This is a topic I just have to comment on, given the recent movie Noah and some comments I have heard from family members. I find it astounding that an educated, intelligent person, especially one with a degree in engineering or a hard science, could believe that the story of Noah and the Flood in Genesis is a literal, historical account. The only evidence in favor of it is an ancient legend recounted in the Bible and the story of Gilgamesh.  Everything else argues against it. This is not a question of just one or two anomalies; the story falls to pieces pretty much however you approach it.

Others have already gone over this ground in detail, so I’ll just link to one of these articles—The Impossible Voyage of Noah’s Ark—and mention a few obvious problems that occur to me.

First, let’s talk prior plausibility.

How plausible is it that a construction crew of at most 8 people could build a wooden vessel much larger than any ever constructed in the 4500 years since, using pre-industrial, Bronze Age technology?

Assuming an 18-inch cubit, the Bible claims that the ark measured 450 feet long, 75 feet wide, and 45 feet high, that it was made out of “gopher wood,” and that it was sealed with pitch, presumably to keep it water tight. The ark as described in the Bible is essentially a barge, so I did a quick web search on the largest wooden ships ever built, and the closest thing I could find to the claimed size of Noah’s ark was the Pretoria, a huge barge built in 1900.

At the time of its construction, the Pretoria was the largest wooden ship that had ever been built, and is nearly the largest wooden ship of any kind ever built. Nevertheless, the Pretoria measured considerably smaller than the claimed dimensions of Noah’s ark: 338 feet long, 44 feet wide wide, and 23 feet in depth, or just under 1/4 the claimed total volume for Noah’s ark. Like other such large wooden ships, the Pretoria’s frame and hull required strengthening with steel plates and bands, along with a steam engine to pump out the water that leaked in. According to the 1918 book How Wooden Ships Are Built (by Harvey Cole Estep), “If current practice is any guide, it may safely be stated that steel reinforcement is necessary for hulls over 275 feet in length and exceeding, say, 3500 tons dead weight.”

Then there’s the question of where all that water came from, and where it went. A simple calculation shows that it would require about an additional 4.5 billion cubic kilometers of water to cover the whole Earth up to the top of Mount Everest, or nearly 3-1/2 times the current total volume of the world’s oceans. If you want to hypothesize that somehow such high mountains didn’t exist prior to the Flood, and were raised up afterwards, then you have several severe problems:

• Every time you add a new ad hoc addendum to your hypothesis to patch up a hole in the story, this as a logical necessity lowers the prior probability of the overall scenario.
• The best geological evidence says that the Himalayas are about 50 million years old. They were definitely around at the time of the presumed Flood.
• If you want to argue, against the geologic evidence, that somehow the Himalayas weren’t raised up until after 2500 B.C., consider the energies involved! If you want to raise up the Himalayas in at most a few hundred years, instead over 50 million years, you are talking continual, massive earthquakes for that entire period, and I’m guessing that the heat produced would melt a substantial portion of the Earth’s crust.

Second, let’s consider expected consequences.

An obvious one is that archaeologists and paleontologists should be finding a very large number of scattered human and other animal skeletons all dating to the same time period of about 2500 B.C. Needless to say, they have found nothing like this.

There should be obvious signs in the geologic record of such a massive cataclysm, evidence that can be dated to about 4500 years ago. No such evidence exists.

The Bronze Age spans the years from 3300 B.C. to 1200 B.C. in the near East. See, for example, the Bronze Age article in the Ancient HIstory Encyclopedia. Do archaeologists find the civilizations of that era suddenly disappearing around 2500 B.C.? No, they do not.

Some fish live only in salt water, others only in fresh water. The flood described in the Bible would have either killed all of the salt-water fish (if the flood waters were fresh) or killed all of the fresh-water fish (if the flood waters were salty) or both (if the flood waters were of intermediate salinity).

What happens when you reduce an entire species down to a very small breeding population? Usually, it dies out—see the notion of a minimum viable population. But if the species avoids that fate, you get something like the cheetahs: an entire species whose members are all virtually identical genetic copies of each other. A world in which the Biblical Flood had really occurred would look very different from ours. Every animal species would consist entirely of near-identical duplicates. There would be no racial strife among humans, because we would all look nearly as alike as identical twins.

I’ve just scratched the surface here, without hardly trying. Anyone who actually sits down and thinks about it, and does a bit of honest research will have no trouble finding many more problems with the whole Flood story.