May 2015 - mathfun@mailman.xmission.com

Re: [math-fun] "differential" in sports writing
by Leo Broukhis 19 May '15

19 May '15

On Date: Mon, 18 May 2015 15:30:34 -0700, Thane Plambeck <tplambeck(a)gmail.com> wrote: > I'm no fan, but how to reformulate this one without getting all wordy? > > "Golden State had a higher point differential vs. Memphis than it did vs. > the Pelicans, despite losing two games to the Grizzlies." What seems to be the problem? differential, ... noun ... 6. a difference or the amount of difference, as in rate, cost, quantity, degree, or quality, between things that are comparable. Leo

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[math-fun] "differential" in sports writing
by Thane Plambeck 18 May '15

18 May '15

I'm no fan, but how to reformulate this one without getting all wordy? "Golden State had a higher point differential vs. Memphis than it did vs. the Pelicans, despite losing two games to the Grizzlies." -- Thane Plambeck tplambeck(a)gmail.com http://counterwave.com/

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[math-fun] Replicoids
by Warren D Smith 18 May '15

18 May '15

I would not recommend believing anything Roger Penrose ever said about computation and/or Godel. His entire book "Emperor's new mind" was insane garbage at the core. Penrose has at various times been brilliant but that book was not it. Here's a fact. A universal turing machine (UTM) is capable of running a program P which will prove that its design indeed represents a UTM. This proof will be valid no matter what input that UTM ever might have. Further, said program P can be proven to be correct, and a verification of said proof could be performed by P itself. (P would be a "verified general-purpose proof-verifier.") This proof will be valid no matter what input might later be given to program P. I suspect that programs of this "self proving" ilk might become important, or even essential, in the future. But right now, most programs are unproven barf, and large programs contain many bugs. And even if self-proving programs become commonplace, that will be no means be a cure-all.

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[math-fun] Replicoids
by Warren D Smith 18 May '15

18 May '15

>> Ask anybody with Tay-Sachs disease or haemophilia. >> As for self-awareness and self-understanding and self-control; all are >> key to allow Lamarckian evolution which would provide a huge >> advantage. > > But that's different than knowing and controlling what goes on inside of > you; that's > changing the way you're made. Including your germ cells. And even that's > not likely to > be possible on the fly. --exactly. For humans. And life as it has been so far. But for future robotoid life, this is no longer necessarily impossible. >> Why do humans have a subconscious, and it controls stuff like >> peristalsis and heart rate, while you cannot consciously (at least I >> cannot)? Answer to that is control would be too dangerous. The human >> thinking mind is buggy. You'd have a bug and commit suicide by >> accident if you had such control and awareness. > > You can hold your breath - but it's not a popular method of suicide. --actually, not. If you try, and manage to reach the point of of unconsciousness, your subconscious brain would take over to save the situation. One could imagine limited conscious control within limits imposed by a subconscious like that; but so far there has never been a thinking being, so this so far has not been a possible design for life. For future life it could be an option. >> Too risky. And even >> your subconscious cannot control your DNA and immune system, which is >> for technical reasons, but even if your brain could, that would be >> very risky. It would however have great advantages too, such as cure >> cancer. > > While you were using all your computing power to analyze DNA strands and > T-cell receptors > you'd get run over by a car. --again. For past life, this has been the case. For future life with perhaps far greater computing power, this need not be a limitation. >> Any future robot Lamarckian life might have to involve >> self-proving >> code, to avoid bugs, or extensive self testing with backward >> versioning system every time it makes a modification, or something, to >> enable it to safely perform these risky moves. >> In general program-understanding is undecidable problem no matter who does >> it, >> but programs that come with proofs can be understood. > > You can prove what a program will do with given inputs, but a human like > program will need > to deal with unforseeable inputs and errors. --programs can come with proofs that prove theorems valid about ANY input. > Of course a TM will read its tape; that's how it computes. But you must > mean reading a > record of computation in order to learn from it (what humans call > reflection). Are you > assuming infinite computational capacity?...So it cost nothing to read a > transcript of > your past computations. > Brent --I'm not following whatever you are trying to say here.

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[math-fun] Alcazar
by James Propp 18 May '15

18 May '15

My 6-year-old daughter and I have been really enjoying the Alcazar app, which I just learned about from an MAA publications (either Focus or Horizons). Have any of you played with it? Jim

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[math-fun] Replicoids
by Warren D Smith 18 May '15

18 May '15

>> Some people think humans are self-aware. I dispute that. You are unaware of, >> and unable to control, and do not understand, most of what goes on inside you >> or your brain. >Of course there are good reasons for that which will apply to AI life forms as well. >First, there's no advantage to it, which is one reason natural selection didn't arrive at >it. --wrong. The reason natural selection did not provide Lamarckian evolution was the map from genotype to phenotype is so complex as to be essentially uninvertible. So it simply could not be done. It would be hugely advantageous if we could do Lamarckian evolution ("intentional self improvement"). Ask anybody with Tay-Sachs disease or haemophilia. As for self-awareness and self-understanding and self-control; all are key to allow Lamarckian evolution which would provide a huge advantage. Why do humans have a subconscious, and it controls stuff like peristalsis and heart rate, while you cannot consciously (at least I cannot)? Answer to that is control would be too dangerous. The human thinking mind is buggy. You'd have a bug and commit suicide by accident if you had such control and awareness. Too risky. And even your subconscious cannot control your DNA and immune system, which is for technical reasons, but even if your brain could, that would be very risky. It would however have great advantages too, such as cure cancer. Any future robot Lamarckian life might have to involve self-proving code, to avoid bugs, or extensive self testing with backward versioning system every time it makes a modification, or something, to enable it to safely perform these risky moves. In general program-understanding is undecidable problem no matter who does it, but programs that come with proofs can be understood. > There are some disadvantages: additional memory and processing required which would slow down decisions. Second, although the Lucas-Penrose argument doesn't show what they thought, I think it does show that you can't know what program you are (but other people can). --huh? Seems to me if I were a turing machine, I could read any part of my program tape. And having this capability would necessarily not slow down my decisions in the slightest.

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[math-fun] replicoids
by Warren D Smith 18 May '15

18 May '15

>Life is always relative to some environment. We're alive, but we don't do photosynthesis; we depend on plants to create organic compounds for us. And the plants depend on the Earth's environment and light from the Sun. So can can conceive of robotic life that reproduces by scavenging electronic components from machines we discard. >I have a friend who says cigarettes are a life-form parasitic on human beings. --indeed. But, e.g. cyanobacteria appear to be capable of survival even if all other earth life were wiped out. Really one could argue humans, or for that matter any vertebrate, are not "alive" viewed in isolation, but only when viewed as part of a multi-species community. The only attempt I know of to actually set up a self-sufficient such ecosystem which included humans ("biosphere 2"), was a virtually catastrophic failure, because knowledge of what such an ecosystem could be, was vastly inadequate. >I'd say the essential aspect of life is the drive to reproduce and the ability to evolve. If robots instantiate those two attributes, then they will be just another life form. They can evolve to be social and smart, but it's an interesting question whether being smart in the sense of playing chess or proving theorems is an evolutionary advantage. Empirical data suggests maybe not. --little or no earth life is suited to survival in space. This "robot life" would not have that limitation. It could colonize the galaxy, while we humans could not. To do so, probably would require great intelligence (in some sense, anyhow) in comparison to any human. Even just maintainence on itself (redesigning itself as it did so), would take great mental ability. This kind of life also would be the first "self aware" life. Some people think humans are self-aware. I dispute that. You are unaware of, and unable to control, and do not understand, most of what goes on inside you or your brain. And unable to re-engineer yourself. This lifeform also would be the first capable of "Lamarckian evolution." This all would be a huge advance versus all previous life. If and when it gets going, it will dwarf us. -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)

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[math-fun] Replicoids
by Warren D Smith 17 May '15

17 May '15

Ventner's "artificial bacterium" is simply a natural bacterium with synthetic DNA, and the DNA sequence is chosen by picking your favorite selection of gene sequences from Nature. I do not regard it as "artificial life" at all. It is a bit like, if you wrote some masterpiece book, then I cut out some pages with scissors and rearrange them and declared that (therefore) I had written a book. It's good if Ventner et al can develop the technology to do this, and custom made to order bacteria might become very useful and important, but it is hardly "creating life." Now if, say, we had a robotic factory that builds more robots, and the robots also perform all the mining to get the materials, maintenance on the factory etc... then I would say we had genuinely "created life." And this kind of "life" could in principle be far superior to the old wetware kind in various ways, such as ability to live on the moon, no need for water, much greater adaptability to changing environment, far longer lifespan, superior ability to play chess, etc. I would imagine, in fact, that this kind of life will be the important kind sufficiently far in the future, from the point of view of the galaxy. We won't be. And the research into ConwayLife, 3D printers, and AI, all just are preliminary steps to creating this.

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[math-fun] small UTM's etc
by Fred Lunnon 17 May '15

17 May '15

Some of these articles look potentially interesting --- provided you're sufficiently ingenious, privileged, or wealthy to circumvent the paywall! http://content.iospress.com/journals/fundamenta-informaticae/138/1-2 WFL

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[math-fun] 96 fractions
by Stuart Anderson 17 May '15

17 May '15

Have to rephrase that question. Sent from my iPhone

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