Monday, May 26, 2008

From eyeglasses to cybernetic eyes, and beyond

kw: book reviews, nonfiction, science journalism, technology

People's ideas of robots is most recently influenced by the Wil Smith film, I, Robot. Though the title is from Isaac Asimov, the theme is due more to Jack Williamson, who foresaw robots becoming our nannies, to a pathological extreme, in his story "With Folded Hands". Really, though, where is robo-technology going?

"The future promises a wealth of humanlike machines and machinelike humans," declare Gregory Benford and Elisabeth Malartre in Beyond Human: Living with Robots and Cyborgs. The viewpoint is that robotic and cyborganic technologies are tools, with more "smarts" built into them, perhaps, but no more innately good or evil than are eyeglasses, hearing aids, pacemakers, or titanium knee replacement joints.

The authors survey the spectrum, beginning with "Man Plus", which indeed includes eyeglasses and not just hearing aids but lens- and cochlear implants, and trends inevitably toward, perhaps, the brain getting either a "body transplant" or a mechanical body, à la Robocop. Is there a line somewhere beyond which the person ceases to exist? Or is it somewhere between Robocop and the "downloaded personality", in which the brain also is an artifact? Or is there no line? They make their position clear that a bodiless brain/mind has no meaning; our bodily functions and emotions are essential to our mental functioning, even though at times they may seem to hinder it.

They then survey the field of "Robots Plus", the spectrum from industrial welding robots, in use by the thousands, to humanoid, or rather "mammaloid", types, including Honda's Asimo and various robotic pet dogs. There is quite a bit of sociological musing here, with the conclusion that while it is necessary that some robots appear to be human, there is the danger of people imputing too much humanity where it isn't deserved. We're all to willing to lean 'way over backward to "help" a mechanism seem to pass the Turing Test.

I am reminded of a simple computer program I wrote, based on a story I read. It answers questions with Yes or No, implying a 20-questions game. After the fifth Yes answer, it asks "Is that it?" If the user enters Yes, it goes on to "Start Over?" People who play it express amazement at the database that must underlie its ability to guess their hidden thought, when they actually supply nearly everything themselves. One version of the game simply answers Yes every time the last letter is an E; others use a slightly more complex calculation (number of vowels, perhaps). But those who use it find themselves thinking it has great abilities.

The third part of Beyond Human explores the middle ground, a meeting place as it were between mechanism and human. At this point I began to do some calculations. All who viewed I, Robot were impressed with the power and speed of the malicious robots, even though it was found that most of their brain power was at the other end of a radio link. Just how quick and strong can a robot be?

The heavy welding arms in factories are known to be dangerous. They don't sense their surroundings, and a few techs have been injured or killed when one swept an arm through a space that is ordinarily free of human obstructions. But they are attached to and driven by heavy machinery "below deck", and the entire mechanism is the size of an auto. What are the physical limits of an autonomous robot?

A human athlete weighing 75 kg has a basal metabolism of about 75 watts, or 1550 Kcal/day (the nutrition "calorie" is a Kilocalorie). During heavy stress, such as a bicycle race, or lumberjacking, a trained person can exert 700 kcal/hr (about 800 watts, or one horsepower) for extended periods. An athlete in training can carbo-load before a major event such as a marathon, to gain a "quick reserve" of 8,000 kcal or more. The athlete's fat reserves total another 30,000 to 50,000 kcal. The entire energy system uses about 60% of one's body weight, or 45 kg for this athlete. To put these into electrical terms, 8,000 kcal = 9,300 watt-hours, and a 40,000 kcal reserve equals 46,500 w-h.

The two best battery technologies available, Li-ion and Li-thio-chloride (LTC), can store 128 and 700 w-h per kg, respectively, though the latter cannot sustain rapid discharge. An experimental technology by Nanoexa exhibits storage density of 3,000 w-h per kg, using nanotechnology to increase the efficiency. This last implies that a 3 kg battery could store the energy found in a fit person's fat reserves. If Li-ion is needed for faster discharge, however, the mass requirement is 360 kg. Even the "carbo-load" reserve requires 75 kg of Li-ion batteries. More to the point, just keeping a human body alive for a day uses the energy found in 15 kg of Li-ion batteries.

Perhaps we need to think of other types of animals. A 75-kg American Alligator has only 1/25 the resting energy need of a human (about 3 watts). That is why they can stay underwater for so long, while we can barely stand to hold our breath for one minute. Having a small heart, and modest short-term reserves of glycogen, Alligators work best when they can work in short spurts, so they are ambush predators. Not for them the Cheetah's run or the Bear's charge. A mechanical alligator could do short spurts of energetic work, but would need a powered umbilical for sustained effort, an option people don't have.

But the power-to-weight ratios of smaller bodies are even more unfavorable. Much is made of "robotic insects" for surveillance. A crawler and wall-climber might work out, but a flying robo-bug simply can't carry enough energy to stay aloft more than a second or two. It makes more sense to use an ultra-small "critter cam" attached to a Cicada or large fly.

Finally, the authors bring out a point that few science fiction writers ever consider: The marketplace will decide what sells. The technologies available forty years from now will be those that pass the market and utility tests. Robots for sale in 2048 will be robots people like, and enhanced humans cannot be too obvious, or they will suffer from the "green monkey" syndrome and be shunned.

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