Biology gives you a brain - Life turns it into a mind

kw: book reviews, nonfiction, science, predictions, brain, mind

The title is a quote from Jeffrey Eugenides, and succinctly expresses my understanding of the mind. A longer exposition on the mind and its possible futures is found in The Future of the Mind: The Scientific Quest to Understand, Enhance, and Empower the Mind by Michio Kaku. Dr. Kaku, a physicist whose specialty is string theory, is well known to those who watch the Science and Discovery Network cable channels. He is always willing to provide a series of provocative and quotable sound bites on scientific subjects.

In The Future of the Mind he first explores what the mind is, particularly the conscious mind, and defines consciousness in his own unique way. I like his approach:

Human consciousness … creates a model of the world and then simulates it in time, by evaluating the past to simulate the future. This requires mediating and evaluating many feedback loops in order to make a decision to achieve a goal. (p 46)

I would only add: goals can be both innate (hunger or reproduction) and derived (the engineering steps needed to construct a bridge, even though the bridge is part of a larger, innate goal). The reference to feedback loops harks back to an earlier discussion of levels of consciousness.

• Level 0: Stationary organisms or mechanisms that react to one or a very few feedback loops in a few parameters. The lowest possible consciousness is that of a thermostat, which he defines as Level 0:1 because it reacts to one parameter, Temperature. Plants react to Light, Gravity, Temperature, Moisture and perhaps a few Mineral Concentrations, and could be characterized as Level 0:n where n is about 10.
• Level 1: Motile creatures (and perhaps some mechanisms) that can thus react to changes in space and location, particularly animals with a central nervous system such as fishes and reptiles.
• Level 2: Social animals, particularly those that express a theory of mind and are thus reacting to the possible or probable intentions of their fellows and other animals such as predators or their prey. The number of feedback loops that Dr. Kaku might enumerate here grows into the hundreds or thousands.
• Level 3: Future consciousness, which may or may not be among the capabilities of some nonhuman animals, but is a characteristic of human consciousness. Planning for the future, particularly with multiple contingencies, and not as an instinctual reaction, is the hallmark of this Level.

It occurs to me that Level 3 is an iffy business. Most people plan only when they have no alternative, and often do so badly. I suspect that we are pretty new at this. It may have been achieved less than 100,000 years ago. Dr. K doesn't mention the "when" of Level 3.

At this point I must note a puzzling item, an apparent error. In his student years, the author experimented with Sodium-22 (Na-22), an isotope that emits positrons. He then mentions, in two places (pp 5, 26), that Na-22 is used for taking PET (positron emission tomography) scans of brain activity. Not really. Wafers containing a tiny amount of either Na-22 or Ge-68 are used as "spot markers", stuck on the outside of the body to provide orientation markers, typically for organs other than the brain, which has such a distinctive shape that markers are usually not used. Brain scanning in particular uses Fluorine-18 in a glucose analog (fluorodeoxyglucose or FDG); glucose concentrates in active areas of the brain, and FDG with it. The positrons detected in the scanner "light up" these active areas on the scans.

F-18 has the virtue of a very short half life of 110 minutes and must be generated in a reactor possessed by the imaging facility just before use. Na-22 and Ge-68 have half lives of 2.6 years and 8.9 months, respectively. Also, neither can be used to produce a glucose analog. Even if they could, to achieve a similar level of positron emission, much larger amounts would have to be used, which would continue to emit at that level for many months or years. Thus F-18 is thousands of times safer in the body than the other two.

Onward. Leading up to the multilevel model of consciousness, I find this statement:

Self-awareness is creating a model of the world and simulating the future in which you appear. (p 36)

This leads later to a discussion of whether machine consciousness can become self-aware. A recent article in Wired by Kevin Kelly discusses Artificial Intelligence as an emerging "cloud service", a scalable on-demand service already being used, for example, by face recognition modules in programs such as Picasa and Photo Gallery. Kelly particularly notes that consciousness seems to need an element of chance to make it work. If this is so, conscious intelligence is inherently less than 100% reliable, so that future AI offerings may need to be certified as "Non-Conscious". Thus his view of machine intelligence is as something supplementary to the "natural" consciousness we experience, and is best kept unaware.

Dr. Kaku believes just the opposite, and discusses at length the possibility of machine self-awareness, and the possibility that we will be replaced by machines. The word "robot" is bandied about, with little acknowledgement that the word has two very distinct, very different uses in science fiction versus industry.

Industrial robots are actually better described either as Waldoes—based on "Waldo" by Robert A. Heinlein in 1942—if they are directly human-controlled (this includes drones), or as programmable actuators when they are controlled by a program running in a connected computer. Thus they are a logical extension of NC (numerically controlled) machining.

Autonomous robots as described by Isaac Asimov in I, Robot and all his later "Robot" books and stories, whether subject to his "Three Laws of Robotics" or not, are still decades in the future, if indeed they can be realized as self-contained entities at all. Current state-of-the art autonomous robotic mechanisms, such as the car from Stanford that finally won the DARPA self-driving competition in 2005, are barely at the threshold of Level 1 consciousness. Their "planning" capabilities are pre-programmed, an analog of animal instinct, and limited to finding a way to specific GPS coordinates.

Moore's Law states that the number of devices on a computer chip tend to double about every 18 months. It is a trend Dr. Gordon Moore observed, but has become a self-fulfilling prophecy driven by the profit motive. Several related trends include the power requirements of a certain amount of processing speed: watts per gigaflop (GFLOP, where FLOP means FLoating-point OPerations; per second is implied) seem to fall by about half every two years. This allows us to make a prediction, based on the assumption that Moore's Law will continue to hold for a long enough period. Today's fastest computer system has processing speed and memory capacity very similar to the human brain, but consumes 9,000,000 watts, including air conditioning. The brain maxes out at 20-25 watts. Nine million divided by 25 is 360,000, or 2 to the 18.5 power. That implies at least 37 years before human-level AI can be run with 25 watts.

Moore's Law is already in trouble, however. The fastest computer chips today run at about the same speed as those of about 10 years ago. Greater total power in a "CPU chip" for your PC is achieved by putting multiple processors on the chip. That is why they are now called "multicore" CPU chips. The computer I am using has a 4-core CPU. Commercial chips top out at 16 cores (as of late 2014), and the Watson supercomputer has thousands of these wired together.

I don't hold out much hope for "quantum computers" (qC's). The hype about these devices is beyond incredible. Their operation requires maintaining coherence among some number of quanta, typically electrons or ions held in some kind of magnetic trap, and being able to decohere them in sequence for readout into ordinary, electronic devices. Holding coherence longer than a small fraction of a second is comparable to balancing a pencil on its point. I suspect that the ancillary machinery needed for maintaining coherence and, even worse, manipulating it quantum-by-quantum for readout, will grow exponentially with the length of time coherence is needed, and the number of quanta in use. I don't anticipate a qC to be able to crack AES-256 encryption anytime this century, if ever.

I find the middle of the book most useful. Dr. Kaku discusses mechanically enhancing our smarts. This is actually what we do all the time with the academic technologies, beginning with the emergence of writing a few thousand years ago. While we still ought to teach times tables to our youngsters (gigantic groan from the grandkids), calculators in our phones and watches ensure that we make fewer arithmetical blunders. In 1958 "The Feeling of Power" by Asimov was published, in which mental arithmetic is rediscovered after decades during which all calculation was done using small devices (in 1958 the "desk calculator" was a bit bigger than a portable typewriter). These days we use Google or Bing or DuckDuckGo to find stuff we're not quite sure we remember, or don't know in the first place. Siri and other voice apps on our phones make this process simpler than ever. This enhances our useful smarts.

I am not sure most of us will ever need the invasive devices he describes, such as nanowire hookups to our hippocampus and other areas that mediate memory. The mind is tough to tinker with mechanically. TMS (trans-cranial magnetic stimulation), using a magnetic coil outside the skull, can briefly inhibit certain functions. It has been used to make a person a temporary psychopath, by zapping the brain area where caring resides, and to briefly release savant capabilities, by shutting down an area of the brain that is inactive in autistic savants. But TMS does not add capabilities, it only releases inhibitions placed upon some functions in ordinary brains. Why would you want to be a psychopath, anyway? Ask Neil Armstrong, who needed totally uncaring, steely resolve to land the Lunar Module in 1969. Not all psychopaths are criminals. Maybe future lunar missions (or even commercial airliners) will include a TMS device to shut down distracting anxiety in a pilot during landing.

Supposing we learn to read out and implant memories, even to create or erase them at will. Sometimes this could be a very good thing. I define neuroses as "out of date defense mechanisms". The person or situation that hurt someone is gone forever, but they still react to certain stimuli in embarrassing or disabling ways. When a neurosis is based on a well defined, focal experience, psychologists call it an Engram, and erasing engrams might be a very useful future use of mind technology. Other than that, leave my memories alone!

But memory is slippery, and specific incidents don't just make a kind of diary record in some spot in the brain. Dr. Kaku describes well how shortcut/thumbnail images go one place, emotional memories another, smells elsewhere and so forth. Recalling a memory means gathering all these bits back together for replay through some part of the frontal lobe (and relevant spots throughout the brain) so you can relive the incident. But we edit our memories, emphasizing certain items at the expense of others that we gradually forget entirely. This makes "truth serums" unreliable, as discussed in a mind control chapter.

Dr. Kaku discusses the possibility that we might merge with our electronic offspring, once it is to our benefit to do so. This simply expands the notion of "prosthesis" to the brain. Certain modern "artificial legs" actually perform better than the original for specific tasks. Just ask the "blade runner" (and it is unfortunate that he is now a felon; I don't think it likely he knowingly killed the girl but he couldn't convince a jury of that). He wasn't nearly such a fast runner before he got springy metal feet. But he'd need differently designed prostheses to play football (soccer in America).

As I have mentioned many times in earlier posts, I made a 40-year career out of writing software that worked with people, taking advantage of what people to well and leaving to the machine the tasks that people do poorly. A mechanical brain excels at detecting differences. There are amusing puzzles such as "find 10 things that are different between these two pictures". Sometimes, one of the pictures is a mirror image, which to me actually makes it easier. Something that takes experienced puzzle solvers 5-10 minutes would be solved by a computer with a webcam in a second or less. It might also highlight several hundred or thousand tiny errors that arise from printing ink interacting with the fibers in the paper, something few humans would be able to notice without using a microscope. A "wetware" brain excels at detecting similarities. That is why we can see camels or fish in a cloudy sky, or recognize someone from seeing only the edge of a face turned mostly away.

Only in the past week, I noticed that Picasa is picking out faces that are in profile, something it couldn't do before. But it is still flagging a percent or so of things that are clearly not a human face. However, its ability to find 90+% of the faces in my photos really speeds up face tagging. If I give it time after loading a new batch of pix, it gathers suggestions for many of the faces from my library of identifications of about 700 friends in multiple images. This is an example of useful AI: it isn't as good as I am, and doesn't need to be. It just needs to do most of the work and leave it to me for refinement. But I would not want to leave it to the Picasa face-recognizer to guide a drone on a kill mission. Not when it mistakes so many other Asian women for my wife!

A minor error seen in passing on p 255: The fastest supercomputer at the time of writing could perform about 20 PFLOPs (P = Peta), which is explained as 20 trillion; it is actually 20 quadrillion. A trillion FLOPS is a TFLOP (T=Tera).

And, oh dear, another: comets in the Oort cloud are described on p 289 as lying "motionless in empty space". Even at distances up to a light year, these comets move at speeds in the range of at least 100 m/s in orbit about the Sun. Compared to the Earth zipping along at nearly 30 km/s, or even Pluto, averaging about 5 km/s, that is quite slow, but far from "motionless". Autobahn speeds top out near 90 m/s.

Dr. Kaku excels in speculation, which means he is frequently mistaken as his expectations are overtaken by actual events. However, only those who have the courage to predict have the chance of sometimes being right. While the single-processor version of Moore's law was played out about the year 2000, multicore chips and continuing experiments with vertical-transistor chips continue a somewhat more modest trend. Will we ever achieve the 20 PFLOP-at-20-watt processor needed to equal a brain in both speed and power required, and also in volume (2L or less)? Moore's law might suggest the 37-year timeline I figured above, but we can't really know until we try.

And I don't think duplicating human consciousness is a worthy goal anyway. Much better is producing machinery with sufficient computing power to enrich everyone's lives at affordable cost. This matches the old Japanese supercomputer project which had as one goal, achieving Cray-1 capability (100 MFLOPs) in a $2,000 PC by 1995. This goal was achieved. The computer I am using now, which I built, is 100 times that fast, and the parts cost $800. I want machines to continue what they do best: complement and supplement our abilities. I think Dr. Kaku would agree, in spite of his excited, blue-sky forecasts.

The Appendix is titled "Quantum Consciousness?". It is likely that "free will" and full consciousness require quantum uncertainty. Here I am in full agreement. There is quite a discussion of the "Cat in a box" proposed by Schrödinger. Based on a carefully set-up radioactive detector that has exactly a 50% chance of triggering the release of poison gas to kill the cat in the next hour, we are asked, at precisely the one hour point, "Do you think the cat is dead or alive?". Much is made of the meaning of the Observer, in the Copenhagen Interpretation favored by Niels Bohr and most physicists, and other interpretations. No mention is made of the fact that the cat is also an observer! In fact, the results of many experiments that are intended to "prove" these things show that photographic emulsions, CCD detectors and other devices are also observers! They record the "collapsed wave function" phenomena, whether or not a human is present. I think nobody suggests that the image on a piece of film, developed in automatic machinery, does not truly appear until a human actually turns on a light and looks at it.

I think I am repeating something I wrote elsewhere to say this: a beam of light passing through a vacuum is affected by everything it passes, at any distance whatever. Of course, if you pass it through a small hole you'll get a diffraction pattern. The edge of the hole is the "observer" that leads to the scattering of the photons into a more divergent beam. But even a 1mm diameter laser beam, if it passes through a 1 meter aperture, will make a different pattern on a distant film than it would if the aperture were 2 m across. It will also differ if the aperture is square vs round. The existence of "things" in the universe provides an infinite number of "observers", contributing to the collapse of the wave function—if indeed that is what actually happens—for every quantum event everywhere.

Thus, the author's conclusion is apt. We must know ourselves better, not only to enhance or even duplicate our abilities, but to develop tools that work with us in better and better ways, in more and more useful realms of experience.

A mere century's prediction

kw: book reviews, nonfiction, science, physics, predictions

If the future were a thing, I suppose we could do something about it. It is, instead, a process based on contingency, a set of outcomes mostly based on current trends, but subject to black swans. By 2001, according to Arthur Clarke's story "The Sentinel" (1951; adapted into the film 2001, A Space Odyssey in 1968), we would have an established presence on the Moon, a "Space Hilton" in a rotating ring-shaped space station, and the capability to send Hal and his pals in a huge ship to Jupiter (or Saturn in the story).

In 2001, none of this came to pass. We had a generation of college graduates who were born after we stopped going to the moon. One small space station had been allowed to crash to Earth, and another one that is moderately useful but is primarily an embarrassment, and an inwardly-focused Western society that seems ever more likely to be swallowed up by a burgeoning Islamicism that nobody dares to challenge openly. In 2100 AD, will the American constitution have been replaced by Sharia law? If so, science will be at a standstill, and world population will be reducing rapidly as we revert to an economic and political order that arose seven centuries ago among a people not noted for their toleration of new things and new ideas.

If all that doesn't come to pass, and more cosmopolitan values prevail, there is a chance that the dreams of Michio Kaku can come to fruition. Author of Physics of the Future: How Science Will Shape Human Destiny and our Daily Lives by the Year 2100, Dr. Kaku is a professor of theoretical physics. He's had the good fortune to get to know many of the scientists who are creating technologies that, they hope, will craft our future: biotechnology, artificial intelligence, nanotechnology and telecommunications.

I enjoyed reading the book, but came away with the melancholy feeling that it reaches too far, and possibly in the wrong direction. The author does anchor himself in the Cave Man principle: inside, we haven't changed much in 100,000 years. Thus, the first century of the Industrial Revolution may have radically improved life in the West, but it also issued in large-scale warfare, starting with the American Civil War, climaxing in the two World Wars, and winding down in the Cold War. The enemies of Western expansionism have adapted by raising guerrilla warfare to a level that nullifies much of the advantage of our high technology. Of course, society has gotten more soft-hearted (and soft-headed), so that we think losing 4,000 soldiers in two wars in the Middle East is too costly. Just as we thought losing 50,000 in Viet Nam was too costly. We lost 450,000 in Europe from 1942-1945, folks, don't forget. Was it too costly? What was the alternative? And we don't turn a hair at the 38,000 (down from 50,000 a decade earlier) that we lose yearly on American highways. We largely ignore the 100,000 (at least) lost to medical mistakes in American hospitals every single year. But a single soldier's death in Afghanistan is considered a tragedy beyond compare.

OK, what did Dr. Kaku write? He predicts that our grandchildren will have godlike powers. They well may. Will they have the wisdom to use them well? The Internet with its advanced searching strategies is the greatest library ever amassed. The majority of searches are aimed at finding pornography. The Cave Man has his dark secrets. Perhaps the Cave Man ought to be eliminated, but take care what you wish for. It is likely that the Cave Man's unique talents brought us where we are, and cannot be dispensed with if we are to continue to progress. We may not like aggressive behavior, but we may not be able to do without it.

Will we become wiser if the expected life span increases by another factor of two or three (into the range of 200 years or so)? If it is accompanied by an extended youthfulness, will women delay having children until they are in their forties or eighties? Will they be willing to keep having periods another fifty years or so? Biotechnology's promoters are promising all kinds of new cures and bodily enhancements, but they all have one of two aims: longer life or more frequent (and better) sex. Just what the Cave Man wants.

How soon will computers or robots be able to do all those things we've been promised for so long: such as household drudgery, dangerous mining, or underwater salvage? Will they ever be able to produce poetry or sonatas or convincing dialog for the theater? These are two ends of the AI spectrum. There is a little rug-cleaning robot already on the market (for a decade or so now). A few programs like Racter produce interesting, if clumsy, dialog. So far, though, no convincing winner of the Turing Test has arisen. I follow the news about autonomous automobiles that don't need a driver. Their recognition tasks are made easier by the use of GPS, but in the absence of satellite navigation, they don't do as well getting down the road as an average cockroach. And Shakespeare and Bach are as yet secure in their positions. My own take is, human-level AI is at least 1,000 years in our future.

Some medical researchers dream of a day when they can send a small army of "nanobots" into a human body, and have a cancer cured, or a bone fracture healed. Materials scientists hope to turn carbon nanotubes into larger and larger single-molecule structures with the tensile strength of diamond, but manufacturable in sizes ranging up to a 33,000 mile tall space elevator. Others are using "quantum dots" and similarly small particles for all kinds of materials with new properties. Will nanotech allow us to produce a contact lens that contains a computer, and can project an image with high resolution right onto the retina. Can you still call that a computer?

I have been jokingly saying for some years that in the near future, having a cellular phone will be considered a right, and that babies will have a phone implant inserted right behind their ear, shortly after birth. It may not be that much of a joke! Connectivity is a dire necessity for my son's generation.

There are a few things I think are quite unlikely. X-ray vision using specially sensitive goggles and a lot-intensity source of moderately soft x-rays, the kind that usually bounce off one's body rather than pass through. These would be similar to the x-ray backscatter devices now being used at some airports. For all but the most frequent travelers, the extra exposure to x-rays at airports may not be a problem, but if x-ray goggles become a consumer item, I'd expect a huge backlash from two constituencies, the folks who don't want privacy invaded and those who don't want the extra radiation. In another place, it is stated that a solar sail might propel a craft to 0.1% of the speed of light. This is possible. However, then it is stated, "perhaps [it will] reach the nearest star in four hundred years." The nearest star beyond the Sun is 4+ light years away. At 0.1% of the speed of light, reaching it would take more than 4,000 years.

There is a good bit of advice, to get work that a robot cannot perform, work that requires pattern recognition and common sense. So far, these cannot be reliably programmed. I would add creativity. There are no robotic Picassos in our immediate future, and possibly not ever. The book ends with a chapter outlining a possible day in the life, circa 2100 AD. Here is where the author needed a collaborator. He simply isn't a fiction writer, and it shows. The rest of the book is well written by contrast. It gave me a lot to think about, an attribute that I prize greatly.

Staying above water

kw: national debt, predictions

I had some thought of gathering data to make a chart of the monetary trouble the nation is in, but found that others have done so already.

This chart, from this Wikipedia article, is packed with information. Firstly, the shape of the area plot shows how the total National Debt compares with Gross Domestic Product, from 1940 to today. In the Wikipedia article, the author writes that the dates shown are for the end of a Federal fiscal year, so that the 2009 marker at the lower right indicates October 1, 2009, the end of the 2009 fiscal year.

Secondly, the red and blue hues with the name labels show the administration during the years in question. Finally, we see that we are approaching a level of debt not seen since the run-up to World War II. Considering that WW III began nineteen years ago, this is no surprise. The surprise is the level of denial at all levels of government.

On one hand, this is alarming, because we are mortgaging our children's futures. On the other hand, we need to consider an appropriate analogy. What does it mean for national debt to approach 100% of GDP? In family terms, the total federal debt is similar to a family's debt, and the GDP is analogous to the family income.

According to the formula in use prior to about 2002, a bank would evaluate your creditworthiness for a new loan in part by the 25/38 rule: Home mortgage payments must consume no more than 25% of your gross income, and total debt service payments, adding in car loans and credit card payments, must be 38% or less. However, even when home mortgage rates were in the 8% range, just fifteen to twenty years ago (and they have been higher at a few earlier times), the value of the loan was about 11-12 times the yearly payments. Now with 5% money available, the value of a loan is about fifteen times the yearly payments. If a home mortgage is consuming a quarter of your income, then the mortgaged amount is between three and four times your gross income. That is considered a sustainable amount of debt by a conservative banker, and does not count the extra debt that may push the amount of your payments toward 38%. Because car loans have higher interest rates (even if hidden in extra fees so they can claim 0%), and credit card rates are much, much higher, the total debt added is small compared to a mortgage.

In practical terms, the point in my life that my wife and I had the worst debt-to-income ratio, we owned two houses with mortgages totaling $62,000, and had a total income for both of us of just under $30,000. Our debt was more than 200% of our gross income. By contrast, our current debt totals 71% of our gross income. And, as a matter of fact, if we do not pay off our mortgage prior to passing away, the mortgage will be passed on to our son along with the equity in our home; we have in a way mortgaged his future.

Here the analogy breaks down. He can sell the house, which is only about 30% mortgaged at present. He'll have money left over. The Federal government can hardly sell the country to pay off its debts, although in actuality, about $1.1 trillion is held by China of a total of $4.4 trillion or 30% of the federal debt, held in foreign hands. In a sense, we've already sold off 30% of the country! That concerns me more than the total size of the national debt.

So, I am concerned, but the concern is balanced. People whose loans were foreclosed in and after 2007 had been put into situations where they'd borrowed up to six or eight times their total income, with payments that frequently exceeded 50% of their income. That was unsustainable, and if debt service payments reach 50% of federal income, our country will have entered a near-bankrupt condition. We are getting close, and that is the reason behind the S&P action, downgrading the country's credit rating.

AI apostles never give up

kw: computers, artificial intelligence, predictions

Some thirty years ago, when I was an OS analyst for large mainframes and supercomputers, I visited my favorite aunt and uncle. At one point, my uncle asked, "Do you think computers will ever take over the Earth?" I replied, "The already have," and went on to explain how society would fall apart without them. But I also said there is no intentionality; the computers were not agents, but tools, very very fast and powerful tools indeed, but tools.

A few days ago, the June 2010 issue of Scientific American arrived, and I have just read the feature article, "12 Events that will Change Everything". One of the twelve is titled "Machine Self-Awareness" with the subtitle, 'what happens when robots start calling the shots?'. The writer of this piece is Larry Greenemeier. He quotes Hod Lipson of Cornell University, that as machines "get better at learning how to learn" (Greenemeier's phraseology), "I think that leads down the path to consciousness and self-awareness." (Lipsom quote)

To be short about it, I don't. Artificial Intelligence (AI) based on computers has been preached for more than fifty years, and seems no closer now than it was when Eniac was called an Electronic Brain. As it happens, heuristic programming remains as difficult as ever it was, and machine learning is very simple indeed. Remember HAL from 2001: A Space Odyssey? Nearly nothing predicted by Arthur Clarke in that screenplay has emerged, here nine years past that date. A few of the simpler goals of the Japanese Fifth Generation project were achieved, but the widespread adoption of Inference Engines never happened, because such Engines were never brought to fruition.

There is a critical difference between the hardware/software combination we call a computer, and the wetware, the brain/body system, we call an animal mind. The following is true not just of humans but of animals in general: a Mind is really, really good at finding similarities and recognizing familiar things, and really, really bad at numerical calculations and at finding subtle differences and distinctions. And the converse is true of all computational devices: a Computer is really, really good at numerical calculations and manipulations, and at finding subtle differences and distinctions, and really, really bad at finding similarity and at recognition. I have built a career upon this distinction, upon taking advantage of the synergy between a Mind and a Machine (or Computer). A slogan in my profession is "Let the singers sing and the dancers dance."

Self-awareness is hard. It requires a recognition task of the highest order. So far as we know, self-awareness is only found in humans, dogs, chimpanzees, and certain birds. All other animals show no signs of self-concept. Yet it takes only a circuit of three or four neurons in an animal brain to perform recognition tasks that require very sophisticated software in computers. For example, the face-recognition software in Picasa (one of my favorite Google tools), does a workmanlike job, but makes some spectacular blunders. A small fly with its few dozen neurons is as fast and more accurate. Of course, it is so far not possible to couple a fly's brain to an installation of Picasa.

It turns out that the behavior of just three neurons in a circuit is so complex that it takes a large, multi-multicore piece of hardware to run a program that accurately mimics it. Artificial neurons have proven very hard to produce. Let's suppose a true learning machine is one day developed. Upon what will it be based? Probably on some kind of artificial neurons. It will be a kind of artificial animal. What other life-systems must be provided for it to operate correctly?

I suspect that it will need sensory input to keep it sane. Any animal kept for too long in a sensory-deprivation environment becomes unbalanced, sometimes permanently. So, provide senses. Now it needs filters, so it is not overloaded by its senses, but can tune its awareness of them. Finally, you have, perhaps, an artificial cockroach, except it is the size of a lapdog. I hope advances in battery technology give it more than a half hour of operation before recharging is needed.

At that point you have an interesting laboratory curiosity, but cockroaches are easy to breed. Training animals is cheaper than replacing them with such contraptions. So my final contention is that it will never be economical to build a machine that is capable of self-awareness, and keep it running long enough to attain a useful amount of education. I simply don't believe silicon (or other technology) will replace carbon-based life. Ever. Sorry, Berserkers; Sorry, HAL; Sorry, Colossus; even Sorry, Friday (Heinlein's cyborg girl) and all the Borgs out there. You're fun fiction. Fiction you will stay.