Fred Von Flanningan (I just made him up) was a logical kind of thinker. He was an expert on pre-flood times. When people talked about monoliths built with huge stones, or about giant birds and dinosaurs of long ago, he had a theory that helped to explain them.
For instance, when it is asked, "What happened to big, heavy dinosaurs? How could a heavy bird-like creature such as a Pterodactyl fly?" Or "How were the pyramids built?" Fred turned to his simplistic, but logical reasoning. He asked, "What if the Earth used to rotate faster than it did after the flood?"
This is not so fantastic an idea as it might first seem. When I took a college course on astronomy, the professor told us of an interesting fact. In the spring, the Earth's rotation slows down. It regains speed in the Fall. He figured that most of the deciduous trees are in the northern hemisphere where Winter causes their leaves to fall. In the Spring, when their leaves return, the elevated weight slows the Earth a little, like a spinning ice skater extending her arms, or pulling them in to vary her speed of rotation. The weight of leaves and rising sap is sufficient to explain the change in the Earth's rotational speed.
What if the pre-flood Earth spun faster? The effect would make gravity seem less. The waters of the flood were much greater than leaves and sap. Add in, that giants (look them up to see their skeletons) with less gravity could more easily lift heavy blocks.
What about the Pterodactyls? A denser and more oxygen rich atmosphere--which some experts posit--coupled with less gravity, could give them the ability to fly. Heavy dinosaurs could live under the same conditions.
That is Von Flanningan's theory, what do you think of it?