different for different colors. For violet light, the maximum angle is about 40 degrees. The different maximum angles for each color account for the stripes in the rainbow.
How does one spot a rainbow under the right conditions? Facing the rain, imagine a line from the sun, through your head, and to the far end of your shadow. The higher the sun, the steeper this line is and the shorter your shadow. At about 42 degrees away from that line – straight up, to the right or left – one can see the red band. At about 40 degrees away from it – up, right or left – one can see the violet band.
“The whole cosmic order is under Me. By My will it is manifested again and again.”
– Bhagavad-gıta (9.8)
Since the 40-degree band is closer to the imaginary line than the 42-degree band, the violet band is on the inside of the red band, with the other colors in between.
Now you might wonder, at the maximum angle for violet light, do we see only violet light? After all, red light can also emerge at 40 degrees, as it is smaller than 42 degrees. The answer is that at the maximum angle for any color, that color dominates. And why is the rainbow a bow and not straight? Go back to that imaginary line from your head to the end of your shadow. When you measure 42 degrees in all directions – away from the imaginary line – you are tracing an arc of color. But not all rainbows are full arcs; some are just little pieces. That happens when there aren’t enough raindrops in all directions or when certain parts of the rainbow are in the shadow of obstructing clouds. When the sun is high, the rainbow may just peek above the horizon, whereas just before sunset or around sunrise, when the sun is low and your shadow is long, then a rainbow may be enormous.
The Challenge of Universal Constants
Modern science can’t explain why the physical laws are as they are, or why the universal constants have the values they have. However, when we look closely at the Vedic scriptures we get much insight. When I said that we cannot see the light from the raindrops beyond 42 degrees, did it occur to you that it is 42 degrees because that’s how it is ordained by the Supreme Lord’s inconceivable energy? If yes, then you are fortunate, for you can easily learn all there is to know about rainbows and beyond. If no, then while you can find out experimentally that it is indeed 42 degrees, you may erroneously infer that it randomly happens under “right conditions” for the rainbow to be visible to your eyes. That inference is precarious, for you would explore ways to deny the supreme intelligent designer, who through His diverse energies creates wonderful precise art like a rainbow. And not just rainbows; there is a perfect brain behind all the natural physical laws. “Brain” implies a person. That person, Lord Krishna , is the supreme scientist under whose will the whole cosmos works. In Bhagavad-gita (9.8) He says, prakrtim svam avastabhya visrjami punah punah: “The whole cosmic order is under Me. By My will it is manifested again and again.”
A rainbow governed by precise scientific laws of reflection and refraction is also a work of art. When the right conditions are met, intela rainbow can manifest by the subtle energies of the Supreme Lord, just as a rose can bloom overnight because of those same energies. Krishna is the greatest artist. When we observe the artistic work in a rainbow, we can understand that the color adjustment, the shape, and so on, have demanded the minute attention of an intelligent designer, for if the rainbow were truly random, why would it follow exact laws of certain angular shifts? But the gross materialist, not seeing the hand of God in such manifestations, concludes that the Absolute Truth is impersonal. Actually, the Absolute is personal, but independent. Unless engaged in His service one cannot fathom how He acts. Everything is revealed in loving devotional service.
Indra and the Sun-God
The Supreme Lord does not personally paint the rainbows, for His energies in the form of demigods such as the sun-god and the raingod (Indra) act in unison. Rainbows only appear to come into being without an artist’s aid. In the normal course, Lord Indra and the sungod are involved together in the creation of rainbows, which occur under prescribed laws. But since Indra and the sun-god are specially empowered, there is exception to the laws if these demigods so desire. For instance, at the outset of the battle between Indra’s son Arjuna and the sun-god’s son Karna, an interesting symbolic confrontation took place between Indra and the sun-god. Thundering clouds that flashed with lightning suddenly covered the sky, and without the cooperation of the sun, a profusion of rainbows appeared. Seeing Lord Indra affectionately sending his signs to encourage his son Arjuna and forecast his victory, the sun vanquished the clouds that came too near his son Karna. Thus Arjuna was covered by the shadow of Indra’s clouds, whereas Karna was fully exposed, bathed in the rays of the sun.
When Lord Krishna entered Dvaraka, it appeared “as if a dark cloud were surrounded
simultaneously by the sun, moon, lightning, and rainbows.”
The word guna can mean “string” or “mode.” Just as a rainbow has no string, the appearance of the Personality of Godhead has nothing to do with the modes of material nature. Srimad-Bhagavatam (10.20. 18) states: “When the curved bow of Indra [the rainbow] appeared in the sky, which had the quality of thundering sound, it was unlike ordinary bows because it did not rest upon a string. Similarly, when the Supreme Lord appears in this world, which is the interaction of the material qualities, He is unlike ordinary persons because He remains free from all material qualities and independent of all material conditions.” In their purport to this verse, the disciples of Srila Prabhupada quote his commentary:
Sometimes, in addition to the roaring thunder of the clouds, there is an appearance of a rainbow, which stands as a bow without a string. Usually, a bow stays in the curved position because it is tied at its two ends by the bowstring; but in the rainbow there is no such string, and yet it rests in the sky so beautifully. Similarly, when the Supreme Personality of Godhead descends to this material world, He appears just like an ordinary human being, but He is not resting on any material condition. In the Bhagavad-gita, the Lord says that He appears by His internal potency, which is free from the bondage of the external potency.
The bow of the Supreme Lord or His intimate devotee like Arjuna is often compared to a rainbow.
When Hanuman met Rama and Laksmana at the edge of the lake by Rishyamukha Hill, he prostrated himself before the princes and inquired respectfully, “What brings you two shining ascetics to this region? You appear like a pair of royal sages fit to rule the entire world, and Your massive bows glow like rainbows.”
Now, consider what Srimad- Bhagavatam (1.11.27) states: “As the Lord passed along the public road of Dvaraka, His head was protected from the sunshine by a white umbrella. . . . His yellow garments and garlands of flowers made it appear as if a dark cloud were surrounded simultaneously by the sun, moon, lightning, and rainbows.” How is a magnificent rainbow possible when dark clouds surround the sun? As if anticipating this question, Srila Prabhupada answers:
The sun, moon, rainbow, and lightning do not appear in the sky simultaneously. When there is sun, the moonlight becomes insignificant, and if there are clouds and a rainbow, there is no manifestation of lightning. The Lord’s bodily hue is just like a new monsoon cloud. He is compared herein to the cloud. The white umbrella over His head is compared to the sun. The movement of the bunchhair fan of flukes [hair] is compared to the moon. The showers of flowers are compared to the stars. His yellow garments are compared to lightning. And the flower garlands on His chest are compared to a rainbow. So all these activities of the firmament, being impossible simultaneous factors, cannot be adjusted by comparison. The adjustment is possible only when we think of the inconceivable potency of the Lord. The Lord is all-powerful, and in His presence anything impossible can be made possible by His inconceivable energy. But the situation created at the time of His passing on the roads of Dvaraka was beautiful and could not be compared to anything besides the description of natural phenomena.
All laws are subservient to Him.
One Among Countless Stars
Given that mere reflections and refractions of sun rays create splendors like rainbows at certain conditions, fathom this: the sun is only one of the countless stars in the sky. By using thermal, electrical, and nuclear powerhouses, the scientific brain supplies heat, light, and energy to some extent, but Lord Krishna provides the whole planet with unlimited energy from just one sun. He says in the Bhagavad-gita (15.12), “The splendor of the sun, which dissipates the darkness of this whole world, comes from Me.” The light of the sun originally emanates from the brahmajyoti, the effulgence of the Lord.
Everything is ultimately an expansion of Krishna , and therefore there is no other object of meditation besides Krishna . A bhakti-yogi is fixed in devotional service at all times, and whatever he sees, such as the resplendent rainbows, contributes to his appreciation of Krishna , the Supreme Personality of Godhead, and meditation on Him. The exquisite beauty of rainbows and the precise reflections and refractions involved in their formation remind him of the Supreme Lord’s perfect design. Krishna is the source of all rainbows.
Scientists are accorded great acclaim for a few spaceships, while Krishna effortlessly creates gigantic planets and stars, and perfectly maintains them. He says in the Bhagavad-gita (15.13), gam avisya ca bhütani dharayamy aham ojasa: “I enter into each planet, and by My energy they stay in orbit.” The laws made by the supreme brain are perfect. The sun never rises in the west and never sets in the east, nor is the colorful rainbow seen when the sun is ahead of us.
Indeed, majestic rainbows remind us of the supreme inconceivable intelligence and the ability of the supreme scientist, Sri Krishna . Therefore, let us glorify the source of rainbows through the second stanza from Sri Vraja- Raja-Sutastakam (“Eight Prayers Glorifying the Son of the King of Vraja”):
bhru-visankita-vankima-sakrudhanum
mukha-candra-vinindita-kotividhum
mrdu-manda-suhasya-subhasyayutam
bhaja krishna -nidhim vraja-rajasutam
“He whose broadly bending eyebrows appear like arched rainbows, whose pure moonlike face belittles millions of moons, who is endowed with sweet gentle smiles and pleasant speech – just worship Krishna , the dark jewel, the son of the King of Vraja.”
Damodara Nityananda Dasa (Dr. Dipankar Deb) is a disciple of His Holiness Bhakti Vikasa Swami. He holds a Ph.D. degree in electrical engineering from the University of Virginia and is the author of an upcoming book, Science, Nescience and Perfect Design.