Noah's Ark

Of all the stories in the Bible, Noah's Ark possibly poses the most scientific concerns. Where did all that water come from? Where did it go? Why are there records of civilizations both before and after this time, and why don't they record this event? Each of these questions is complex enough that they deserve their own posts. Here, I address only one of these issues. Could Noah have possibly fit two of each animal (seven, in some cases) on the ark? There had to be enough room to store enough food to last Noah and his family (8 individuals), plus the animals, at least a year and maybe more, depending on how long it took for vegetation to grow back. That’s a lot of food! What about drinking water? Is it realistic to believe that Noah’s boat was big enough to store all of these animals and all of this food and water for over a year?

How big was the Ark?

The size of the Ark is described in Genesis 6:15. 300 cubits long, 50 cubits wide and 30 cubits high. A cubit is the length of the forearm from the elbow to the longest finger. In fact, the term “cubit” comes from the Latin word “cubitum” which means “elbow.” Since everybody’s arms are different lengths, this unit is a little vague, but scholars generally agree that it represents somewhere between 17 and 22 inches (43-56 centimeters). I'm going to use the ancient Egyptian cubit, though, since it is known to have been 21.888 inches, and falls within the range of the Hebrew cubit. Therefore,

300 (# of cubits) x 22 in. = 6,600
50 x 22 in. = 1,100
30 x 22 in. = 660

6,600/12 (inches) = 550 ft.
1100/12 = 91.7 ft.
660/12 = 55 ft.

So Noah's Ark could have been up to 550 feet long, 91.7 feet wide and 55 feet high. That means that the total volume of the Ark was about 2,773,925 cubic feet. The Ark was not hollow, though, so the volume is not all storage space. Gen. 6:14-16 say that there were three floors with several rooms. A little more than half (54.75%) of the 2,773,925 cubic feet could store 125,000 sheep-sized animals, leaving over 1.5 million cubic feet of free space. John Woodmorappe, author of the definitive Noah's Ark: A Feasibility Study, estimated that only about 15% of the animals on the ark would have been larger than a sheep, making sheep a fair way to judge the number of animals that could fit.

How many animals were there?

So how many animals were on the Ark? There are somewhere between 3 and 30 million species of animal in the world.

Animals: estimated 3-30 million species

Invertebrates: 97% of all known species

--Sponges: 10,000 species

--Cnidarians: 8,000-9,000 species
--Molluscs: 100,000 species
--Platyhelminths: 13,000 species
--Nematodes: 20,000+ species
--Annelida: 12,000 species

Arthropods
--Crustaceans: 40,000 species
--Insects: 1-30 million+ species
--Arachnids: 75,500 species

Vertebrates: 3% of all known species
--Reptiles: 7,984 species
--Amphibians: 5,400 species
--Birds: 9,000-10,000 species
--Mammals: 4,475-5,000 species
--Ray-Finned Fishes: 23,500 species

However, not all of these would need to be kept on the Ark. Sponges, molluscs, many crustaceans and certain members of every other major group could have survived the flood off the Ark. Not even all of the birds would have needed to be held on the Ark, and many who did would not have required constant housing. The leading systematic biologist, Ernst Mayr, gives the number as 17,600. Allowing for two of each species on the ark, plus seven of the few so-called “clean” kinds of animals, plus a reasonable increment for known extinct species, it is obvious that not more than, say, 50,000 animals were on the ark” (Morris, 1987).

Some say that there were as many as 25,000 kinds of animals represented on the ark. This is a high-end estimation. With two of each kind and seven of some, the number of animals would exceed 50,000, though not by very much, relatively speaking. Regardless, whether there were 16,000 or 25,000 kinds of animals, even with two of each and seven of some, the number would have fallen well below the 125,000 animal limit which already had taken into account space needed for food and supplies.

Conclusion

Speaking only of the size and capacity of the Ark to carry a certain number of animals, it is obvious that at least this part of the story is not only plausible, but but entirely reasonable, assuming the dimensions given in Genesis are accurate. Again, we are not discussing how the animals got there or why they didn't eat each other, etc. These issues are problematic enough that they deserve their own posts, but there is no good argument against the carrying capacity of the Ark.