Wei Dai: If we consider our observable universe as a computation, it's rather atypical in that it doesn't seem to make use of the erase operation (or other any operation that irreversibly erases information). The second law of thermodynamics is a consequence of this. In order to forget anything (decrease entropy), we have to put the information somewhere else (increase entropy of the environment), instead of just making it disappear.
___ Not sure I get your point (and it is also possible you write 'erase' actually meaning 'delete', which is different, at least if you try to 'delete' quantum states.) Anyway it is (perhaps) possible to say that (according to Everett) the information content of the original universal state is going to be transformed into hidden information content of the correlations between the different 'branches'. It seems to me that this process is different from the (usual) entropy increase of the environment, since the 'environment' here is completely inaccessible. The increase of entropy of that inaccessible environment is, in part, balanced by the entropy decrease of our, actual, present 'branch', due to its growing specification, or decoherence, or selection (in turn due to all measurements performed untill now). --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to email@example.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---