On 8/19/2012 6:03 PM, meekerdb wrote:

On 8/19/2012 2:43 PM, Stephen P. King wrote:On 8/19/2012 4:30 PM, meekerdb wrote:On 8/19/2012 12:51 PM, Stephen P. King wrote:I understand that 2+2 = 4. I still cannot explain how and why I understand "2+2 = 4". "2+2=4" is easy. "I understand 2+2=4" is quasi infinitely more complex.## Advertising

Dear Bruno,As I see it, the quasi-infiitely more complex aspect of "Iunderstand that 2+2=4" follows, at least, from the requirement thatmany entities capable of making such statements can point toexamples of 2+2=4 and communicate about such statements with eachother however far away in space and time they are from each other.We can ignore the fact that there is a collection of entities towhom the statement "I understand that 2+2=4" has a meaning. Youneed to get a grip on the nature of meaningfulness. Searle hastried to do this with his Chinese Room idea but failed tocommunicate the concept. :_(Maybe Bruno will introduce a new modality to his logicUp="Understands p". :-)Brent --Hi Brent,That would be wonderful if possible. AFAIK, understanding iscontingent on demonstrability, e.g. I understand p if and only if Ican demonstrate that p implies q and q is not trivial and q is truein the same context as p. I think that Bruno's idea of "interviewinga machine" is a form of demonstration as I am trying to define ithere. In my thesis, demonstrability requires that the model to bedemonstrated is actually implemented in at least one possiblephysical world (i.e. satisfies thermodynamic laws and Shannoninformation theory) otherwise it could be used to implement a MaxwellDemon.BTW, it was an analysis of Maxwell's Demon that lead me to mycurrent ideas, that abstract computation requires that at least onephysical system actually can implement it. This is not ultrafinitismsince I am allowing for an uncountable infinity of physical worlds,but almost none of them are accessible to each other (there existevent horizons, etc.).Consider the case where a computation X is generating an exactsimulation of the behavior of molecules in a two compartment tankwith a valve and there exists a computer Y that can use the output ofX to control the valve. We can easily see that X could be asubroutine of Y. If the control of Y leads to an exact partition ofthe fast (hot) and slow (cold) molecules and this difference can beused to run Y then some might argue that we would have a computationfor free situation. The problem is that for the hot/cold differenceto be exploited to do work the entire apparatus would have to becoupled to a heat reservoir that would absorb the waste energygenerated by the work. Heat Reservoirs are interesting beasts....If your computer simulation is acting as Maxwell's demon then youdon't need a heat reservoir.

Hi Brent,

`Good point. I stand corrected! But did my remark about`

`understanding make any sense to you? I am trying to work out the`

`implication of the idea of Boolean algebras as entities capable of`

`evolving and interacting as it is a key postulate of the idea that I am`

`researching. The Maxwell Demon is just a nice and handy toy model of`

`this idea, IMHO. Could the Maxwell Computational Demon "understand" what`

`it is doing? We could add the capacity to have a self-model as a`

`subroutine and thus a way to gauge its actual efficiency against a`

`theoretical standard as a way to implement a "choice" mechanism... See`

`http://www.youtube.com/watch?v=ehno85yI-sA for a discussion of this`

`self-modeling idea.`

The demon makes one tank hot an the other cold so a heat engine runson the difference.

`Yes, the demon would act in a cycle: Compute the simulation to`

`operate the valve to segregate the hot from cold and then use the heat`

`engine to charge a battery, discharging the difference in temperatures.`

`Can this run forever? No, given real world things like friction and the`

`wearing out of parts, but in the idea case it might seem to be able to`

`run for ever.`

Unfortunately this is impossible because such a simulation wouldrequire defining the initial state of the particle's position andmomentum in the two tanks. This is not available for free. Todetermine it by measurement takes at least as much free energy as canbe recovered after implementing Maxwell's demon.

`The idea case would shift the initial position/momentum question`

`into a synchronization question: how is a measurement different from the`

`"inverse" of a simulation? I do not have any good words to express my`

`thought here... Let's see where the discussion takes us.`

Seehttp://www.nature.com/news/the-unavoidable-cost-of-computation-revealed-1.10186for more on this.But if you're doing a calculation once on a given machine it's notnecessary to erase the result. In Feynman's paper on quantumcomputing he note this gets around Landauer's limit. So long as theevolution of the computation is unitary no energy need be dissipated.So I don't see how the result is relevant to Bruno's UD.

`The reversibility argument only works if there is sufficient black`

`memory to work with such that erasure never is necessary. This is just`

`trading off the recource of energy for the resource of a read/write`

`medium. Given the wearing out of parts situation, could this be dealt`

`with so that it is not a problem for the idea case aka no friction, no`

`loss of heat to an external world...`

`See also http://www.csupomona.edu/~hsleff/MD-power-time.pdf`

`<http://www.csupomona.edu/%7Ehsleff/MD-power-time.pdf> for a nice`

`discussion...`

`I am trying to met Bruno half-way in his COMP idea... I just can't`

`let go of the apparent necessity of actual physical implementation, even`

`given that I really like his immaterialist hypothesis. It is too much`

`like Leibniz' PEH and its reliance on the logically impossible. How is`

`Bruno's idea not a proverbial floating castle in the sky?`

Brent

-- Onward! Stephen "Nature, to be commanded, must be obeyed." ~ Francis Bacon -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.