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Tuesday, September 13, 2016

Reading List: The Age of Em

Hanson, Robin. The Age of Em. Oxford: Oxford University Press, 2016. ISBN 978-0-19-875462-6.
Many books, both fiction and nonfiction, have been devoted to the prospects for and consequences of the advent of artificial intelligence: machines with a general cognitive capacity which equals or exceeds that of humans. While machines have already surpassed the abilities of the best humans in certain narrow domains (for example, playing games such as chess or go), you can't take a chess playing machine and expect it to be even marginally competent at a task as different as driving a car or writing a short summary of a newspaper story—things most humans can do with a little experience. A machine with “artificial general intelligence” (AGI) would be as adaptable as humans, and able with practice to master a wide variety of skills.

The usual scenario is that continued exponential progress in computing power and storage capacity, combined with better understanding of how the brain solves problems, will eventually reach a cross-over point where artificial intelligence matches human capability. But since electronic circuitry runs so much faster than the chemical signalling of the brain, even the first artificial intelligences will be able to work much faster than people, and, applying their talents to improving their own design at a rate much faster than human engineers can work, will result in an “intelligence explosion”, where the capability of machine intelligence runs away and rapidly approaches the physical limits of computation, far surpassing human cognition. Whether the thinking of these super-minds will be any more comprehensible to humans than quantum field theory is to a goldfish and whether humans will continue to have a place in this new world and, if so, what it may be, has been the point of departure for much speculation.

In the present book, Robin Hanson, a professor of economics at George Mason University, explores a very different scenario. What if the problem of artificial intelligence (figuring out how to design software with capabilities comparable to the human brain) proves to be much more difficult than many researchers assume, but that we continue to experience exponential growth in computing and our ability to map and understand the fine-scale structure of the brain, both in animals and eventually humans? Then some time in the next hundred years (and perhaps as soon as 2050), we may have the ability to emulate the low-level operation of the brain with an electronic computing substrate. Note that we need not have any idea how the brain actually does what it does in order to do this: all we need to do is understand the components (neurons, synapses, neurotransmitters, etc.) and how they're connected together, then build a faithful emulation of them on another substrate. This emulation, presented with the same inputs (for example, the pulse trains which encode visual information from the eyes and sound from the ears), should produce the same outputs (pulse trains which activate muscles, or internal changes within the brain which encode memories).

Building an emulation of a brain is much like reverse-engineering an electronic device. It's often unnecessary to know how the device actually works as long as you can identify all of the components, their values, and how they're interconnected. If you re-create that structure, even though it may not look anything like the original or use identical parts, it will still work the same as the prototype. In the case of brain emulation, we're still not certain at what level the emulation must operate nor how faithful it must be to the original. This is something we can expect to learn as more and more detailed emulations of parts of the brain are built. The Blue Brain Project set out in 2005 to emulate one neocortical column of the rat brain. This goal has now been achieved, and work is progressing both toward more faithful simulation and expanding the emulation to larger portions of the brain. For a sense of scale, the human neocortex consists of about one million cortical columns.

In this work, the author assumes that emulation of the human brain will eventually be achieved, then uses standard theories from the physical sciences, economics, and social sciences to explore the consequences and characteristics of the era in which emulations will become common. He calls an emulation an “em”, and the age in which they are the dominant form of sentient life on Earth the “age of em”. He describes this future as “troublingly strange”. Let's explore it.

As a starting point, assume that when emulation becomes possible, we will not be able to change or enhance the operation of the emulated brains in any way. This means that ems will have the same memory capacity, propensity to forget things, emotions, enthusiasms, psychological quirks and pathologies, and all of the idiosyncrasies of the individual human brains upon which they are based. They will not be the cold, purely logical, and all-knowing minds which science fiction often portrays artificial intelligences to be. Instead, if you know Bob well, and an emulation is made of his brain, immediately after the emulation is started, you won't be able to distinguish Bob from Em-Bob in a conversation. As the em continues to run and has its own unique experiences, it will diverge from Bob based upon them, but, we can expect much of its Bob-ness to remain.

But simply by being emulations, ems will inhabit a very different world than humans, and can be expected to develop their own unique society which differs from that of humans at least as much as the behaviour of humans who inhabit an industrial society differs from hunter-gatherer bands of the Paleolithic. One key aspect of emulations is that they can be checkpointed, backed up, and copied without errors. This is something which does not exist in biology, but with which computer users are familiar. Suppose an em is about to undertake something risky, which might destroy the hardware running the emulation. It can simply make a backup, store it in a safe place, and if disaster ensues, arrange to have to the backup restored onto new hardware, picking up right where it left off at the time of the backup (but, of course, knowing from others what happened to its earlier instantiation and acting accordingly). Philosophers will fret over whether the restored em has the same identity as the one which was destroyed and whether it has continuity of consciousness. To this, I say, let them fret; they're always fretting about something. As an engineer, I don't spend time worrying about things I can't define, no less observe, such as “consciousness”, “identity”, or “the soul”. If I did, I'd worry about whether those things were lost when undergoing general anaesthesia. Have the wisdom teeth out, wake up, and get on with your life.

If you have a backup, there's no need to wait until the em from which it was made is destroyed to launch it. It can be instantiated on different hardware at any time, and now you have two ems, whose life experiences were identical up to the time the backup was made, running simultaneously. This process can be repeated as many times as you wish, at a cost of only the processing and storage charges to run the new ems. It will thus be common to capture backups of exceptionally talented ems at the height of their intellectual and creative powers so that as many can be created as the market demands their services. These new instances will require no training, but be able to undertake new projects within their area of knowledge at the moment they're launched. Since ems which start out as copies of a common prototype will be similar, they are likely to understand one another to an extent even human identical twins do not, and form clans of those sharing an ancestor. These clans will be composed of subclans sharing an ancestor which was a member of the clan, but which diverged from the original prototype before the subclan parent backup was created.

Because electronic circuits run so much faster than the chemistry of the brain, ems will have the capability to run over a wide range of speeds and probably will be able to vary their speed at will. The faster an em runs, the more it will have to pay for the processing hardware, electrical power, and cooling resources it requires. The author introduces a terminology for speed where an em is assumed to run around the same speed as a human, a kilo-em a thousand times faster, and a mega-em a million times faster. Ems can also run slower: a milli-em runs 1000 times slower than a human and a micro-em at one millionth the speed. This will produce a variation in subjective time which is entirely novel to the human experience. A kilo-em will experience a century of subjective time in about a month of objective time. A mega-em experiences a century of life about every hour. If the age of em is largely driven by a population which is kilo-em or faster, it will evolve with a speed so breathtaking as to be incomprehensible to those who operate on a human time scale. In objective time, the age of em may only last a couple of years, but to the ems within it, its history will be as long as the Roman Empire. What comes next? That's up to the ems; we cannot imagine what they will accomplish or choose to do in those subjective millennia or millions of years.

What about humans? The economics of the emergence of an em society will be interesting. Initially, humans will own everything, but as the em society takes off and begins to run at least a thousand times faster than humans, with a population in the trillions, it can be expected to create wealth at a rate never before experienced. The economic doubling time of industrial civilisation is about 15 years. In an em society, the doubling time will be just 18 months and potentially much faster. In such a situation, the vast majority of wealth will be within the em world, and humans will be unable to compete. Humans will essentially be retirees, with their needs and wants easily funded from the proceeds of their investments in initially creating the world the ems inhabit. One might worry about the ems turning upon the humans and choosing to dispense with them but, as the author notes, industrial societies have not done this with their own retirees, despite the financial burden of supporting them, which is far greater than will be the case for ems supporting human retirees.

The economics of the age of em will be unusual. The fact that an em, in the prime of life, can be copied at almost no cost will mean that the supply of labour, even the most skilled and specialised, will be essentially unlimited. This will drive the compensation for labour down to near the subsistence level, where subsistence is defined as the resources needed to run the em. Since it costs no more to create a copy of a CEO or computer technology research scientist than a janitor, there will be a great flattening of pay scales, all settling near subsistence. But since most ems will live mostly in virtual reality, subsistence need not mean penury: most of their needs and wants will not be physical, and will cost little or nothing to provide. Wouldn't it be ironic if the much-feared “robot revolution” ended up solving the problem of “income inequality”? Ems may have a limited useful lifetime to the extent they inherit the human characteristic of the brain having greatest plasticity in youth and becoming increasingly fixed in its ways with age, and consequently less able to innovate and be creative. The author explores how ems may view death (which for an em means being archived and never re-instantiated) when there are myriad other copies in existence and new ones being spawned all the time, and how ems may choose to retire at very low speed and resource requirements and watch the future play out a thousand times or faster than a human can.

This is a challenging and often disturbing look at a possible future which, strange as it may seem, violates no known law of science and toward which several areas of research are converging today. The book is simultaneously breathtaking and tedious. The author tries to work out every aspect of em society: the structure of cities, economics, law, social structure, love, trust, governance, religion, customs, and more. Much of this strikes me as highly speculative, especially since we don't know anything about the actual experience of living as an em or how we will make the transition from our present society to one dominated by ems. The author is inordinately fond of enumerations. Consider this one from chapter 27.

These include beliefs, memories, plans, names, property, cooperation, coalitions, reciprocity, revenge, gifts, socialization, roles, relations, self-control, dominance, submission, norms, morals, status, shame, division of labor, trade, law, governance, war, language, lies, gossip, showing off, signaling loyalty, self-deception, in-group bias, and meta-reasoning.

But for all its strangeness, the book amply rewards the effort you'll invest in reading it. It limns a world as different from our own as any portrayed in science fiction, yet one which is a plausible future that may come to pass in the next century, and is entirely consistent with what we know of science. It raises deep questions of philosophy, what it means to be human, and what kind of future we wish for our species and its successors. No technical knowledge of computer science, neurobiology, nor the origins of intelligence and consciousness is assumed; just a willingness to accept the premise that whatever these things may be, they are independent of the physical substrate upon which they are implemented.

Posted at September 13, 2016 14:19