Tuesday, February 23, 2010

Daniel Kennefick: Travelling at the Speed of Thought

Daniel Kennefick's Traveling at the Speed of Thought tries to untangle the current state of science with respect to gravitational waves. The approach is mostly historical, with a focus on what Einstein thought at various times, and how others reacted to his analyses. The book is also fairly recent (2007) and doesn't seem to have been eclipsed by new discoveries yet. (There are active experiments looking for physical evidence of gravity waves. The effect is expected to be minuscule, so proponents are bothered by lack of success so far.)

A lot of the story is driven by a referee's report on a paper Einstein and Rosen submitted to Physical Review in 1936. Einstein was apparently used to European deference to authority on submitted papers, and was so upset that an anonymous referee had been consulted that he sent it to an obscure journal. By the time it was published there, Einstein had changed his mind about the primary conclusions.

The primary question seems to be whether gravitational waves carry energy with them as they propagate. If they do, then their sources (black holes, for instance) ought to lose mass over time. If they don't carry energy, then we don't have a sufficient theory of what could be propagating.

Another question that has to be answered is how fast gravity travels, and what it is that moves. In waves in water, individual water molecules only move locally, while the wave can travel great distances. With electromagnetism, actual photons move from place to place, carrying the influence. Which kind of thing is gravity? In one case, we should try to identify the medium in which the disturbance propagates, in the other, we should be able to find the particles themselves.

I may be over-simplifying, but the skeptical viewpoint seems to be that symmetrical motion or ballistic motion of any isolated mass wouldn't radiate energy, since changes in trajectory are required to produce gravity waves. If the present crop of detectors fails to find anything, this may be the best interpretation. It's hard to reconcile this suggestion with the presence of supernovas and binary star collapses. Those seem like dynamic enough changes that they should result in a change in the gravitational field that would have to propagate at some finite velocity.

Kennefick's book provides a good, general introduction to the area, without getting too technical. If you're interested in the history it would make sense to read it. If you're looking for more details on what is know, how the math works, or how to interpret the results from the detectors, you should probably look elsewhere.

Thursday, February 18, 2010

Harry Turtledove: The United States of Atlantis

Harry Turtledove's The United States of Atlantis is the second book of his series of a mythical extra continent in the middle of the North Atlantic Ocean, and how its history progresses parallel to the real North America. The story starts up a decade or two after the close of Opening Atlantis, so the main characters from the end of that book are the focus characters throughout this one. In this book, the British tighten up on taxes and import restrictions until the settlers say enough and start a revolution parallel to the American one. Victor Radcliff, who was pursuing a retirement career as a farmer after the previous novel, is chosen by the rebel Atlantean Assembly as their General. He has to recruit and arm an army, manage his political overseers, and run a campaign against a force that is better armed, better trained, has control of the seas, and is far from home. Of course, Radcliff has all the advantage of knowing the territory, protecting his home, and having the support of (most of) the populace.

The focus follows the military action almost exclusively. The campaigns are reasonably realistic and well told, with each side winning their share, but the eventual outcome is predictable, so it's never a surprise when Radcliff's setbacks are followed by bigger triumphs. The surprising thing to me was there was no attention paid to the events among the Assembly which was attempting to form a government. It seems to me that the possibilities for alternate history in the area of politics are far richer in this time of intellectual and political ferment than for alternate military history. As it was, freedom-related themes are mostly subliminal. We know that the characters are fighting for the independence of their home, and they occasionally talk about their feelings for the British Crown, but they don't talk about liberty, or how to organize or regulate a free society.

Alternate military history, on the other hand, is pretty simple, particularly when the geography and forces aren't constrained to mimic another battle or campaign closely. It's an interesting sequence of fights, and the strategems and tactics employed are interesting, but they don't reflect much on any particular previous war.

This book was nominated for the Prometheus award, and in a weak year it may win. There are hints that the third book in the series (Liberating Atlantis, released in November, so it could be eligible for 2009 or 2010) might be much stronger. Of the nominees that I've read, The Unincorporated Man is the only one that I like more for the Prometheus award.

Tuesday, February 16, 2010

Steven-Elliot Altman and Diane DeKelb-Rittenhouse: The Killswitch Review

Steven-Elliot Altman and Diane DeKelb-Rittenhouse's The Killswitch Review is a heavy-handed diatribe against government control of death and dying. In the year 2156, stem cell therapy and other advances make it technically feasible to extend lifespans indefinitely. But a malthusian economy makes it necessary to restrict the technology to Conscientious Citizens, and to control access to suicide at the same time.

The Killswitch of the title is a technology introduced by the government to allow a painless suicide, and record the context to ensure that nothing nefarious is involved. Jason Haggerty works for the agency that reviews the records. Anyone over thirty can request a Killswitch--access is forbidden to minors. (And as usual, they want access as a sign of their maturity.)

The society is so depressing that people who could live indefinitely do kill themselves, and people with no hope want to do the same. For some reason, the authorities want to prevent the latter, while society suffers from overpopulation and many forms of ecological catastrophe.

The story follows Jason as he and his sidekick android track a public suicide that may not have been what it seemed. They find conspiracies, speakeasy torture parlors, freedom fighters toiling in the wilderness, and of course, the richest man in the world is responsible for the plot.

For me, the story never overcame the premise. A future in which people are a burden, only the well-connected have access to longevity treatments, but they aren't sure they want them, and masses of young people who are unemployed, bored, and forbidden access to anything that might give them a way out. Bleah.

Friday, February 05, 2010

Kwedit: payment for virtual goods

The most interesting new E-Commerce play that I've heard of in at least 15 years is Kwedit.com. Last fall, a friend was sounding me out about a consulting opportunity, and told me what his company was up to. My reaction was "I'll do it if you pay me at least half in equity." We weren't able to work out terms before they found a different way to solve the problem I might have helped them with, but I haven't been able to talk about the company and what they're doing until now. They're building a payment system based on credit for virtual goods. That combination lets them tell the publishers that there's no need to eliminate fraud--as long as customers have enough incentive to pay that it leads to incremental revenue, you can stop worrying about the customers who don't pay. People who run up their "kwedit" account in a virtual world building up a character aren't going to want to abandon their character, and in order to continue using it, they'll have to settle the bill. The other amazing thing Kwedit has done is to figure out lots of ways to let people pay. By making it straightforward for people without credit cards or checking accounts to pay, they'll be tapping into a vast, under-served market. Their biggest coup to date is that they have 7-11 signed on as a major partner. You can take your outstanding kwedit balance, print out a bar code (or maybe download it to your smart phone) and take that to a 7-11 store, where you'll be able to pay for it, just like it was an item on their shelves. Users can also send cash or a check in a business reply envelope they print themselves or have a friend or parent pay the bill using a credit card. With this payment mechanism, Kwedit doesn't need any strong identity guarantees for their customers. You can create a pseudonymous account, and as long as your kwedit account keeps getting paid off, no one else has to know who you are. They went live on Wednesday, and have had some favorable press. I think they've got a better chance of making this work than anyone else in the payments space. It's a sub-market, but I think it's one that no one else is targeting.

Thursday, February 04, 2010

J. Storrs Hall: Beyond AI

J. Storrs Hall (JoSH)'s Beyond AI provides a good and thorough introduction to the issues surrounding AI. I had expected JoSH to try to explain how to build an AI, and to fail at that, because no one really knows what the necessary breakthroughs will be. I expected that because I've known him long enough to know that he's a smart, ambitious guy who's thoroughly familiar with AI, who doesn't seem to have been drawn into the debates and discussion about "friendly AI". But he surprised me by writing a very readable, very useful book that doesn't say much that is new, but organizes it in a way that lays out the important issues in context and gives a road map for how we can learn to deal with the changes that development of smarter than human AI will bring to our world.

After a brief dip into dreams from antiquity of creating artificial creatures and how they were expected to change the world, JoSH starts the technical history with feedback theory and cybernetics, and shows how those evolved into control theory, information theory, and neural networks. He then shows where his roots are with a section titled "The Golden Age" that talks about work on symbolic AI through the 60s and 70s. This led to what looked like rapid progress and solutions to a number of problems: competence in various microworlds, rudimentary ability to generate understandable language, ability to understand constrained language, and promising representations for abstract knowledge. This is followed by a chapter that shows how the pioneers became disillusioned with their approaches by the end of the 1970s, as they harnessed their tools to solve a wider variety of problems, but discovered that they weren't solving harder problems, or finding any approaches that were leading to general mastery.

Any particular problem area could apparently be analyzed and reduced to a mechanical solution, but that solution didn't seem to help with the next one. JoSH attributes the stumble to the fact that the early approaches relied on programmers explicitly coding specific knowledge about each domain into an architecture organized around a formal model of the domain. This works for a constrained area, but leaves no room for fuzzy boundary cases. People are good at interpreting definitions and instructions loosely and knowing when to do so, but a program that can diagram sentences and summarize a typical daily newspaper would be useless if you wanted to translate the user's manual for a consumer appliance, or generate route instructions for a navigation application.

The next part of the book addresses the nature of mind: what general intelligence is, and what it would take to build something that could understand itself well enough to enhance its own functioning. JoSH draws together evolution (in E. O. Wilson's Sociobiology), with advances in computing and philosophy. Researchers in the 90s were explaining how the mind is made of separate modules that we can analyze in isolation, and whose distinct failures can be seen in identifiable mental disorders. When artificial minds are contemplated from that point of view, the problem of building one to suit appears more tractable, and the idea of recursive self improvement becomes more manageable. In our own brains, it's clear that there are distinct modules with separate responsibilities, that when one part becomes damaged, other brain regions can provide substitutes for the functionality at a reduced efficiency, and that the modules communicate with one another in some flexible way rather than relying on formal, precise interfaces. That makes it easier to believe that an artificial mind, built modularly, could use its understanding to upgrade and improve itself.

One way to resolve the issue that symbolic AI faced, that their representations were only useful in the verbal domain, and not in the physical has been addressed by the modern embodied approach. There has been a lot more focus recently on building robots that interact with the world to build up their model of their environment. This is a start on figuring out how learning works, and one of the discoveries is that agents interacting with the physical world can often get by with much less internal representation that earlier generations expected. The physical world provides a local representation of itself which, if you can interpret it, can answer many of the questions that arise when you need them. This simplifies the learning and doesn't require as much one-on-one training as building a formal model. It also seems to have been particularly robust, where the formal approaches were brittle. These embodied agents have also provided a more situated environment for re-exploring earlier lessons on reasoning and Bayesian inference. If the robot has to be able to adapt to a variety of different locations, then you're better off giving it the ability to become familiar with wherever it ends up than if it can't do anything until someone explains where the doors are and which outlets its supposed to use.

JoSH spends a chapter outlining an approach based on reasoning by analogy with its own history. It reminds me of Jeff Hawkins' description of how the brain works in his book On Intelligence, but he doesn't go into much detail. It's one part of what will be needed, but the situated AI work will provide many more pertinent clues.

The last third of Beyond AI focuses on social consequences. First: what, who, where and, when, then the questions of free will, what morality should apply and whether it will be friendly to us, and finally whether there will be a singularity, and if so, which one. JoSH identifies four approaches that might lead to different WHAT answers: direct synthesis of AI software, emulation of the human brain at the neural or at some higher level, or building a learning machine that grows up to be a full AI. As far as WHO will win the race, JoSH identifies the military, university and industrial labs, and start-ups and the open source community as contenders, without giving any of them an edge. When he addresses WHERE the breakthrough is likely to take place, he tips his hand as to the shape he expects it to take.

Given the international nature of both the scientific community and the Internet, however, [...] The answer is most likely, everywhere.

As to WHEN, his slow projection is for everything except human-level flexibility and creativity by 2025, and 2035 for general human equivalence. With a few key breakthroughs, he thinks that general human equivalence could arrive in the 2020s.

JoSH does an unusually good job of explaining why free will isn't a problem. First of all, I want to point out that he laid the groundwork earlier by talking about how we understand gravity in order to be able to forestall a crucial objection in the middle without requiring a long aside. The whole book seems to have been constructed this way, with explanations early on that help reduce confusions later without seeming out of place when they occur. As he presents it, the problem is that we have a strong intuition that there's some contradiction between the deterministic nature of the universe and our ability to make choices that change the way things will turn out. JoSH points out that in order to make predictions about how our behavior will affect things, we have to have a mental model that includes a deterministic world which we inhabit, but that our model of ourselves has to be one that shows us making choices. We have to think of ourselves as considering alternatives and evaluating them and then making a choice. (When we're sophisticated, the models show that other people are also making choices) Given that the mental model allows us to make decisions, it has to have those two parts. Even if everything is deterministic, the self-model has to consider different possibilities before choosing actions. That part can't feel deterministic if it is to succeed as a model. That's all free will is.

The conclusions reached in Beyond AI about the ultimate shape of the future are remarkable similar to my own. Change will be large, but will arrive gradually, and there won't be any dominating breakthroughs. Many people will develop many different systems that advance the state of the art along a broad front. The groups best able to take advantage of other people's work will be working in the open and sharing their results. In this kind of environment, the best way to exploit your advancement is to bring it into the market place. AIs that emerge in this kind of context will see that cooperation with others and competition to best serve customers and provide value is the best way to get ahead. This kind of morality will serve them, and will lead them to be friendly in the important sense. Just as Adam Smith explained in his Invisible Hand metaphor, they'll help us (their customers) because that's the best way to advance their own interests.