Rainbows, the Flood, and the Covenant
(Adapted from the author’s The Genesis Account. A theological, historical, and scientific commentary on Genesis 1–11, available at creation.com/s/10-2-606).

After the Flood, Noah and all the Ark’s human and animal passengers disembarked. Then God made the Noahic Covenant. Then, as the historical account reads, God provided a sign for His covenant with Noah’s family and all living creatures—the rainbow:
And God said, “This is the sign of the covenant that I make between me and you and every living creature that is with you, for all future generations: I have set my bow in the cloud, and it shall be a sign of the covenant between me and the earth. When I bring clouds over the earth and the bow is seen in the clouds, I will remember my covenant that is between me and you and every living creature of all flesh. And the waters shall never again become a flood to destroy all flesh. When the bow is in the clouds, I will see it and remember the everlasting covenant between God and every living creature of all flesh that is on the earth.” God said to Noah, “This is the sign of the covenant that I have established between me and all flesh that is on the earth.” (Genesis 9:12–17)
Coming from the sun shining through the dark clouds, the rainbow symbolized the heavenly pervading the earthly. And as it spans the horizon, it reminds man that God’s covenant is universal, as was the Flood that will never recur.1
Although the rainbow is a spectacular sight for man, the assurance we have that there will never be another global flood comes from God. He is the one who will ‘remember’ His covenant. Note that God ‘remembering’ doesn’t mean that he had previously forgotten; rather, it is an idiom meaning that the rainbow would signify that He is acting again on behalf of the Covenant beneficiaries, ensuring that no subsequent flood would become global.
Rainbows before the Flood?
The Noahic Covenant was certainly the first mention of the rainbow. But the Bible is silent on whether they had previously occurred. However, there are some considerations that suggest there would have been rainbows, which will be addressed in turn: the science of the rainbow, the natural laws that operated before and after the Flood, and God’s sovereign authority to ordain meanings to phenomena.
The science of the rainbow
Rainbows are the result of well-known physics. When light enters at an angle into a substance where it travels more slowly (like a prism),2 different wavelengths are bent differently. This effect is called dispersion. Since colour depends on wavelength, we see this as a band of different colours. The shorter wavelengths (violet and blue) are bent the most, the longer wavelengths (red and orange) are bent the least.

The great creationist physicist Sir Isaac Newton experimented on dispersion by glass prisms. His experiments demonstrated that colour is a property of the light itself; coloured objects don’t generate colour, they absorb or reflect light that is already coloured.3
Actually, the dispersion is continuous; we see coloured bands because of the design of our colour vision.4 Newton designated seven colours to the rainbow by analogy with the seven notes of the musical scale: red, orange, yellow, green, blue, indigo, and violet, hence the mnemonic initialism ROYGBIV. But there are different designations and numbers of colours. For example, I don’t see ‘indigo’, but sometimes see a small band of blue-green (also called ‘aqua’, ‘cyan’ or ‘turquoise’).5 Actually, the difference might be with the names we give colours—one author suggests:
A careful reading of Newton’s work indicates that the color he called indigo, we would normally call blue; his blue is then what we would name blue-green or cyan.6
Also, dispersion can be produced from water drops, including rain. The drops also reflect the light, so we normally see rainbows only if we are between the sun and the raindrops. The reflection also explains why the sequence seems reversed: violet on the inside and red on the outside. Yet we can also see smaller rainbows with mist and sea spray.
Natural laws did not change
God mainly used natural causes in the preservation of Noah and the animals e.g. Noah had to build a wooden Ark; the cause and rise of the Flood—fountains of the great deep plus 40 days of rain; and its abatement—a wind, and continents rising and ocean basins sinking. This suggests a continuity between ‘natural laws’ before and after the Flood.
There is simply no evidence from the biblical text that natural laws functioned so differently that dispersion of light would not have occurred before the Flood. Rather, what the text does say suggests that there was no difference in the natural laws. Also, natural laws are our description of God’s normal, repeatable ways of upholding His creation, while miracles are His extraordinary means.7 So if rainbows were not produced, we would need to deduce that God was actively preventing dispersion. There is not the slightest evidence in the text for this.
Applying a new meaning to an existing phenomenon
Calvin, commenting on “I have set my bow in the cloud” (9:13), said:
From these words certain eminent theologians have been induced to deny, that there was any rainbow before the deluge: which is frivolous. For the words of Moses do not signify, that a bow was then formed which did not previously exist; but that a mark was engraven upon it, which should give a sign of the divine favor towards men. … Hence it is not for us to contend with philosophers respecting the rainbow; for although its colors are the effect of natural causes, yet they act profanely who attempt to deprive God of the right and authority which he has over his creatures.8
There are other examples of existing materials or practices that God decreed to be a new sign. E.g., Jesus ordained the Lord’s Supper out of bread and wine. He declared that this was now to be a memorial to His sacrifice of His body and blood.

Related Articles
Further Reading
References and notes
- Delitzsch, Franz, cited in: Keil, C.F. and Delitzsch, F., Biblical Commentary on the Old Testament 1:154–155, 1857. Return to text.
- That is, has a higher refractive index (n), given by the formula c/v—the ratio of the speed of light in a vacuum to the speed in the material. Return to text.
- Newton, I., Opticks or a treatise of the reflections, refractions, inflections and colours of light, Royal Society, London, 1704. Return to text.
- See ‘Colour vision’, in Sarfati, J., By Design, pp. 29–31, CBP, 2008; creation.com/s/10-2-524. Return to text.
- Also, in my secular science work, I once used two cyan beams from an argon ion (Ar+) gas laser. Each laser line is a single frequency or pure colour by definition, in this case 488.0 nm and 514.5 nm. Sarfati, J.D. and Burns, G.R., The pressure, temperature and excitation frequency dependent Raman spectra; and infrared spectra of CuBrSe3 and CuISe3, Spectrochimica Acta Part A: Molecular Spectroscopy 50(12):2125–2136, November 1994 | doi:10.1016/0584-8539(94)00176-6. Return to text.
- Waldman, G., Introduction to light the physics of light, vision, and color, p. 193, 2002. Return to text.
- Sarfati, J., Miracles and science, creation.com/miracles, 1 September 2006. Return to text.
- Calvin, J., Genesis, p. 293, 1554. Return to text.
Readers’ comments
I back up the comment that you are putting this scientific theory before scripture. If we are to take on board your take, we will have to also go against a lot of commentators, theologians, and creationist scientists who have made sense in backing up the fact that a plain reading of the text is that there was no rain, and no RAINBOW (in the clouds; don't split hairs about some possible similar effect). Henry M. Morris was one example of someone who gave a very good scientific explanation of the pre-flood worldwide watering system that God had initially set up, to produce the mist, and there was obviously a lot of water up in the outer atmosphere waiting to rain down for 40 days and 40 nights continuously. (The Genesis Record, 1st published 1976)
This is obviously not a salvation matter, yet I believe that it is very important, because you seem to be suggesting that we take on a confusing argument here that essentially questions the plain meaning of the Scripture. My advice: hold this theory of yours lightly and put it down to an interesting discussion, taken seriously it is divisive and will be confusing to enquirers of the message behind the flood story.
The Genesis Record was very good for its time, but it’s now 42 years old—older than some of our speakers! That’s one reason that CMI published a more up-to-date commentary. Science has moved on, so while Scripture is non-negotiable, scientific models such as the canopy theory may well need modification or even abandonment, with new ideas to take their place.
It’s also worth noting that no biblical exegete before the 20th century saw a water vapour canopy taught in Scripture, which would be surprising if it were a direct teaching.
I believe in the canopy effect which supports a very lush green earth (before the flood) born out by the massive amount of fossil fuel that we are blessed with every day for oil, tires, plastics etc. etc. This would also have resulted in much higher oxygen content in the atmosphere than what we have today.
Some comments posted here suggest too much book learning and philosophical study and not enough faith in the wisdom and power of almighty God.
And from where did you get the idea about the canopy and what it would have done, higher oxygen content, fossil fuel production, and the synthesis of plastic and rubber? None of these are direct teachings of Scripture. So evidently they come from “too much book learning and philosophical study” ;)
Indeed we were not there at the time. But we have the Witness who was there. As shown in the article, He has revealed propositions from which we can logically deduce that the laws of science, aka God’s regular means of upholding His creation, were the same before, during, and after the Flood.
Agreed. I do not advocate vapor canopy theory, which is long outdated. I was referring to higher O₂ primarily, and possibly higher N₂ as well.
The evidence for higher oxygen fraction does not necessarily mean the atmosphere was thicker. But, given there is no source of Nitrogen in the Earth's crust or mantle, the N₂ could have been higher before the flood, but not lower.
O₂ is biologically active. So the balance of O₂, H₂O, and CO₂ is highly dependent on the amount of life and land area of the planet. If anything in the atmosphere changed from the Flood it was almost certainly in the area of O₂, H₂O, and CO₂.
But note, only a higher total atmospheric pressure would hold more H₂O vapour, which was necessary for your previous suggestion of preventing rainbows. Also, the links provided shows that the evidence for higher O₂ concentration in the past is equivocal, and that it may not have been as beneficial as claimed.
So, it is quite possible that in the pre-flood world the majority of the available water vapor was condensed out as dew each evening, which did not allow for the formation of clouds and rain which are necessary to form rainbows. But at night, they might have seen moonbows, as the full moon shone through the fog.
And after these were written, many secular scientists now think that earth’s atmosphere was much thinner than today’s, i.e. had a much lower pressure (Pease, R., Earth’s ancient atmosphere was half as thick as it is today, sciencemag.org, 9 May 2016 | doi:10.1126/science.aaf9981). I am not saying they are right either, but just pointing out that evidence for a thicker atmosphere is nowhere near as clearcut as many people think.
Perhaps someone could say why the “canopy effect” has fallen out of favor, because to me it is what Scripture indicates and it accounts for several situations including protection from damaging sun rays. Would a perfect creation permit sunburn and cancer? If God holds the atom together, He certainly could hold a ring of water around the earth. Colossians 1:17. The present is not always the key to the past.
In this case, we have the combination of something already existing in our diets, and something new added. With the rainbow, there was something already existing in the sky, and God gave it a new meaning.
Also, as I cited, nothing I said was contrary to conservative Christian teaching. Calvin said the same thing, and he was certainly not evolutionized—indeed, he was a biblical creationist!
I have also explained why the canopy theory has fallen out of favour, and one is that it would not have done what you claim. Water vapour is not a good protector against ultraviolet radiation, but is an excellent absorber of infrared. So we would have been both sunburned and cooked! And note also, Noah spend over a third of his life after the Flood, and still had the third longest recorded lifespan. So why wasn’t he affected by the supposedly greater sunburning? Note also, the perfect creation ceased after the Fall, while the antediluvians lived in a world where “painful toil” was necessary to survive. For more, see Flood models and biblical realism and the older Living for 900 years, a lay version of the even older Decreased lifespans: Have we been looking in the right place?.
One role of CMI is to equip Christians with up-to-date information.
This article was written when the ‘Canopy theory’ was still mainstream, but it still noted that it was still a model not a direct teaching of Scripture. And for the last 20 years or so, most ‘mainstream’ creationist organizations, including CMI, have advised against the canopy idea.
A quasi-continuation of this article was Biblical history and the role of science, differentiating between the correct ministerial role of science and the erroneous magisterial role. Applying to the issue at hand, there is the paper Flood models and biblical realism. So my commentary was hardly a sudden departure from creationist interpretation in this area, but reflected the widespread creationist consensus of quite a number of years.
In the paragraph above the heading Natural laws did not change there is a sentence implying that the colours of the bow are always in the same order inside to outside. That ignores the occasions where double bows can be seen concentric with each other, the colour sequence being reversed with respect to each other. The outer bow is usually partial probably because the right conditions have to exist over a greater area for it to become visible.
Also, small droplets are harder to form than large ones, because the Laplace pressure is inversely proportional to radius. A tiny droplet would also presumably act as a nucleation site. Finally, something could not even be called a ‘mist’ unless the particles were large enough to interact with light.
In the article, I documented other signs that were not new effects, but new meanings attached to those effects.
We still wrestle with the idea that the speed of light is a constant. Nature abhors constants. Dozens of measurements of the speed of light indicate that the speed of light is slowing down. The only one that does not is the atomic clock based test. Until now people have thought that it was simply the most accurate. Theoretical physicists now state that if there is such a force that could slow down the speed of light then it would proportionally slow down the speed of radioactive decay. This means the the atomic clock is slowing down at the same rate that the speed of light is, making it look like a constant.
Our grasp of God is far more limited still. I had a philosophy student ask me, “If your God is so strong, can He create a rock so big He couldn’t move it?” I told him, “Your question only shows your ignorance of God. If God were to create a rock bigger than the known universe, and then decide that He wanted it to move … it would move on its own.”
God is the author of the universe. If He decided to change the laws of physics, He can do that.
There are many things that we will not be able to know while we are here in this world. It can be fun to speculate, just never make the mistake of thinking that God is limited by the laws of science.
I am not aware of measurements showing that the speed of light is decreasing. We have written on this before in Speed of light slowing down after all? Famous physicist makes headlines.
Yes of course He can. But this is not the issue at hand. My article documented from the Genesis record that He did not.
Overall, our position is best expressed in Hidden messages in Scripture?
Also too is that life expectancy drastically shortened after the Flood indicates that the prior environment likely was such that life could live longer.
Now this is a problem for long-age views, because none of them would hold that there was no rain before man.
The other inference you made also does not logically follow.
As for the change in lifespans, claims that they were caused by a less hospitable environment founder on the data for Noah. He lived over a third of his life in the supposedly much worst post-Flood world, but had the third longest recorded lifespan in history: 950 years. I explain more in my article “Why don’t we live as long as Methuselah?” in Creation 40(3), also from my commentary.
Regards,
In Christ
Roseanne
However, I still think it’s possible that the pre-Flood world was watered by dew, as is implied by Genesis 2:6. And it's interesting to note that in Genesis 8:22, God promises ‘While the earth remains, seedtime and harvest, cold and heat, summer and winter, day and night, shall not cease’, implying a radical change in the earth’s natural dynamics—e.g. a tilt in its axis, causing a seasonal climate.
We also accept that the animals, now being legitimized as food for man, would behave differently—with fear and dread—certainly in the terrestrial mammals—so God was certainly able to re-calibrate the existing natural order, as He obviously drastically did, after the Fall.
So, whilst I understand your conservative view (i.e.in line with physical constants), I do not necessarily accept that rainbows were among the ‘all things that have continued from the beginning’.
And earlier in that commentary, I pointed out that the luminaries were given for several things on Day 4 of Creation Week, including seasons. So if seasons existed from Day 4, then God must have created the earth with an axial tilt. An impact would have had very little effect on the tilt; the commentary goes through points explained earlier in When did evil begin, and is retrograde planet motion still a good argument?
Comments are automatically closed 14 days after publication.