The last of the three posts goes where it naturally weaves a path – http://malagabay.wordpress.com/2013/06/16/the-inflating-earth-4-gravity/ …. and leads from the equatorial bulge to the question of gravity. For this he goes to www.dinox.org which I mentioned a couple of days ago, the web site of Stephen Hurrell (dinosaurs and the expanding earth) – so you can have two bites of the same cherry.
Hurrell claims that gravity is a limiting factor for the size of life which harks back to a book published in 1917 by D'Arcy Wentworth Thompson, On Growth and Form. One theme in this book is that biologists in the 19th century over emphasized evolution as the fundamental determinant of the form and structure of living organisms and under emphasized the role of physical Laws and physical mechanics. A few days ago we learned that Einstein and Newton were not mechanical and now we find somebody suggesting Darwin's Origin of Species lacked physical mechanics. D'Arcy Wentworth Thompson appears to be an interesting fellow (see the Wikipedia entry) . He advocated structuralism as an alternative to survival of the fittest in governing the form of species. He pointed out many examples of correlations between biological form and mechanical phenomena, such as the similarity in form of jellyfish and the forms of drops of liquid falling into a viscuous fluid, or between the internal supporting structures in the hollow bones of birds and well known engineering truss designs. Hurrell beganb with the realisation large dinosaurs appear to be dynamically similar to smaller animals alive today. He then looked at leg bone strength, ligament strength and blood pressure – in order to trace a connection with gravity. The theory is that gravity at the time of the dinosaurs can be estimated from the relative scale of dynamically similar ancient and modern life forms. Hurrell, it should be noted, follows the mainstream Nerwtonian concept in that gravity is associated with Mass. This leads him to conclude the Earth has been expanding – but for the wrong reasons (in the view of Tim Cullen). He says there is no evidence to suggest the required level of 'increasing mass' as in Newtonian gravity model and yet Hurrell has presented obversational evidence that surface gravity is determined by radius – not mass (see also http://malagabay.wordpress.com/2013/02/20/newtonian-reality-check/
At this point we are getting into a debate that involves some of the bedrock of western science – which may well cause some readers minds to snap shut. Let's wait for the sequel.