To many people the Bible is just a book of mythology; a nice collection of stories useful for moral teaching. In a world where science is revered as the arbiter of truth the Bible’s claims can seem unbelievable. How could someone believe in a book that claims the world was created in seven days? Or that all living creatures were destroyed by forty days of rain? Or that a sea could be parted to allow one million people to walk through on dry land, before returning to wash away a pursuing army of Egyptians? To those who have learned about the history of the world from scientists and statisticians, the Bible’s stories may appear more like myth than reality.

But what happens when we take these seemingly fantastic stories and claims made by the Bible and analyze them by the very science they appear to contradict? We will consider the scenario the Bible describes before, during and after the alleged Flood event, and examine from a scientific perspective the credibility of the details of the Biblical account.

Problems with the Biblical Account of the Flood
Please read Genesis chapters 5-9. Within the story there are three items that contradict contemporary experience (and therefore overstretch the beliefs of many):

  • 40 days of rain flooded the Earth above the tops of the mountains (Genesis 7:6-24). How can rainfall put the whole earth underwater?
  • The average antediluvian (pre-Flood) lifespan is 910 years (Genesis 5:3-32). How can people have lived this abnormally long?
  • The rainbow is witnessed for the first time after the Flood (Genesis 9:12-16). Why would optical laws change, if indeed rainbows were not visible before the Flood?

How can rainfall put the whole earth under water?
We can create a model (shown in Figure 1), which is based directly on the scriptural description of the world prior to the Flood (Fig 1a) and the observable situation today (Fig 1c).

The Biblical account of creation claims:

And God said, “Let there be an expanse between the waters to separate water from water.” So God made the expanse and separated the water under the expanse from the water above it. And it was so. (Genesis 1:6-7)

Figure 1a reflects this description: a shell of water fully encircling the Earth. The Biblical description of the “water above” cannot be explained as the clouds because the sky is described as the divide between the two layers of water. The “water above” needs to be a shell above the expanse of the sky. How much water was in this shell? That cannot be known. Therefore we arbitrarily split the known quantity of the world’s water into two, and suppose half above the divide, and half beneath. Half of the Earth’s current water supply suspended at the outer edge of the ionosphere (i.e. “top of the sky”) would form a shell of H2O ~ 5 km (3 miles) thick weighing ~ 7x1020 kg.

Figure 1: Three stages of the Flood: a) Antediluvian (before the Flood), b) The Flood event, c) Postdiluvian (after)
This provides the foundation for answering that first question: how could the earth be flooded by water coming from the sky? The Genesis account describes a catastrophe created by 40 days of rain. The quantity of water suspended above the atmosphere under the Biblically described conditions provides the perfect answer as the mechanism for the global Flood. If this water layer became astronomically unstable and collapsed it would temporarily submerge the continental plates—not by volume of water alone, but by the accumulated pressure the freefall collapse would cause (Figure 1b) ~ 2000 pounds per square inch (psi) on the whole Earth’s surface. It is also calculable that a global pressure of 2000 psi would rupture the Earth’s crust. Note however that this pressure will not build up on objects where the water runs off, as for example the Ark, or any object on the Earth’s surface. It is only on the Earth itself, from which the water cannot ‘run off,’ that this cumulative pressure applies. The effect of this pressure on the earth’s crust by the collapse of the aqueous shell is consistent with the scriptural description that “all the fountains of the great deep [were] broken up,” (Genesis 7:11). So far, the scriptural model of the earth before the Flood and the consequences of the release of water from the atmosphere are consistent with what science would expect to happen given the conditions described in the Biblical record.

But other questions remain. If it can be proven that the amount and pressure of the water were enough to Flood the earth and rupture the earth’s crust, how then is the water removed so that the land becomes above water again? It is important to understand that the continents are not fixed at radii from the centre of the Earth, but that the continents exist in more complex relationship with the molten magma beneath them. The collapse of such a water shell from an unstable orbit, as described in the Flood account, would indeed submerge the continents and “break up the foundations of the deep”. But after this dramatic event a new equilibrium would be established on the earth. (Figure 1c) Just as a sponge can be submerged in a bath of water by pouring water on top of it but will rise to its equilibrium floating depth once the pouring stops - without removing the additional water - the earth’s crust would be submerged by the Flood water and then rise to its equilibrium floating depth without the removal of the water that fell from above.

Using our modern understanding of the earth’s structure, we can understand how the Flood story can be very real indeed—the scenario described by the Bible thousands of years ago could have scientifically occurred. What is particularly interesting is that our scientific understanding of the sideline details— for example the body of water required to be present above the Earth and the collapse of that water “breaking up the foundations” of the Earth’s crust—have only become available to us within the last century. Yet evidence of such eventualities has existed within the Bible for much longer (Genesis 1:6-7 & 7:11). It is not possible that the writer of the Genesis account would have understood the scientific principles at work on Earth when recording the Biblical account of the Flood, nevertheless modern science does indeed lend credibility to the Bible’s claims about the Flood.

How could people have lived for an average of 910 years?
An answer to this question can be found when we recognize that the Bible does not report an extraordinary long life, but an extraordinarily slow rate of development—a subtle but important difference. The Bible is not depicting a state in which men age at the same rate they do today, becoming severely limited in all physical faculty at 100 years and then living for another 800 years. Rather it describes the aging process as occurring much more slowly.

Figure 2: Biblical claims of total age of successive generations from Adam (), and age of father when first child was born ().

Consider Figure 2, which shows the age at which each man named in the Bible living before the Flood bears his first child. Figure 2 shows that each man bore his first child on average one seventh (14%) through his life. This is approximately the same ratio as exists today. Humans are capable of bearing children at about 14% of their total life expectancy (this percentage is typically greatly extended by socio-economic factors in Western civilization). Using a contemporary age of 13 years as the earliest childbearing age, the claimed life spans before the Flood can be calculated to a contemporary equivalent of ~95 years. Thus the great difference between the antediluvian (pre-Flood) lifespan, claimed by the Bible, and today’s lifespan is best expressed in terms of degeneration rate rather than lifespan. Humans aged much more slowly before the Flood than they do today, resulting much longer lives.

Having understood this, we are in a position to approach the second problem surrounding the Biblical account of the Flood: how could humans live for so long? With the model scripture presents (Figure 1) we understand that before the Flood, there was an aqueous layer around the Earth. This necessarily results in a significantly lower radiation density at the Earth’s surface (in certain key parts of the electromagnetic spectrum), and we know that the life span of a cell is inversely proportional to the intensity of critical frequencies of the radiation density to which it is exposed. While even modern science is not sufficiently equipped to attempt quantitative calculations from such a drastically different ecological arrangement, particularly on life forms as complex and macroscopic as humans, we can at least conclude that the effect of dramatically increased radiation density, as would have occurred after the Flood because of the removal of the aqueous shell, would significantly reduce the cellular lifespan through increased degeneration rate and thus logically reduce human life spans.

Once again, even with all the skepticism we can muster about the scriptural record, we must honestly acknowledge that the Bible does indeed describe a dramatic decrease in lifespan (and proportional decrease in child-bearing age) directly after the alleged Flood event. This decrease is exponential with successive generation, and is shown in Figure 3.

Figure 3: Biblical reports of lifespan in successive generations from Adam.

Consider Figure 3 carefully. The Biblical record reveals that lifespan before the Flood was stable: man’s lifespan was in equilibrium with his environment. The catastrophic event of the Flood creates a wholly new ecosystem where the degeneration rate, and hence lifespan, of man is fundamentally affected and responds to find a new equilibrium. This is exactly what science predicts should have happened if the aqueous shell of water was removed, does happen! The Bible reports a sharp decrease in lifespan after the Flood event. What is of particular importance is that while the modern scientist would be confident that the collapse of a shell of water around the Earth would result in all of these trends (even if we do not have enough information from either science or from the Bible to approach a quantitative analysis), this was certainly not known at the time the Bible was written.

Why would the laws of science change such that rainbows only appeared after the Flood?
Finally, the third and final problem the Biblical account of the Flood raises: how is it possible that no rainbow was ever witnessed before the Flood? The development of optical science (Table 1), and in particular the work of Isaac Newton, lends valuable insight into this issue. In a famous experiment in 1666 Newton used a triangular glass prism to split sunlight into the colors of the rainbow. Newton demonstrated that for this effect to be observed, parallel incident beams of light were required to pass through a transparent medium with a significantly different refractive index than that of air. Newton was able to use sunlight for his experiment, with appropriate shutters at his window, because the Sun is 1.49 x 108 km (93 million miles) distant and therefore the small percentage of photons that intersect the Earth are parallel to a good approximation.

This discovery significantly impacts our understanding of the conditions the Bible describes prior to the Flood. In the antediluvian regime described in Genesis 1 (Figure 1a) aqueous/frozen water particles around the Earth would disrupt the parallel travel of the solar rays. Thus no rainbow would be witnessed even at coincident times of sunshine and rain (Figure 4a). After the Flood however, because of the removal of the aqueous shell, the coincidence of parallel sunlight and rain would necessarily cause the existence of a rainbow, as we witness today (Figure 4b).

Table 1: Brief history of the development of optical science
Date Scientist Discovery in Optics
BC 300 Euclid Light can be reflected by surfaces
130 AD Ptolemy
Light can be refracted in water
1600 Galileo Development of astronomical telescope
1621-1637 Snell
General theory of refraction
1666 Newton Refraction of white light into colors
1670 Huyghens Polarization and wave theory
1676 Romer Speed of light is finite
1801 Young Principle of optical interference
1870 Maxwell Light is a wave propagating through the luminiferous ether
1880-1905 Micholson
Disproved existence of the luminiferous ether
1905-1920 Planck
Wave/particle duality
The photon
Photon’s self-propagation through free space
Quantum Mechanics

What is compelling about this evidence is the chronology of the Bible’s claims compared to scientific discovery. Even if we are to regard the Bible as a cunning hoax, its existence can be dated confidently to the early centuries AD. This book claims that there were no rainbows before the Flood but rainbows were immediately visible afterwards. With the details that the Bible describes of the Flood this is exactly what the modern scientist would anticipate! Yet this scenario, like those in questions 1 and 2, could not have been anticipated prior to the work of Newton!

There is one point more to consider. The Bible not only describes the appearance of the rainbow, but also claims to know the reason for its introduction. God gave the rainbow, claims the Bible, as a guarantee that He would never cause a global Flood on the Earth to destroy everything.

“And I have set my rainbow in the clouds, and it will be the sign of the covenant between me and the earth. Whenever I bring clouds over the earth and the rainbow appears in the clouds, I will remember my covenant between me and you and all living creatures of every kind. Never again will the waters become a Flood to destroy all life.” (Genesis 9:13-15)

Figure 4: a) Antediluvian coincidence of sunshine and rain: no rainbow as solar rays not parallel b) Postdiluvian coincidence of sunshine and rain necessarily produces a rainbow
It is extraordinary that this claim is also now wholly deductive from scientific observation! (Figure 4) The sight of a rainbow is a guarantee that the illuminating solar rays are parallel, which in turn guarantees they are not passing through a body of water above the Earth. The absence of a body of water above the Earth is reasonable evidence that there will not be another global Flood. And God promised all of these things in the Bible, written long before the science was in place to deduce it.

Assessment of the Claims and Facts
Our initial premise was that if one could scientifically analyze the most outlandish and “unbelievable” story of the entire Bible and demonstrate a plausibility, we would be challenged to stop and reconsider the Bible’s claim to be the word of God. For those skeptical about the veracity of the Bible, let’s assume that the Bible is NOT the inspired Word of God and came about by uninspired human authorship. We can then make valued judgment of the Bible’s claims in the light of the science considered above.

Assuming the Bible is false: if there were once a layer of water above the skies that collapsed, as the Bible describes, what implications would be scientifically anticipated for scenarios before, during and after the collapse of such a layer?

Scientific Fact
No rainbows will be observed while the water layer persists because the diffusion of the sun’s rays will not instigate the macroscopic polychromatic refraction effect we recognize as a rainbow. This has only been known since the pioneering work of Isaac Newton in 1666.

Conclusion: It must therefore be a complete coincidence that the Bible, written long before the work of Newton, describes this exact scenario.

Scientific Fact
Were such a layer of water to prove astronomically unstable, its collapse to Earth would result in a global Flood. It would not require a depth of water greater than the height of existing mountains to submerge the continents because they would be suppressed by the water’s weight. For the same reason, such a submersion would be temporary because the continental plates would re-emerge as a new equilibrium was established.

Conclusion: Coincidentally the Bible also describes such an event where continents are completely submerged by a deluge of water and then subsequently re-emerge without any additional mechanism intervening to remove the water.

Scientific Fact
Subsequently increased radiation density would have a dramatic and accelerating effect on rates of cellular development and decay; thus diminishing lifespans. The reduced lifespan would be effective immediately subsequent to the Flood, but eventually stabilize to an equilibrium value.

Conclusion: It must, therefore, be a further extraordinary coincidence that the Bible also describes this exact trend: where there is first a stable lifespan limit, that this lifespan limit decays, that the onset of the decay is exactly coincident with the Flood, and that it eventually reaches a new and significantly lower limit.

Scientific Fact
After the collapse of the water layer rainbows will necessarily result upon future coincidence of sunshine and rain, as is outlined from the work of Newton and unknown prior to 1666. The rainbow’s presence scientifically guarantees that there is no further water layer above the Earth and therefore no reasonable possibility of a global Flood today.

Conclusion: The Bible records that the rainbow is witnessed for the first time directly after the Flood. It also details that the rainbow is given by God to guarantee no future repetition of a global Flood. This also must be considered as a complete and bizarre coincidence.

The Challenge
The number of extraordinary and unsupported coincidences that are required to be believed for the Bible to be false, are a far greater burden on credulity than can be considered reasonable. Given that humans did not have the scientific knowledge to verify or predict the outcomes of a global Flood on the Earth until recently, one must ponder just how the Biblical writers could have known exactly what to write to make their account credible by the science that is now known, but was then unknown. The scientific credibility of what seems to be the most “unbelievable” and fantastic story of the Bible challenges us to reconsider the Bible’s claim to be the Word of God. There is information in the Biblical account that could not have been known by human sources at the time of its writing. If what seemed to be the most outlandish claim of the Bible can be shown to be scientifically possible, we must conclude that it is indeed possible that the Bible’s other claims are also true. There is just too much at stake not to take a closer look at what the Bible teaches. If, as science has corroborated, God was willing to save eight people from a global Flood in order to bring about his will for the earth, what more could He be offering you? Why not take a chance, read this book that claims to be the word of God, and find out?


Even if the Flood can be shown to be scientifically plausible, why would I then trust all of the Bible is true?

I’m not a scientist. Is there any historical evidence that the Bible is true?