Note, too, that in this model of a universe I may want to include models of things that are rather large, and things that are somewhat small, some which I described, and also of things that are much smaller, and even things that are very small indeed. I have positioned my house and garden in a valley, on a continent, on a planet, orbiting a star, which is in the middle reaches of a galaxy, which is somewhere in the vastness of our observable universe, and in my garden, I might model a tree (of which there are a considerable number), with branches, and maybe branchlets, and on one of them, a leaf, and its surface is divided into little irregular regions by many veins, and within one of those regions can be detected many cells. I might perhaps want to count them, and then I am interested in immersing my mind in the structure of a cell, too. I imagine it as a little sea, which, in fact, moving into it, is not so little at all, but, at any rate, through it there extends a network of something like tendrils, protein structures, and, if we approach one of them very closely, we should see, in it, a hubbub of activity, certain things, moving about.
It's not that I am planning a new career in biomechanics. I just want to emphasize the possibility of a CAD that is infinite.
