Constructing the ark

The ark was big, about the same size as a cross-Channel ferry with three decks, but no bow or stern. It was designed as a floating refuge rather than a conventional ship - not at all as depicted in children's story-books. One way of testing the authenticity of the Flood tradition is to ask whether the ark was seaworthy.

In 1994 a team from the Korea Research Institute of Ships and Ocean Engineering published a detailed study of its three most critical properties: how much it would pitch forwards and backwards, the extent to which it would yaw (spin around), and its liability to capsize. They concluded that the ark's dimensions would have given it optimal stability. Naval architect David Collins calculated it would have been more stable than modern ships, mainly because today the extra margin of stability is sacrificed for higher speed and greater manoeuvrability. Even in a 200-knot wind it would have been difficult to tip the ark more than a few degrees.

Was there enough room for every kind of animal?

Genesis states that Noah took on board a male and a female of every kind of land animal - in some cases seven pairs - and enough food for them. Since today there are millions of species, how could the ark have carried so many?

The answer depends on how many fundamentally different kinds of animal existed in the beginning. Since animals diversified enormously after the cataclysm, the number of original kinds would have been small, though we should also allow for some diversification before the cataclysm. To arrive at an estimate, we need to trace the evolutionary family trees back to the ancestors at the base of those trees.

Our current estimate is that all mammals, living and extinct, can be grouped into fewer than 50 original kinds. As we are still getting to grips with the amazing capacity of species to change form as they diversify, the actual number is likely to have been even smaller. Similarly there may have been fewer than 20 original kinds of bird and 20 kinds of reptile. With younger animals being taken in preference to older ones and the average size of vertebrates no bigger than a sheep, there would have been plenty of room.

There would also have been room for more than eight human beings if people had heeded the call to repent and come on board.