Re: relevant probability distribution
On 15 Jun 2002, at 14:27, Russell Standish wrote: > > No the issue concerns any conscious "program", rather than any > particular one. The fact that there are vastly more amoeba than homo > sapiens tends to argue against amoebae being consious. > This remind me of Jack Vance novels "Alastor". One of the characters is the king that rules over a vast area of the galaxy. He likes to travel incognito among his subjects, and he often ask himself the question: "There is billions of men and only one king. How is it possible that it happens that I am the king ?" Do your position about this is that subjects are not conscious, only kings? >From a third-person point of view (the reader of the novel), the question is simple. There is billions of subjects, and they can all ask themselves "Why I am me and not someone else ?". The problem is we have only a first-person point of view on our universe (or on the "everything"). We must use our imagination, to do thought experiments, to get a third-person point of view. Matthieu. -- http://matthieu.walraet.free.fr
Re: decision theory papers
On 18 Apr 2002, at 20:03, H J Ruhl wrote: > > 5) I do not see universes as "splitting" by going to more than one next > state. This is not necessary to explain anything as far as I can see. > > 6) Universes that are in receipt of true noise as part of a state to state > transition are in effect destroyed on some scale in the sense the new state > can not fully determine the prior state. > "The new state can not fully determine the prior state" only means that the application that give the next state from the prior state is not bijective. Let's call S the set of all possible states of universes. T is the application that give the next state from a prior state. Without "true noise" T is an application from S to S T S > S prior state > next state If the application T is not bijective (There is no reason that it should be) then the new state can not fully determine the prior state. Now with the mysterious "true noise", the prior state alone can not determine the next state. T is not an application from S to S. T is an application from SxN to S. T S xN --> S (prior state, noise)--> next state. In your system universes are sequences s(t) defined by a given initial state s(0) and a given application T. Without "true noise" the sequence follows the rule: s(t+1) = T(s(t)) But with the "true noise", s(t+1) = T( s(t), noise(t)). What is noise(t) ? Is it true random ? I would like to know your definition of true random. I suppose noise(t) is an arbitrary sequence in the N set. Why choosing an arbitrary sequence of noise ? I prefer to consider the application T' from S to the set of subset of S. T'(s) is the union of { T(s,n) } for all n element of N. T' is the application that give all possible next state for a given prior state. This means that when we consider a starting state s(0) there is not only a sequence of successive states but a tree of all possible histories starting from s(0). In other words, "true noise" causes the universes to "split". If you say your universes don't split and are affected by a "true noise", you are choosing an arbitrary sequence of noise. This is a kind of physical realism. On this list, we are mathematic realist (some even think only algebra has reality), and we think physical reality is a consequence of math reality. Don't say again "my" system is too complex, I just tried to define clearly your system. Matthieu. -- http://matthieu.walraet.free.fr
Re: origin of notion of computable universes
On 15 Apr 2002, at 16:17, Juergen Schmidhuber wrote: > I am also interested in pointers to early fiction. For decades > SF authors have been writing about downloading minds onto machines. > And when I was a kid in the 1970s (?) I heard a fictional play on the > radio (maybe British?) about researchers in a submarine who discover > that they are actually living in a rather crude computer simulation. > I came across variants of this theme again and again in numerous > more recent SF novels - but who was the first to write down such > ideas? > I don't know who is the first, but there is the fabulous novel "Simulacron 3" by Daniel F. Galouye, first published in 1964. Scientists simulate a town in a big computer to collect marketing data. There is an amazing description of a memory page exception, lived by a simulated character ! It has been adapted by Josef Rusnak as "The Thirteenth Floor". (I haven't see the movie.) Matthieu. -- http://matthieu.walraet.free.fr
Re: Juergen's paper
On 22 Jan 2002, at 23:28, H J Ruhl wrote: > > > > > > I do not see that at all. Why does it need a history? All it needs is > > the > > > capability of finding a next state. > > > >It doesn't need the capacity to find the next state. If it has that > >capacity, then the history is computable. > > I said "capability of finding a next state". I did not indicate how it > found such a next state. It could for example do so at random. > An universe can be an oriented graph of states. Each state has no, one or more next states. It also has no, one or more previous states. This universe may be computable. To compute it doesn't means you start from an unique initial state and you go from it to the only next one and so on. If there is conscious beings in this universe. They will perceive the time flowing as they go from a state to a next one, and again. But from a third person point of view, this univers is a static (and so deterministic) mathematical object. When for a given state there is more than one next state, it is for the concious being as if random rule their future. They may think their universe is not deterministic, except for those who has an Everett-like theory. When there is no next state, it's the end of times. This kind of universes doesn't have an history, but many histories. Each way in the oriented graph is an history. Even loops are possible. Many different histories can lead to a given state. If our universe is this kind of graph, the big-bang may not start from an inital "eden" state (which has no previous state) but from a set of states that can loop. After the big-bang I suppose there is no loop. Matthieu. -- http://matthieu.walraet.free.fr
Little presentation
Hi, Instead of replying too quickly to a mail, maybe I should introduce myself before. I'm a 28 years old network software engineer. I have exchanged some mails with Bruno Marchal quite a long time ago, after an article in "Pour la Science" (french edition of "Scientific American".) I also have read his thesis : "Computability, Physics and Cognition". I'm a science-fiction reader and Greg Egan fan. I have found "everything" list from Egan's web site. I agree with Max Tegmark statement : that mathematical objets exist, "self- aware substructures" of these objets perceive their environment as real and this is why we imagine that our universe is real. I don't see why a "measure" is needed. I'm not sure such a measure could be intrinsically defined. I will try to argue about this later. I hope I don't get you bored with things you have already spoken about a thousand times. Matthieu -- http://matthieu.walraet.free.fr
Re: Finite time and infinite space
On 15 Jan 2002, at 11:31, [EMAIL PROTECTED] wrote: > One of the things that strikes me as most peculiar and unexpected about the > universe is this: that it is apparently finite and inhomogeneous in time, > yet infinite and homogeneous in space. > The universe is finite : My short term memory last less than 10 minutes. So the universe is contained in a sphere of 600 light-seconds radius around my head. Matthieu. -- http://matthieu.walraet.free.fr