Re: Paper+Exercises+Naming Issue
On Sun, Jan 15, 2006 at 01:04:02PM -0500, Benjamin Udell wrote:
>
> The "dovetailer" keeps sounding like a powerful idea. I do remember that it
> has often been mentioned here, but somehow I failed to pick up a sense of
> what it was really about. Was there a message to the Everything-List in which
> it was explained so that non-experts can understand it? I'm not asking you to
> track that message (or series of messages) down, but if you or somebody
> remembers around which month it was, that should be enough for me to find it.
> Or is there a link to a Webpage with such an exposition?
Do a Google search, or a search on the everything list archives eg
Google "everything list dovetailer".
>
> Level III varies across quantum branchings. Level II varies across times and
> places along a single quantum branch in such a way that its features come out
> the same as Level III's features.
This is not my reading. Level II universes vary their fundamental
physical constants, eg G, alpha and so on.
Level I universes merely vary in time and space, but sufficiently
separated as to be causally independent.
...
>
> But I haven't noticed anybody here talking about variational principles or
> optimizational equations in any connection, much less in relation to Level
> IV. (While there is an obvious echo of optimization in applying Occam's Razor
> to Level IV's mathematical structures, this doesn't seem to involve any
> application of mathematical extremization, variations, Morse Theory, etc., so
> it seems not really the same thing. It's certainly not the only echo between
> a mode of inference (present instance: surmise, simplest explanation) and a
> mathematical formalism (extremization, shortest paths, etc.).)
>
Extremum principles come up mostly in Roy Frieden's work. No-one has
managed to integrate Frieden's stuff into the usual framework of this
list, so little mention has been made of it, but I do mention it in my
book. The hope is that some connection can be forged.
--
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Re: Paper+Exercises+Naming Issue
Le 15-janv.-06, à 19:04, Benjamin Udell a écrit : The "dovetailer" keeps sounding like a powerful idea. I do remember that it has often been mentioned here, but somehow I failed to pick up a sense of what it was really about. The Universal Dovetailer is a program which generates and executes all programs. Its existence is a non trivial consequence of Church thesis. Please recall me to explain this in detail in one or two weeks. The necessity to dovetail (that is to run successiveley on the initial segement of the execution never waiting any programs stop is due to the fact that the always defined programs cannot be generated mechanically (this can be done in the case of all programs). Actually I have already explain this on the list (in 2001) but the escribe archive seems no more working again, and the new archive seems not go enough backward in time. The first published paper where I define it, is "Mechanism ans Personal Identity" paper: http://iridia.ulb.ac.be/~marchal/publications/M&PI_15-MAI-91.pdf Russell Standish attributes it (wrongly) to Schmidhuber in his book. My fault, perhaps, because I have (charitably) compare Schmidhuber "great programmer" with the Universal Dovetailer in some message to James Higgo. You can google on "universal dovetailer". I have also introduced the distinction between the first person, plural and non plural, and third person view, although this has been done by some philosophers of mind in different context before. I introduce it in the self-multiplication and UD context. This is explained in most of my papers (recent or not). Schmidhuber never accepted that distinction (or took it as unscientific like may "scientist", but that is a category error). Actually he leaves the list at the time most people acknowledge the idea. Schmidhuber's work is more akin to a constructive physics based on Universal effective prior than an attempt toward a TOE capable of treating the mind-body relation problems. Here too with some imagination we can see the shadow of that 1-3 distinction appearing in Tegmark through the frog and bird view. In the Quantum Mechanics setting the 1-3 distinction appears in Everett fundamental paper under the term "subjective" and "objective". The full conceptual power of the UD arises from the 1-3 distinction applied to it. This leads easily to the mind/matter reversal (except for the remaining "movie-graph/Occam difficulty). Of course "dovetailing algorithm" are well known by computer scientists as a way to simulate parallelism on a sequential computer. Was there a message to the Everything-List in which it was explained so that non-experts can understand it? I'm not asking you to track that message (or series of messages) down, but if you or somebody remembers around which month it was, that should be enough for me to find it. Or is there a link to a Webpage with such an exposition? I have a lot in my web pages but the Everything Archive does not function properly. I will try to find my own backup, once I have more time. But now, Ben, it could be an opportunity and a pleasure for me to explain the UD and the UDA, again. (Those who have already understand are not obliged to reread the explanations but actually not many people have acknowledge a complete understanding of it). After all, the interview with the lobian machine will bear on the UDA. The UDA explains why physics is reduce to a measure on computations "seen from some 1-point-of-view", and the lobian machine will be able to extract the logic of probability one. This is enough to make the comparison with quantum logic (the logic of probability one in physics). Bruno http://iridia.ulb.ac.be/~marchal/
