Firstly, let me apologise for the lack of posts on the blog recently. Unfortunately, a bout of chronic illness has altered my priorities, although I'll try to keep posting, if anyone's reading. Third Stone From The Sun With apologies to Jimi Hendrix, I'm focusing upon Earth and the place of the human species within the biosphere. There are roughly seven billion of us around and this number is projected to grow wildly by the end of the century. Put simply, that's a lot. We live on a blue-green marble, with the emphasis upon the blue bit, i.e. water. One of the stand out things about humans is being both primates and one of the Great Apes, we're remarkably good at dealing with and surviving in water. Unlike most primates and more like cetaceans (whales and dolphins) we exhibit the 'diving reaction'. That's to say, when we stick our faces in water, our blood pressure, breathing rate and pulse decrease rapidly and our heartbeat slows as our body sh