At 16:07 -0800 8/01/2003, Hal Finney wrote:
The interesting aspect from this list's perspective is how to regard infinite-time cosmologies. Does it make sense to imagine a universe which has had an infinite past? How could we simulate that on a computer, if there were no starting point?
We certainly cannot simulate a 3-person infinite past history. But imagine we simulate a society-world of researchers in a computer, and that we would like those researchers never guess anything about our own reality level. Now, the computer is locally finite (i.e. at each time it is finite but it is capable to grow indefinitely) so that those researchers, experimenting their reality, will find little local inconsistencies. For example they will correctly infer some standard model particle theory from they high level experimentations, but as soon they will build particle accelerator to verify their theories, discrepancies will appear (just because we have not simulate the society-world at such a detailed level. So now those researchers can infer that they are simulated at some different reality level. But this is what we don't want. So let us add a subroutine which observes the researchers, and each time reserachers find (serious) discrepancies, the subroutine freezes the researchers and refines their level of reality. Now, it is quite logically possible that the refining need not only to add sub-particles, but need to add past further "past-interactions". So, although that past is generated, little by little, in the 3-future, it will happen that from the 1-perspective of the simulated researchers their stories will look as if they are infinite in their past. Is not UD* like that? Open problem. But quite possible once we distinguish the 1-time of the simulated people and the "3-time" describing the definite steps of the UD in Platonia.