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Tuesday, September 27, 2016

Reading List: Idea Makers

Wolfram, Stephen. Idea Makers. Champaign, IL: Wolfram Media, 2016. ISBN 978-1-57955-003-5.
I first met Stephen Wolfram in 1988. Within minutes, I knew I was in the presence of an extraordinary mind, combined with intellectual ambition the likes of which I had never before encountered. He explained that he was working on a system to automate much of the tedious work of mathematics—both pure and applied—with the goal of changing how science and mathematics were done forever. I not only thought that was ambitious; I thought it was crazy. But then Stephen went and launched Mathematica and, twenty-eight years and eleven major releases later, his goal has largely been achieved. At the centre of a vast ecosystem of add-ons developed by his company, Wolfram Research, and third parties, it has become one of the tools of choice for scientists, mathematicians, and engineers in numerous fields.

Unlike many people who founded software companies, Wolfram never took his company public nor sold an interest in it to a larger company. This has allowed him to maintain complete control over the architecture, strategy, and goals of the company and its products. After the success of Mathematica, many other people, and I, learned to listen when Stephen, in his soft-spoken way, proclaims what seems initially to be an outrageously ambitious goal. In the 1990s, he set to work to invent A New Kind of Science: the book was published in 2002, and shows how simple computational systems can produce the kind of complexity observed in nature, and how experimental exploration of computational spaces provides a new path to discovery unlike that of traditional mathematics and science. Then he said he was going to integrate all of the knowledge of science and technology into a “big data” language which would enable knowledge-based computing and the discovery of new facts and relationships by simple queries short enough to tweet. Wolfram Alpha was launched in 2009, and Wolfram Language in 2013. So when Stephen speaks of goals such as curating all of pure mathematics or discovering a simple computational model for fundamental physics, I take him seriously.

Here we have a less ambitious but very interesting Wolfram project. Collected from essays posted on his blog and elsewhere, he examines the work of innovators in science, mathematics, and industry. The subjects of these profiles include many people the author met in his career, as well as historical figures he tries to get to know through their work. As always, he brings his own unique perspective to the project and often has insights you'll not see elsewhere. The people profiled are:

Many of these names are well known, while others may elicit a “who?” Solomon Golomb, among other achievements, was a pioneer in the development of linear-feedback shift registers, essential to technologies such as GPS, mobile phones, and error detection in digital communications. Wolfram argues that Golomb's innovation may be the most-used mathematical algorithm in history. It's a delight to meet the pioneer.

This short (250 page) book provides personal perspectives on people whose ideas have contributed to the intellectual landscape we share. You may find the author's perspectives unusual, but they're always interesting, enlightening, and well worth reading.

Posted at 19:39 Permalink

Wednesday, September 21, 2016

Reading List: Into the Black

White, Rowland. Into the Black. New York: Touchstone, 2016. ISBN 978-1-5011-2362-7.
On April 12, 1981, coincidentally exactly twenty years after Yuri Gagarin became the first man to orbit the Earth in Vostok 1, the United States launched one of the most ambitious and risky manned space flights ever attempted. The flight of Space Shuttle Orbiter Columbia on its first mission, STS-1, would be the first time a manned spacecraft was launched with a crew on its first flight. (All earlier spacecraft were tested in unmanned flights before putting a crew at risk.) It would also be the first manned spacecraft to be powered by solid rocket boosters which, once lit, could not be shut down but had to be allowed to burn out. In addition, it would be the first flight test of the new Space Shuttle Main Engines, the most advanced and high performance rocket engines ever built, which had a record of exploding when tested on the ground. The shuttle would be the first space vehicle to fly back from space using wings and control surfaces to steer to a pinpoint landing. Instead of a one-shot ablative heat shield, the shuttle was covered by fragile silica tiles and reinforced carbon-carbon composite to protect its aluminium structure from reentry heating which, without thermal protection, would melt it in seconds. When returning to Earth, the shuttle would have to maneuver in a hypersonic flight regime in which no vehicle had ever flown before, then transition to supersonic and finally subsonic flight before landing. The crew would not control the shuttle directly, but fly it through redundant flight control computers which had never been tested in flight. Although the orbiter was equipped with ejection seats for the first four test flights, they could only be used in a small part of the flight envelope: for most of the mission everything simply had to work correctly for the ship and crew to return safely. Main engine start—ignition of the solid rocket boosters—and liftoff!

Even before the goal of landing on the Moon had been accomplished, it was apparent to NASA management that no national consensus existed to continue funding a manned space program at the level of Apollo. Indeed, in 1966, NASA's budget reached a peak which, as a fraction of the federal budget, has never been equalled. The Saturn V rocket was ideal for lunar landing missions, but expended each mission, was so expensive to build and operate as to be unaffordable for suggested follow-on missions. After building fifteen Saturn V flight vehicles, only thirteen of which ever flew, Saturn V production was curtailed. With the realisation that the “cost is no object” days of Apollo were at an end, NASA turned its priorities to reducing the cost of space flight, and returned to a concept envisioned by Wernher von Braun in the 1950s: a reusable space ship.

You don't have to be a rocket scientist or rocket engineer to appreciate the advantages of reusability. How much would an airline ticket cost if they threw away the airliner at the end of every flight? If space flight could move to an airline model, where after each mission one simply refueled the ship, performed routine maintenance, and flew again, it might be possible to reduce the cost of delivering payload into space by a factor of ten or more. But flying into space is much more difficult than atmospheric flight. With the technologies and fuels available in the 1960s (and today), it appeared next to impossible to build a launcher which could get to orbit with just a single stage (and even if one managed to accomplish it, its payload would be negligible). That meant any practical design would require a large booster stage and a smaller second stage which would go into orbit, perform the mission, then return.

Initial design concepts envisioned a very large (comparable to a Boeing 747) winged booster to which the orbiter would be attached. At launch, the booster would lift itself and the orbiter from the pad and accelerate to a high velocity and altitude where the orbiter would separate and use its own engines and fuel to continue to orbit. After separation, the booster would fire its engines to boost back toward the launch site, where it would glide to a landing on a runway. At the end of its mission, the orbiter would fire its engines to de-orbit, then reenter the atmosphere and glide to a landing. Everything would be reusable. For the next mission, the booster and orbiter would be re-mated, refuelled, and readied for launch.

Such a design had the promise of dramatically reducing costs and increasing flight rate. But it was evident from the start that such a concept would be very expensive to develop. Two separate manned spacecraft would be required, one (the booster) much larger than any built before, and the second (the orbiter) having to operate in space and survive reentry without discarding components. The orbiter's fuel tanks would be bulky, and make it difficult to find room for the payload and, when empty during reentry, hard to reinforce against the stresses they would encounter. Engineers believed all these challenges could be met with an Apollo era budget, but with no prospect of such funds becoming available, a more modest design was the only alternative.

Over a multitude of design iterations, the now-familiar architecture of the space shuttle emerged as the only one which could meet the mission requirements and fit within the schedule and budget constraints. Gone was the flyback booster, and with it full reusability. Two solid rocket boosters would be used instead, jettisoned when they burned out, to parachute into the ocean and be fished out by boats for refurbishment and reuse. The orbiter would not carry the fuel for its main engines. Instead, it was mounted on the side of a large external fuel tank which, upon reaching orbit, would be discarded and burn up in the atmosphere. Only the orbiter, with its crew and payload, would return to Earth for a runway landing. Each mission would require either new or refurbished solid rocket boosters, a new external fuel tank, and the orbiter.

The mission requirements which drove the design were not those NASA would have chosen for the shuttle were the choice theirs alone. The only way NASA could “sell” the shuttle to the president and congress was to present it as a replacement for all existing expendable launch vehicles. That would assure a flight rate sufficient to achieve the economies of scale required to drive down costs and reduce the cost of launch for military and commercial satellite payloads as well as NASA missions. But that meant the shuttle had to accommodate the large and heavy reconnaissance satellites which had been launched on Titan rockets. This required a huge payload bay (15 feet wide by 59 feet long) and a payload to low Earth orbit of 60,000 pounds. Further Air Force requirements dictated a large cross-range (ability to land at destinations far from the orbital ground track), which in turn required a hot and fast reentry very demanding on the thermal protection system.

The shuttle represented, in a way, the unification of NASA with the Air Force's own manned space ambitions. Ever since the start of the space age, the Air Force sought a way to develop its own manned military space capability. Every time it managed to get a program approved: first Dyna-Soar and then the Manned Orbiting Laboratory, budget considerations and Pentagon politics resulted in its cancellation, orphaning a corps of highly-qualified military astronauts with nothing to fly. Many of these pilots would join the NASA astronaut corps in 1969 and become the backbone of the early shuttle program when they finally began to fly more than a decade later.

All seemed well on board. The main engines shut down. The external fuel tank was jettisoned. Columbia was in orbit. Now weightless, commander John Young and pilot Bob Crippen immediately turned to the flight plan, filled with tasks and tests of the orbiter's systems. One of their first jobs was to open the payload bay doors. The shuttle carried no payload on this first flight, but only when the doors were open could the radiators that cooled the shuttle's systems be deployed. Without the radiators, an emergency return to Earth would be required lest electronics be damaged by overheating. The doors and radiators functioned flawlessly, but with the doors open Young and Crippen saw a disturbing sight. Several of the thermal protection tiles on the pods containing the shuttle's maneuvering engines were missing, apparently lost during the ascent to orbit. Those tiles were there for a reason: without them the heat of reentry could melt the aluminium structure they protected, leading to disaster. They reported the missing tiles to mission control, adding that none of the other tiles they could see from windows in the crew compartment appeared to be missing.

The tiles had been a major headache during development of the shuttle. They had to be custom fabricated, carefully applied by hand, and were prone to falling off for no discernible reason. They were extremely fragile, and could even be damaged by raindrops. Over the years, NASA struggled with these problems, patiently finding and testing solutions to each of them. When STS-1 launched, they were confident the tile problems were behind them. What the crew saw when those payload bay doors opened was the last thing NASA wanted to see. A team was set to analysing the consequences of the missing tiles on the engine pods, and quickly reported back that they should pose no problem to a safe return. The pods were protected from the most severe heating during reentry by the belly of the orbiter, and the small number of missing tiles would not affect the aerodynamics of the orbiter in flight.

But if those tiles were missing, mightn't other tiles also have been lost? In particular, what about those tiles on the underside of the orbiter which bore the brunt of the heating? If some of them were missing, the structure of the shuttle might burn through and the vehicle and crew would be lost. There was no way for the crew to inspect the underside of the orbiter. It couldn't be seen from the crew cabin, and there was no way to conduct an EVA to examine it. Might there be other, shall we say, national technical means, of inspecting the shuttle in orbit? Now STS-1 truly ventured into the black, a story never told until many years after the mission and documented thoroughly for a popular audience here for the first time.

In 1981, ground-based surveillance of satellites in orbit was rudimentary. Two Department of Defense facilities, in Hawaii and Florida, normally used to image Soviet and Chinese satellites, were now tasked to try to image Columbia in orbit. This was a daunting task: the shuttle was in a low orbit, which meant waiting until an orbital pass would cause it to pass above one of the telescopes. It would be moving rapidly so there would be only seconds to lock on and track the target. The shuttle would have to be oriented so its belly was aimed toward the telescope. Complicating the problem, the belly tiles were black, so there was little contrast against the black of space. And finally, the weather had to cooperate: without a perfectly clear sky, there was no hope of obtaining a usable image. Several attempts were made, all unsuccessful.

But there were even deeper black assets. The National Reconnaissance Office (whose very existence was a secret at the time) had begun to operate the KH-11 KENNEN digital imaging satellites in the 1970s. Unlike earlier spysats, which exposed film and returned it to the Earth for processing and interpretation, the KH-11 had a digital camera and the ability to transmit imagery to ground stations shortly after it was captured. There were few things so secret in 1981 as the existence and capabilities of the KH-11. Among the people briefed in on this above top secret program were the NASA astronauts who had previously been assigned to the Manned Orbiting Laboratory program which was, in fact, a manned reconnaissance satellite with capabilities comparable to the KH-11.

Dancing around classification, compartmentalisation, bureaucratic silos, need to know, and other barriers, people who understood what was at stake made it happen. The flight plan was rewritten so that Columbia was pointed in the right direction at the right time, the KH-11 was programmed for the extraordinarily difficult task of taking a photo of one satellite from another, when their closing velocities are kilometres per second, relaying the imagery to the ground and getting it to the NASA people who needed it without the months of security clearance that would normally entail. The shuttle was a key national security asset. It was to launch all reconnaissance satellites in the future. Reagan was in the White House. They made it happen. When the time came for Columbia to come home, the very few people who mattered in NASA knew that, however many other things they had to worry about, the tiles on the belly were not among them.

(How different it was in 2003 when the same Columbia suffered a strike on its left wing from foam shed from the external fuel tank. A thoroughly feckless and bureaucratised NASA rejected requests to ask for reconnaissance satellite imagery which, with two decades of technological improvement, would have almost certainly revealed the damage to the leading edge which doomed the orbiter and crew. Their reason: “We can't do anything about it anyway.” This is incorrect. For a fictional account of a rescue, based upon the report [PDF, scroll to page 173] of the Columbia Accident Investigation Board, see Launch on Need [February 2012].)

This is a masterful telling of a gripping story by one of the most accomplished of aerospace journalists. Rowan White is the author of Vulcan 607 (May 2010), the definitive account of the Royal Air Force raid on the airport in the Falkland Islands in 1982. Incorporating extensive interviews with people who were there, then, and sources which were classified until long after the completion of the mission, this is a detailed account of one of the most consequential and least appreciated missions in U.S. manned space history which reads like a techno-thriller.

Posted at 23:48 Permalink

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 14:19 Permalink