On 25 December 2013 14:26, Edgar L. Owen <edgaro...@att.net> wrote: > > So exactly contrary to your statement, it is precisely special relativity, > properly understood, that puts both the arrow of time and a common present > moment on a firm physical basis. >
OK. I was just going by all the physics books I've read, which apparently claim there is no common present time. Obviously that Einstein chap and the authors of those books didn't understand the full implications of special relativity. > > This insight simultaneously solves two of the big problems of the > philosophy of science, the source of the arrow of time, and the reason for > a common present moment, though no one seems to have recognized this prior > to my exposition in 1997 in my paper 'Spacetime and Consciousness'. > I'm not convinced that there is a big philosophical problem with the arrow of time. If we don't introduce any new physics, the source of the arrow of time can be reduced to two questions - (a) is there any time asymmetry in the laws of physics? (and if there is, is it significant enough to account for eggs forming omelettes, people ageing, sugar dissolving in coffee, and so on) - and (b) are there any boundary conditions on the universe that are sufficient to impose a global time asymmetry on the matter and energy within it? Both these questions can be answered using our present knowledge of physics, and give answers that should be considered first in any discussion of the AOT, before any new physics is introduced. (a) Yes, there is *some* time asymmetry built into the laws of physics - the decay of k-mesons operates in a way that violates time symmetry. All other physical processes, viewed at a short enough distance (or equivalently, a high enough energy) are time-symmetric, as far as we know. It seems unlikely that kaon decay is responsible for the large scale entropy gradient observed in the universe, though it's at least possible it may be coupled to it in some as yet unknown way. (b) the "elephant in the room" in discussions of the AOT is the big bang, which introduces a global time asymmetry on the entire universe. Consideration of the processes which occurred shortly after the big bang leads to the sources of several forms of known time asymmetry. 1 - the formation of nucleons occurred when the energy density of the universe per unit volume fell below their binding energy due to the cosmic expansion. 2 - the formation of nuclei occurred when the energy density of the universe fell below their binding energy due to the cosmic expansion. 3 - the formation of neutral atoms (so called recombination)occurred when the energfy density of the universe fell below their binding energy due to the cosmic expansion. 4 - Stars and galaxies formed when the density of the universe fell enough for (originally small) density fluctuations to be amplified sufficiently to seed their formation. Hence it seems likely that we can get the AOT purely from the global boundary condition imposed by the expansion of the universe plus some uncontraversial, mainly time-symmetric physics. The formation of bound states like nuclei, atoms and stars can be traced back to the existence of a singularity at one temporal extremity, and the lack of one at the other temporal extremity. Since these bound states are a powerful source of negative entropy, this seems very likely to be the origin of the arrow of time. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.