Fourmilog: None Dare Call It Reason

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Sunday, March 31, 2013

Reading List: Colossus

Copeland, B. Jack, ed. Colossus. Oxford: Oxford University Press, 2006. ISBN 978-0-19-953680-1.

During World War II the British codebreakers at Bletchley Park provided intelligence to senior political officials and military commanders which was vital in winning the Battle of the Atlantic and discerning German strategic intentions in the build-up to the invasion of France and the subsequent campaign in Europe. Breaking the German codes was just barely on the edge of possibility with the technology of the time, and required recruiting a cadre of exceptionally talented and often highly eccentric individuals and creating tools which laid the foundations for modern computer technology.

At the end of the war, all of the work of the codebreakers remained under the seal of secrecy: in Winston Churchill's history of the war it was never mentioned. Part of this was due to the inertia of the state to relinquish its control over information, but also because the Soviets, emerging as the new adversary, might adopt some of the same cryptographic techniques used by the Germans and concealing that they had been compromised might yield valuable information from intercepts of Soviet communications.

As early as the 1960s, publications in the United States began to describe the exploits of the codebreakers, and gave the mistaken impression that U.S. codebreakers were in the vanguard simply because they were the only ones allowed to talk about their wartime work. The heavy hand of the Official Secrets Act suppressed free discussion of the work at Bletchley Park until June 2000, when the key report, written in 1945, was allowed to be published.

Now it can be told. Fortunately, many of the participants in the work at Bletchley were young and still around when finally permitted to discuss their exploits. This volume is largely a collection of their recollections, many in great technical detail. You will finally understand precisely which vulnerabilities of the German cryptosystems permitted them to be broken (as is often the case, it was all-too-clever innovations by the designers intended to make the encryption “unbreakable” which provided the door into it for the codebreakers) and how sloppy key discipline among users facilitated decryption. For example, it was common to discover two or more messages encrypted with the same key. Since encryption was done by a binary exclusive or (XOR) of the bits of the Baudot teleprinter code, with that of the key (generated mechanically from a specified starting position of the code machine's wheels), if you have two messages encrypted with the same key, you can XOR them together, taking out the key and leaving you with the XOR of the plaintext of the two messages. This, of course, will be gibberish, but you can then take common words and phrases which occur in messages and “slide” them along the text, XORing as you go, to see if the result makes sense. If it does, you've recovered part of the other message, and by XORing with either message, that part of the key. This is something one could do in microseconds today with the simplest of computer programs, but in the day was done in kiloseconds by clerks looking up the XOR of Baudot codes in tables one by one (at least until they memorised them, which the better ones did).

The chapters are written by people with expertise in the topic discussed, many of whom were there. The people at Bletchley had to make up the terminology for the unprecedented things they were doing as they did it. Due to the veil of secrecy dropped over their work, many of their terms were orphaned. What we call “bits” they called “pulses”, “binary addition” XOR, and ones and zeroes of binary notation crosses and dots. It is all very quaint and delightful, and used in most of these documents.

After reading this book you will understand precisely how the German codes were broken, what Colossus did, how it was built and what challenges were overcome in constructing it, and how it was integrated into a system incorporating large numbers of intuitive humans able to deliver near-real-time intelligence to decision makers. The level of detail may be intimidating to some, but for the first time it's all there. I have never before read any description of the key flaw in the Lorenz cipher which Colossus exploited and how it processed messages punched on loops of paper tape to break into them and recover the key.

The aftermath of Bletchley was interesting. All of the participants were sworn to secrecy and all of their publications kept under high security. But the know-how they had developed in electronic computation was their own, and many of them went to Manchester to develop the pioneering digital computers developed there. The developers of much of this technology could not speak of whence it came, and until recent years the history of computing has been disconnected from its roots.

As a collection of essays, this book is uneven and occasionally repetitive. But it is authentic, and an essential document for anybody interested in how codebreaking was done in World War II and how electronic computation came to be.

Posted at 23:46

Friday, March 29, 2013

Reading List: A Time for War

Savage, Michael [Michael Alan Weiner]. A Time for War. New York: St. Martin's Press, 2013. ISBN 978-0-312-65162-6.

The author, a popular talk radio host who is also a Ph.D. in nutritional ethnomedicine and has published numerous books under his own name, is best known for his political works, four of which have made the New York Times bestseller list including one which reached the top of that list. This is his second foray into the fictional thriller genre, adopting a style reminiscent of Rudy Rucker's transrealism, in which the author, or a character closely modelled upon him or her, is the protagonist in the story. In this novel, Jack Hatfield is a San Francisco-based journalist dedicated to digging out the truth and getting it to the public by whatever means available, immersed in the quirky North Beach culture of San Francisco, and banned in Britain for daring to transgress the speech codes of that once-free nation. Sound familiar?

After saving his beloved San Francisco from an existential threat in the first novel, Abuse of Power (June 2012), Hatfield's profile on the national stage has become higher than ever, but that hasn't helped him get back into the media game, where his propensity for telling the truth without regard to political correctness or offending the perennially thin-skinned makes him radioactive to mainstream outlets. He manages to support himself as a free-lance investigative reporter, working from his boat in a Sausalito marina, producing and selling stories to venues willing to run them. When a Chinook helicopter goes down in a remote valley in Afghanistan killing all 39 on board and investigators attribute the crash to total failure of all electronics on board with no evidence of enemy action, Jack's ears perk up. When he later learns of an FBI vehicle performing a routine tail of a car from the Chinese consulate being disabled by “total electronic failure” he begins to get really interested. Then strange things begin to happen in Chinatown, prompting Jack to start looking for a China connection between these incidents.

Meanwhile, Dover Griffith, a junior analyst at the Office of Naval Intelligence, is making other connections. She recalled that a proposed wireless Internet broadband system developed by billionaire industrialist Richard Hawke's company had to be abandoned when it was discovered its signal could induce catastrophic electrical failure in aircraft electronics. (Clearly Savage is well-acquainted with the sorry history of LightSquared and GPS interference!) When she begins to follow the trail, she is hauled into her boss's office and informed she is being placed on “open-ended unpaid furlough”: civil service speak for being fired. Clearly Hawke has plenty of pull in high places and probably something to hide. Since Hatfield had been all over the story of interference caused by the broadband system and the political battle over whether to deploy it, she decides to fly to California and join forces with Hatfield to discover what is really going on. As they, along with Jack's associates, begin to peel away layer after layer of the enigma, they begin to suspect that something even more sinister may be underway.

This is a thoroughly satisfying thriller. There is a great deal of technical detail, all meticulously researched. There are a few dubious aspects of some of the gadgets, but that's pretty much a given in the thriller genre. What distinguishes these novels from other high-profile thrillers is that Jack Hatfield isn't a superhero in the sense of Vince Flynn's Mitch Rapp or Brad Thor's Scot Harvath: he is a largely washed-up journalist, divorced, living on a boat with a toy poodle, hanging out with a bunch of eccentric characters at an Italian restaurant in North Beach, who far from gunplay and derring-do, repairs watches for relaxation. This makes for a different kind of thriller, but one which is no less satisfying. I'm sure Jack Hatfield will be back, and I'm looking forward to the next outing.

You can read this novel as a stand-alone thriller without having first read Abuse of Power, but be warned that it contains major plot spoilers for the first novel; to fully enjoy them both, it's best to start there.

Posted at 18:04

Wednesday, March 27, 2013

Reading List: The Vatican Diaries

Thavis, John. The Vatican Diaries. New York: Viking, 2013. ISBN 978-0-670-02671-5.

Jerry Pournelle's Iron Law of Bureaucracy states that:

…in any bureaucratic organization there will be two kinds of people: those who work to further the actual goals of the organization, and those who work for the organization itself. Examples in education would be teachers who work and sacrifice to teach children, vs. union representatives who work to protect any teacher including the most incompetent. The Iron Law states that in all cases, the second type of person will always gain control of the organization, and will always write the rules under which the organization functions.

Imagine a bureaucracy in which the Iron Law has been working inexorably since the Roman Empire.

The author has covered the Vatican for the Catholic News Service for the last thirty years. He has travelled with popes and other Vatican officials to more than sixty countries and, developing his own sources within a Vatican which is simultaneously opaque to an almost medieval level in its public face, yet leaks like a sieve as factions try to enlist journalists in advancing their agendas. In this book he uses his access to provide a candid look inside the Vatican, at a time when the church is in transition and crisis.

He begins with a peek inside the mechanics of the conclave which chose Pope Benedict XVI: from how the black or white smoke is made to how the message indicating the selection of a new pontiff is communicated (or not) to the person responsible for ringing the bell to announce the event to the crowds thronging St Peter's Square.

There is a great deal of description, bordering on gonzo, of the reality of covering papal visits to various countries: in summary, much of what you read from reporters accredited to the Vatican comes from their watching events on television, just as you can do yourself.

The author does not shy from controversy. He digs deeply into the sexual abuse scandals and cover-up which rocked the church, the revelations about the founder of the Legion of Christ, the struggle between then traditionalists of the Society of St Pius X and supporters of the Vatican II reforms in Rome, and the battle over the beatification of Pope Pius XII. On the lighter side, we encounter the custodians of Latin, including the Vatican Bank ATM which displays its instructions in Latin: “Inserito scidulam quaeso ut faciundum cognoscas rationem”.

This is an enlightening look inside one of the most influential, yet least understood, institutions in what remains of Western civilisation. On the event of the announcement of the selection of Pope Francis, James Lileks wrote:

…if you'd turned the sound down on the set and shown the picture to Julius Cæsar, he would have smiled broadly. For the wrong reasons, of course—his order did not survive in its specific shape, but in another sense it did. The architecture, the crowds, the unveiling would have been unmistakable to someone from Cæsar's time. They would have known exactly what was going on.

Indeed—the Vatican gets ceremony. What is clear from this book is that it doesn't get public relations in an age where the dissemination of information cannot be controlled, and that words, once spoken, cannot be taken back, even if a “revised and updated” transcript of them is issued subsequently by the bureaucracy.

In the Kindle edition the index cites page numbers in the hardcover print edition which are completely useless since the Kindle edition does not contain real page numbers.

Posted at 22:56

Monday, March 18, 2013

Reading List: Rockets and People. Vol. 4

Chertok, Boris E. Rockets and People. Vol. 4. Washington: National Aeronautics and Space Administration, [1999] 2011. ISBN 978-1-4700-1437-7 NASA SP-2011-4110.

This is the fourth and final book of the author's autobiographical history of the Soviet missile and space program. Boris Chertok was a survivor, living through the Bolshevik revolution, the Russian civil war, Stalin's purges of the 1930s, World War II, all of the postwar conflict between chief designers and their bureaux and rival politicians, and the collapse of the Soviet Union. Born in Poland in 1912, he died in 2011 in Moscow. As he says in this volume, “I was born in the Russian Empire, grew up in Soviet Russia, achieved a great deal in the Soviet Union, and continue to work in Russia.” After retiring from the RKK Energia organisation in 1992 at the age of 80, he wrote this work between 1994 and 1999. Originally published in Russian in 1999, this annotated English translation was prepared by the NASA History Office under the direction of Asif A. Siddiqi, author of Challenge to Apollo (April 2008), the definitive Western history of the Soviet space program.

This work covers the Soviet manned lunar program and the development of long-duration space stations and orbital rendezvous, docking, and assembly. As always, Chertok was there, and participated in design and testing, was present for launches and in the control centre during flights, and all too often participated in accident investigations.

In retrospect, the Soviet manned lunar program seems almost bizarre. It did not begin in earnest until two years after NASA's Apollo program was underway, and while the Gemini and Apollo programs were a step-by-step process of developing and proving the technologies and operational experience for lunar missions, the Soviet program was a chaotic bag of elements seemingly driven more by the rivalries of the various chief designers than a coherent plan for getting to the Moon. First of all, there were two manned lunar programs, each using entirely different hardware and mission profiles. The Zond program used a modified Soyuz spacecraft launched on a Proton booster, intended to send two cosmonauts on a circumlunar mission. They would simply loop around the Moon and return to Earth without going into orbit. A total of eight of these missions were launched unmanned, and only one completed a flight which would have been safe for cosmonauts on board. After Apollo 8 accomplished a much more ambitious lunar orbital mission in December 1968, a Zond flight would simply demonstrate how far behind the Soviets were, and the program was cancelled in 1970.

The N1-L3 manned lunar landing program was even more curious. In the Apollo program, the choice of mission mode and determination of mass required for the lunar craft came first, and the specifications of the booster rocket followed from that. Work on Korolev's N1 heavy lifter did not get underway until 1965—four years after the Saturn V, and it was envisioned as a general purpose booster for a variety of military and civil space missions. Korolev wanted to use very high thrust kerosene engines on the first stage and hydrogen engines on the upper stages as did the Saturn V, but he was involved in a feud with Valentin Glushko, who championed the use of hypergolic, high boiling point, toxic propellants and refused to work on the engines Korolev requested. Hydrogen propellant technology in the Soviet Union was in its infancy at the time, and Korolev realised that waiting for it to mature would add years to the schedule.

In need of engines, Korolev approached Nikolai Kuznetsov, a celebrated designer of jet turbine engines, but who had no previous experience at all with rocket engines. Kuznetsov's engines were much smaller than Korolev desired, and to obtain the required thrust, required thirty engines on the first stage alone, each with its own turbomachinery and plumbing. Instead of gimballing the engines to change the thrust vector, pairs of engines on opposite sides of the stage were throttled up and down. The gargantuan scale of the lower stages of the N-1 meant they were too large to transport on the Soviet rail network, so fabrication of the rocket was done in a huge assembly hall adjacent to the launch site. A small city had to be built to accommodate the work force.

All Soviet rockets since the R-2 in 1949 had used “integral tanks”: the walls of the propellant tanks were load-bearing and formed the skin of the rocket. The scale of the N1 was such that load-bearing tanks would have required a wall thickness which exceeded the capability of Soviet welding technology at the time, forcing a design with an external load-bearing shell and separate propellant tanks within it. This increased the complexity of the rocket and added dead weight to the design. (NASA's contractors had great difficulty welding the integral tanks of the Saturn V, but NASA simply kept throwing money at the problem until they figured out how to do it.)

The result was a rocket which was simultaneously huge, crude, and bewilderingly complicated. There was neither money in the budget nor time in the schedule to build a test stand to permit ground firings of the first stage. The first time those thirty engines fired up would be on the launch pad. Further, Kuznetsov's engines were not reusable. After every firing, they had to be torn down and overhauled, and hence were essentially a new and untested engine every time they fired. The Saturn V engines, by contrast, while expended in each flight, could be and were individually test fired, then ground tested together installed on the flight stage before being stacked into a launch vehicle.

The weight and less efficient fuel of the N-1 made its performance anæmic. While it had almost 50% more thrust at liftoff than the Saturn V, its payload to low Earth orbit was 25% less. This meant that performing a manned lunar landing mission in a single launch was just barely possible. The architecture would have launched two cosmonauts in a lunar orbital ship. After entering orbit around the Moon, one would spacewalk to the separate lunar landing craft (an internal docking tunnel as used in Apollo would have been too heavy) and descend to the Moon. Fuel constraints meant the cosmonaut only had ten to fifteen seconds to choose a landing spot. After the footprints, flag, and grabbing a few rocks, it was back to the lander to take off to rejoin the orbiter. Then it took another spacewalk to get back inside. Everybody involved at the time was acutely aware how marginal and risky this was, but given that the N-1 design was already frozen and changing it or re-architecting the mission to two or three launches would push out the landing date four or five years, it was the only option that would not forfeit the Moon race to the Americans.

They didn't even get close. In each of its test flights, the N-1 did not even get to the point of second stage ignition (although in its last flight it got within seven seconds of that milestone). On the second test flight the engines cut off shortly after liftoff and the vehicle fell back onto the launch pad, completely obliterating it in the largest artificial non-nuclear explosion known to this date: the equivalent of 7 kilotons of TNT. After four consecutive launch failures, having lost the Moon race, with no other mission requiring its capabilities, and the military opposing an expensive program for which they had no use, work on the N-1 was suspended in 1974 and the program officially cancelled in 1976.

When I read Challenge to Apollo, what struck me was the irony that the Apollo program was the very model of a centrally-planned state-directed effort along Soviet lines, while the Soviet Moon program was full of the kind of squabbling, turf wars, and duplicative competitive efforts which Marxists decry as flaws of the free market. What astounded me in reading this book is that the Soviets were acutely aware of this in 1968. In chapter 9, Chertok recounts a Central Committee meeting in which Minister of Defence Dmitriy Ustinov remarked:

…the Americans have borrowed our basic method of operation—plan-based management and networked schedules. They have passed us in management and planning methods—they announce a launch preparation schedule in advance and strictly adhere to it. In essence, they have put into effect the principle of democratic centralism—free discussion followed by the strictest discipline during implementation.

In addition to the Moon program, there is extensive coverage of the development of automated rendezvous and docking and the long duration orbital station programs (Almaz, Salyut, and Mir). There is also an enlightening discussion, building on Chertok's career focus on control systems, of the challenges in integrating humans and automated systems into the decision loop and coping with off-nominal situations in real time.

I could go on and on, but there is so much to learn from this narrative, I'll just urge you to read it. Even if you are not particularly interested in space, there is much experience and wisdom to be gained from it which are applicable to all kinds of large complex systems, as well as insight into how things were done in the Soviet Union. It's best to read Volume 1 (May 2012), Volume 2 (August 2012), and Volume 3 (December 2012) first, as they will introduce you to the cast of characters and the events which set the stage for those chronicled here.

As with all NASA publications, the work is in the public domain, and an online edition in PDF, EPUB, and MOBI formats is available.

A commercial Kindle edition is available which is much better produced than the Kindle editions of the first three volumes. If you have a suitable application on your reading device for one of the electronic book formats provided by NASA, I'd opt for it. They're free.

The original Russian edition is available online.

Posted at 23:35

Saturday, March 9, 2013

Levitating pyrolytic carbon

It's been a while since the last gizmo post. Here's one of the coolest things I've encountered in some time, and what's especially remarkable about it is how warm it is—it works at room temperature.

Many visitors to this site are probably sufficiently nerdly to have, at some point in their lives, levitated a magnet above a piece of high-temperature superconductor, demonstrating the Meissner effect to the amazement of all onlookers. Unfortunately, “high-temperature” in this context means only that it works at the temperature of liquid nitrogen, not liquid helium, so you still have to go off to the welding supply shop with a thermos, and the experiment only works until you run out of liquid nitrogen.

Amazingly, you can do a similar demonstration of levitation at room temperature by using a diamagnetic substance and a strong permanent magnet. A diamagnetic material has a magnetic permeability less than that of free space, and hence expels external magnetic fields, creating a repulsive field in response. This is usually a weak effect.

Pyrolytic carbon exhibits the strongest diamagnetic effect at room temperature of any known substance. It is a form of carbon not found in nature, but which can be produced by a variety of processes. Its structure is similar to that of graphite, except there are covalent bonds between atoms in the graphene sheets of which it is composed.

To the right is a small square piece of pyrolytic carbon. To the left are four neodymium-iron-boron magnets stuck to a steel plate at the bottom. What happens when we pick up the carbon square and place it atop the magnets?

Whoa! Its diamagnetism causes it to levitate above the magnets. If you perturb it from its minimum-energy state, it will return to the centre point and the same orientation. If you tilt the magnets slightly, the carbon square will shift to balance the force of gravity. (If you tilt it beyond the diamagnetic restoring force, the carbon square will fall off onto the table.). The following picture gives a sense of scale.

If you want to try this yourself at home, you can usually find everything you need on eBay. For some reason, you'll need to search for “pyrolytic graphite”; eBay has its own vernacular for such things. Neodymium magnets are extraordinarily strong, and you should always be cautious when dealing with them. Make sure you have anything magnetic far away, and never, ever allow your finger to get between one of these magnets and something magnetic. If you want to experiment with displacing or spinning the levitated carbon square, a wooden toothpick is an excellent implement; a screwdriver, not so much. Also be careful how you store the magnets. They can wipe the magnetic stripes on credit cards brought near them and erase other kinds of magnetic media. I doubt they'd cause any problem with a hard drive within a computer, but darned if I'm going to let them anywhere near one of my computers. I took all of these photos on a wooden table after making sure there was nothing magnetic within two metres.

And if you have a really strong magnet, note that frogs are diamagnetic.

Posted at 21:36