Saibal Mitra wrote: > > >How would an observer know he is living in a universe in which information >is lost? Information loss means that time evolution can map two different >initial states to the same final state. The observer in the final state >thus >cannot know that information really has been lost.
If he is able to figure out the fundamental laws of physics of his universe, then he could see whether or not they have this property of it being possible to deduce past states from present ones (I think the name for this property might be 'reversible', although I can't remember the difference between 'reversible' and 'invertible' laws). For example, the rules of Conway's "Game of Life" cellular automaton are not reversible, but if it were possible for such a world to support intelligent beings I don't see why it wouldn't be in principle possible for them to deduce the underlying rules. As for the question of why we live in a universe that apparently has this property, I don't think there's an anthropic explanation for it, I'd see it as part of the larger question of why we live in a universe whose fundamental laws seem to be so elegant and posess so many symmetries, one of which is time-symmetry (or to be more accurate, CPT-symmetry, which means the laws of physics are unchanged if you switch particles with antiparticles and flip the 'parity' along with reversing which direction of time is labeled 'the future' and which is labeled 'the past'). Some TOEs that have been bandied about here say that we should expect to live in a universe whose laws are very compressible, so maybe this would be one possible way of answering the question. Jesse --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to firstname.lastname@example.org To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---