I discussed the logic (or lack of logic) in the Garden of Eden story in recent post. The story of Noah and the flood is another fascinating tale from this period and from the same sources.
Let me again address the question many are probably asking: given that this is just an ancient myth, why evaluate it as if it’s history (which I will be doing)? Because for 60 percent of Americans it is literally, word-for-word true. For Protestants, that figure is 73 percent. For Evangelicals, it’s 87 percent.
Prior flood stories
Robert Price in The Reason-Driven Life (pages 102–106) gives a summary of what came before.

[The Noah flood story] is a derivative version of demonstrably much older flood epics from the same area, including the Gilgamesh epic [Sumerian], the Atrahasis epic [Akkadian], the story of Xisuthros [Sumerian], and that of Deucalion and Pyrrha [Greek], all of whom survived the world-devastating flood by setting sail in a protective ark, most of them bringing the animals along for the ride. We find all the familiar details: The decision of the gods to flood the world for some offense committed by the human race, the stipulated dimensions of the ark, the provision for the animals, the onset of the rains, the number of days the flood lasted, the naming of the spot the ark came to rest, the sending forth of birds to find dry ground, the emergence of the refugees, their sacrifice, and the promise of the gods never to doom the world thusly ever again. It’s all there, at least most of it in most versions.

Yes, just because there were prior flood stories from that region doesn’t mean that the Noah story didn’t actually happen. And yes, just because the Sumerian cosmology both preceded Genesis and is the same as that described in Genesis—it water pours in from below and above (see Gen. 7:11)—doesn’t mean that the Genesis account was copied.
But in both cases, that’s certainly an enormous clue pointing to myth.
Contradictions
As with the two Genesis creation stories—six days vs. Garden of Eden—a flood story from the older J source (about 950 BCE) is combined with one from the P source (500 BCE) to make an unhappy compromise. (I discuss this Documentary Hypothesis and the Old Testament’s different sources here.)
The clumsy intermingling of the two stories can be seen, for example, in Genesis 8. The first five verses (the P account) tell about the water receding, the ark coming to rest on Ararat, and land becoming visible. The next seven verses (from J) make clear that land is not yet visible when Noah sent out birds to check for land, but “there was water over all the surface of the earth.”
The P source says that Noah brought just one pair of all animals (Gen. 6:19–20), while the J source says that he also brought seven pairs of all birds and kosher (“clean”) animals (7:2–3).
Why not keep pick one story to keep? According to Price, these two sources each had their partisans, so each had to be preserved. Better to merge them, however imprecisely, than to drop a beloved story element.
Story problems
It’s fun to compare the Noah story with science and history as we know it. Here are some of the problems that I’ve come across..

• The ark was 137 meters long, making it the largest wooden ship ever built. It would’ve required tens of thousands of big trees. Where did the wood come from? Could four men (Noah and his sons) have built such a craft by hand in less than 100 years?
• Consider how the square-cube law applies to the ark (discussed more thoroughly at Skeptoid). When you double the size of a ship, you double it in three dimensions. That’s also true for every piece of timber. Take a beam, 6 feet long, with a 4-inch-by-4-inch cross section. Now double it to 12’×8″×8″. The volume has gone up 8-fold, but the cross section has only increased by a factor of 4. It’s 8 times heavier but only 4 times stronger. This means that if you take a small boat and double every dimension, you have a much more fragile boat. To make it seaworthy, you’d have to use much thicker timber. How much cargo space would’ve been available given the massive beams the ark would’ve needed?
• What did the carnivores eat? There were a few extra kosher animals and birds for sacrificing, but what’s left for the lions and tigers and bears? What’s left for Noah and his family?
• What did the herbivores eat? Hay could store well, but what about the hummingbirds that drink nectar and bats that eat fruit? Flowers and fruit probably wouldn’t last for the many months of the journey. Did Noah’s sons collect fresh Chinese bamboo for the pandas?
• What did the insects eat? Biologists today would probably be unable to provide the right kind of food and living environments to ensure 100% survival for all known insects, but we’re to imagine that Noah and his sons had no problem?
• How did the fish survive? With the earth covered by a single body of water, which was likely turbulent and muddy in parts from the violent flow of water, the freshwater and the saltwater fish couldn’t have both been happy.
• How did animals travel from far-away places and then get back home afterwards? How did the penguins and polar bears get to Mesopotamia and stay comfortably cool during the trip? How did the kangaroos and koalas get to Australia?
• What did the carnivores eat after they were released from the Ark? Remember that eating even a single rabbit or zebra would’ve made that species extinct.
• Could all of today’s plants have survived months of immersion in salt water to recolonize the land?
• Some Bible literalists try to bypass the problem of finding space on the ark for millions of species by arguing that by “kinds,” the Bible isn’t referring to species but genera (the next-higher taxonomic level). Creationist Ken Ham seems to think that “kinds” were more like biological orders. But this forces them to imagine rapid speciation in the 6000 years after the flood, which is hard for the evolution deniers among them to do.

And let’s simply bypass the problem that geology tells us that there was no global flood.
Of course, God could’ve solved any of these problems with a miracle, but then why tell the story as if Noah and his family did everything? Why not just have God poof into existence a new world with everyone painlessly dead except Noah and his family? Because it’s just a story written with no concern about modern science.
Concluded in part 2.

If you pray for rain long enough, it eventually does fall. 
If you pray for floodwaters to abate, they eventually do. 
The same happens in the absence of prayers. 
— Steve Allen

(This is an update of a post that originally appeared 7/2/13.)
Photo credit: Amazon