My most recent beef is with the Science Channel’s ‘Prophets of Science Fiction’ episode on Philip K. Dick. In this episode it was asserted that the fiction of Dick anticipated ‘parallel words’ which may be implied by recent work in theoretical physics. This assertion was given credence by several ‘authorities’, including photogenic science popularizer Michio Kaku. Dr. Kaku went on to imply that Dick was anticipating ‘parallel universe’ scenarios which might be derived from String Theory.
This was the point at which I began to smell a rat. The ‘parallel universes’ found in the novel cited (The Man in the High Castle) seemed to most closely resemble those implied by the ‘Many Worlds’ interpretation of quantum mechanics. This motivated me to do perhaps five minutes of research. ‘The Man in the High Castle’ was published in 1962. The ‘Many Worlds’ interpretation of quantum mechanics is based on the work of Hugh Everett, which was published in 1957. I guess it’s fairly easy to be ‘prophetic’ about events which have occurred in the past.
I doubt that there are more than a handful of physicists in the world who are unaware of Everett’s work. I find it disturbing that not only did Dr. Kaku give credence to the program’s claim of ‘prophecy’, he also used the program as an opportunity to plug String Theory. I have no idea whether this was a mistake or intentional deception. Neither possibility is particularly flattering to Dr. Kaku.
In closing, I encourage the reader to explore the excellent critiques of String Theory written by Lee Smolin and Peter Woit. These make a strong case for the proposition that pursuit of String Theory has been a dead end, and has been detrimental to progress in theoretical physics for 30+ years.
]]>Last time I talked a bit about games like ‘rock, paper,scissors’ and about generating keys for one-time-pad encryption. I really should have specified ‘an arbitrarily long series of games of rock, paper, scissors’ and ‘a one-time-pad encryption key of arbitrarily long length’. The reason that a truly random (vs. pseudo-random) number generator is attractive in these applications is that it can produce a string of as great algorithmic information content (Kolmogorov complexity) as desired while using finite resources. This is in contrast with a Turing machine, where the algorithmic information content is limited to no more than the amount of memory. I may be picking nits here, but there is a difference between provably optimum and ‘plenty good enough for all intents & purposes’.
With that little aside taken care of let me get back to Squires. In section 3.4 of his book the author discussed the ‘why’ of consciousness: the (presumably evolutionary) advantages that it confers. Two possibilities are mentioned:
I just can’t buy the first argument. If ‘wanting’ is a unique attribute of consciousness, then it seem that it would be lacking in a plant or an earthworm. Regardless of this, a plant seeks the sun while an earthworm avoids it. They do this with as much fervor as any amount of ‘wanting’ could supply. I don’t see any evolutionary advantage here.
Although the second argument has been criticized, I believe that it may be an overly specific example of a more general principle. That humans are capable of planning behavior clearly has great survival value. Rather than reacting to stimulus second-to-second, we can anticipate future states of the universe and gear or present actions to that anticipation. Computationally, it seems that the way to implement this ability is to construct internal mental models of the universe. To be relevant to survival it would seem that a representation of the ’self’ would be an essential component of these models. Although we have a quite vague definition of consciousness, it seems that self-awareness must surely be part of it. I suspect a strong connection between self-awareness and the mental modeling used in planning.
Although I had planned to talk about the ‘Chinese room’, I feel that I’m running a little long here, and will save that for the next post.
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It seems inevitable that this discussion is going to be asking far more questions than it answers, but I feel that that’s OK as long as the questions are interesting. The most difficult areas to deal with are questions regarding consciousness, because it’s hard to even find an appealing definition of what it is. At this point I want to throw out some question that I find interesting, and may serve as a kind of preview, or appetizer for what is to follow:
At this point I’m sure that at least some of these questions are related, for example the question regarding random numbers and game theory. Specifically, suppose I try to imagine a situation in which a combination of Turing machine plus random number generator performs some task better than a Turing machine alone. Whenever I do this I seem to come up with things like the ‘rock, paper, scissors’ example, generating a key for one-time-pad encryption, or other examples which seem to be the province of game theory. In all of these examples (that I can think of) I am competing against a conscious (or at least intelligent) opponent. Is this due to some relationship between consciousness and randomness, or is this simply due to my lack of imagination? I find these questions far too difficult to answer on my own, so I hope to at least get some discussion going.
In the next installment on this topic I plan to discuss some of the Squires book, including a discussion of Searle’s ‘Chinese room’ thought experiment. I guess that’s enough for now. I welcome and look forward to comments.
]]>In view of the example of TEPCO’s past behavior in Japan it is clear that we need strong disincentives for fraud and falsification of safety documents. I contend that fines imposed on corporate entities are inadequate disincentives in this context. To paraphrase a famous quote, there’s nothing like the prospect of a prison sentence to focus attention.
Defrauding (or conspiring to defraud) nuclear industry regulatory agencies should be a federal crime punishable by up to 20 yr. imprisonment per count where issues impacting safety are involved.
We can also allow market forces to help industry make more rational decisions regarding site selection and design decisions. The amount of liability coverage required to be purchased needs to be commensurate with potential damages. The vast majority of this coverage should be purchased on the open market. Insurers may need to be subject to special auditing and financial requirements to be sure that they can pay out potential claims without government intervention.
It seems that it would be entirely reasonable to scale required liability coverage based on potential damages. This would encourage industry to make more rational decisions regarding site selection. Required liability coverage should be determined by taking the sum of several factors, only one of which I will elaborate: It seems reasonable that nuclear plant operators should be required to carry additional coverage for plants located near population concentrations. My personal opinion is that additional coverage of $100,000 per person residing within 50 miles of the site would not be unreasonable.
]]>Exercises 1: 7th Chord Arpeggios in C Major - pdf format / gp5 format
This is really straight-forward stuff. I use what I call the no-stretch position for the C Major scale: middle finger on the root note on the 6th string. That puts the index finger on the 7th fret for C Major.
Exercise 2: 8 Bar Blues Arpeggios in A - pdf format / gp5 format
This might require a little more explanation. The 8-bar progression I’m using is I-IV-I-V-I-IV-V-V. I try to arrange my fingering to use no-stretch positions. Where it gets a little weird is that rather than using a single scale, blues is often harmonized using dominant chords throughout. This means that rather than the I Maj 7, IV Maj 7, V7 progression you might expect, a I 7, IV 7, V7 progression is much more common. (Of course, it’s also common to mix in the pentatonic minor and blues scales of the I chord root.) Because of this, playing mixolydian scale tones over the chord changes works pretty well. In A, my scales would be A mixolydian (D Major), D mixolydian (G Major), and E mixolydian (A Major). For this exercise, I also wanted to use 9th chords, to give it a little bit jazzier feel.
Finally, if I was going to use a no-stretch position for my I chord (A mixolydian / D major), that would put me quite high on the fretboard (index finger on 9th fret). I didn’t want to do this, so my solution was to replace the A9 chord with an A6add9 chord, played at my A major no-stretch position. I think it actually sounds pretty good.
I know that’s a really long-winded and perhaps boring explanation for a pretty simple exercise. I also know that someone is bound to say “all that trouble to avoid stretching a finger to hit C natural”. I still thing it’s a good exercise, and helps to get a person thinking in terms of what scales and modes work over various chords.
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]]>In the interview, Massimo is discussing the ‘trans-humanist’ idea of uploading a human consciousness into a computer. The analogy he used was a comparison between a real plant vs. the simulation of plant biochemistry on a computer. Dr. Pigliucci correctly pointed out that, unlike the real plant, the computer does not synthesize real sugar. If the defining aspect of human consciousness could be equated to production of certain real neurotransmitters, such as acetylcholine, serotonin, etc., his analogy might hold. Although there is much speculation but little agreement on the nature human consciousness, I doubt that specific chemical compounds are the defining factor.
My suspicion is that human consciousness is an evolutionary adaptation related to planning. To know the likely future consequences of our actions, we seem to construct mental models, similar to computer simulations. To be useful, these mental models must include models of ourselves, hence our self-awareness.
I think an alternative to Dr. Pigliucci’s analogy might be a movie that’s available on either DVD or VHS. The physical media are different. Even the underlying technologies are vastly different. It’s still the same movie.
]]>Getting a spacecraft up to an altitude of 100km or so is really not that big a deal, requiring a specific orbital energy of around a megajoule per kilogram. What is a BFD is having a high enough velocity to establish an orbit. This requires around 35 megajoules per kilogram for low earth orbit, or 57.5 megajoules per kilogram for geostationary orbit. Put another way, Virgin Galactic is only 2% to 3% of the way to being able to do anything more useful in space than a very brief joy-ride.
I’m totally in favor of encouraging private investment in space transportation. On the other hand, we need to maintain a sense of perspective when evaluating the impact of space policy decisions.
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]]>The AAA slogan seems to admit four situations with respect to any proposition ‘p’.
This seems to argue for a four valued logic of the ‘relevance logic‘ variety. I’ve been playing around with some Prolog code to implement this. My terms begin with characters ‘x4′ to indicate the four-value logic. Example code follows:
x4Truth(Y, x4T) :- Y, \+ x4not(Y).
x4Truth(Y, x4F) :- x4not(Y), \+ Y.
x4Truth(Y, x4C) :- Y, x4not(Y).
x4Truth(Y, x4U) :- \+ Y, \+ x4not(Y).
x4not/1 is simply a way to assert that evidence exists indicating that the argument is not true. x4Truth/2 gives a way to determine one of our four logical values based on the provability of propositions p and x4not(p). x4T, x4F, x4C, and x4U are the values of the logic where:
My next step is to investigate unary and and binary operators on these values, determine which possibilities are useful and what their implications are.
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]]>Semantic Web for the Working Ontologist,
Effective Modeling in RDFS and OWL
by Dean Allemang and Jim Hendler, ISBN 978-0-12-373556-0
and
Learn Prolog Now!
by Patrick Blackburn, Johan Bos, and Kristina Striegnitz, ISBN 1-904987-17-6
Semantic Web… is quite inspiring in giving examples which illustrate the potential of Web 3.0 technologies. Readability was greatly enhanced by the authors’ decision to forgo XML serialization, and use n3 serialization instead. This book is aimed primarily at potential authors of semantic web content. There in ample discussion of how inference works in RDF, RDFS, and OWL. Indeed, the semantics of these languages is best described by the inferences which can be generated. The ways in which RDF stores, query languages, inference engines, and applications interact is presented in quite broad strokes. It is tacitly assumed that the internals of these are not the immediate concern of the working ontologist. This limitation in the scope of the book seems entirely appropriate. For those interested in trying their hand at RDF/OWL authoring, trial editions of TopBraid Composer are available from TopQuadrant.
When I think about inference, I think Prolog. I flirted with learning Prolog back in the ’90s, but have lately had my interest renewed. I don’t know if anyone is writing Web 3.0 apps in Prolog, but it seems like a natural match. By far the best text for learning Prolog I’ve found to date is Learn Prolog Now! This is currently my ‘go-to’ text, taking precedence over those by Clocksin, Bratko, and Sterling & Shapiro. I’ve can also heartily recommend a couple of Prolog IDEs for those interested: tuProlog, and SWI Prolog. tuProlog should be of particular interest to the Java programmer.
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