Archive for March, 2010

Vale: Robin Milner

The death has just occurred of Robin Milner (1934-2010), one of the founders of theoretical computer science.   Milner was an ACM Turing Award winner and his main contributions were a formal theory of concurrent communicating processes and, more recently, a category-theoretic account of hyperlinks and embeddings, his so-called theory of bigraphs.   As we move into an era where the dominant metaphor for computation is computing-as-interaction, the idea of concurrency has become increasingly important; however, understanding, modeling and managing it have proven to be among the most difficult conceptual problems in modern computer science.  Alan Turing gave the world a simple mathematical model of computation as the sequential writing or erasing of characters on a linear tape under a read/write head, like a single strip of movie film passing back and forth through a projector.  Despite the prevalence of the Internet and of ambient, ever-on, and ubiquitous computing, we still await a similar mathematical model of interaction and interacting processes.  Milner’s work is a major contribution to developing such a model. In his bigraphs model, for example, one graph represents the links between entities while the other represents geographic proximity or organizational hierarchy.

Robin was an incredibly warm, generous and unprepossessing man.   About seven years ago, without knowing him at all, I wrote to him inviting him to give an academic seminar; even though famous and retired, he responded positively, and was soon giving a very entertaining talk on bigraphs (a representation of which is on the blackboard behind him in the photo).  He joined us for drinks in the pub afterwards, buying his round like everyone else, and chatting amicably with all, talking both about the war in Iraq and the problems of mathematical models based on pre-categories.  He always responded immediately to any of my occasional emails subsequently.

The London Times has an obituary here, and the Guardian here (from which the photo is borrowed).


Robin Milner [1989]: Communication and Concurrency. Prentice Hall.

Robin Milner [1999]: Communicating and Mobile Systems: the Pi-Calculus. Cambridge University Press.

Robin Milner [2009]: The Space and Motion of Communicating Agents. Cambridge University Press.

Operational incompetence at CIA

At the end of December 2009, an Al Qaeda double agent killed himself and seven CIA agents and security staff at a US base in Khost,  Afghanistan.   Former CIA agent and writer, Robert Baer, has an account of the tragedy in a fascinating article in next month’s GQ, here.   Baer argues, as he has before, that CIA management have systematically and deliberately destroyed the agency’s capabilities for human espionage – that field operations are devalued, that field operational skills are not taught, not learnt, and not acquired, that junior field staff are not mentored, and that field skills and experience are not rewarded within the agency.   Organizational lack of attention to operational skills allowed a junior and field-inexperienced analyst to be appointed head of the Khost base, allowed that analyst to be appointed with neither knowledge of the local language nor prior local experience, allowed her to arrange a meeting with a human informant at the base (instead of off-base), allowed her to arrange a meeting with a human informant that no one locally had previously met, allowed numerous other people to attend this meeting, allowed this meeting to be discussed ahead of time back at Langley and in the White House, and allowed the informant to pass through three security checkpoints without being checked for weapons or bombs.  They even baked a birthday cake for their visiting suicide bomber.  The numbers killed made this the worst disaster for CIA since the 1983 bombing of the US Embassy in Beirut.

Retrospect, of course, is always wiser than prospect.  But one has to wonder how low the level of espionage tradecraft could be that so many gross errors were made.  Baer puts the blame squarely on the deprofessionalization of CIA’s field operations, especially since John Deutch’s time as Director (1995-1996).

At the end of his article, Baer says:

The United States still needs a civilian intelligence agency. (The military cannot be trusted to oversee all intelligence-gathering on its own.)”

In his memoirs, former US Defense Secretary Robert McNamara said that one lesson he’d learnt from the US military involvement in Vietnam was the need for an independent and objective source of intelligence on progress (eg, numbers and locations of enemy engagements; the outcomes of engagements; assessments of enemy strength and morale; etc).  In Vietnam, this information was not provided to the White House by CIA or any other independent agency, but by the US military themselves, and was therefore subject to distortion, to bias, and to outright manipulation.  The people firing the arrows were the same people drawing the targets for the arrows and counting how many bullseyes the archers had achieved.

A recent CNN interview with Robert Baer is here (conducted 2010-03-16).

A previous post which mentions Robert Baer is here.

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Metrosexual competition

Writing about the macho world of pure mathematics (at least, in my experience, in analysis and group theory, less so in category theory and number theory, for example), led me to think that some academic disciplines seem hyper-competitive:  physics, philosophy and mainstream economics come to mind.  A problem for economics is that the domain of the discipline includes the study of competition, and the macho, hyper-competitive nature of academic economists has led them, I believe, astray in their thinking about the marketplace competition they claim to be studying.  They have assumed that their own nasty, bullying, dog-eat-dog world is a good model for the world of business.

If business were truly the self-interested, take-no-prisoners world of competition described in economics textbooks and assumed in mainstream economics, our lives would all be very different.  Fortunately, our world is mostly not like this.   One example is in telecommunications where companies compete and collaborate with each other at the same time, and often through the same business units.  For instance, British Telecommunications and Vodafone are competitors (both directly in the same product categories and indirectly through partial substitutes such as fixed and mobile services), and collaborators, through the legally-required and commercially-sensible inter-connections of their respective networks.  Indeed, for many years, each company was the other company’s largest customer, since the inter-connection of their networks means each company completes calls that originate on the other’s network; thus each company receives payments from the other.  Do you seek to drive your main competitor out of business when that competitor is also your largest customer?   Would you do this, as stupid as it seems, knowing that your competitor could retaliate (perhaps pre-emptively!) by disconnecting your network or reducing the quality of your calls that interconnect?  No rational business manager would do this, although perhaps an economist might. 

Nor would you destroy your competitors when you and they are sharing physical infrastructure  – co-locating switches in each other’s buildings, for example, or sharing rural cellular base stations, both of which are common in telecommunications.   And, to complicate matters, large corporate customers of telecommunications companies increasingly want direct access to the telco’s own switches, leading to very porous boundaries between companies and their suppliers.   Doctrines of nuclear warfare, such as mutually-assured destruction or iterated prisoners’ dilemma, are better models for this marketplace than the mainstream one-shot utility-maximizing models, in my opinion.

You might protest that telecommunications is a special case, since the product is a networked good – that is, one where a customer’s utility from a particular service may depend on the numbers of other customers also using the service.    However, even for non-networked goods, the fact that business usually involves repeated interactions with the same group of people (and is decidely not a one-shot interaction) leads to more co-operation than is found in an economist’s philosophy.   The empirical studies of hedge funds undertaken by sociologist Donald MacKenzie, for example, showed the great extent to which hedge fund managers rely in their investment decisions on information they receive from their competitors.  Because everyone hopes to come to work tomorrow and the day after, as well as today, there are strong incentives on people not to  mis-use these networks through, for instance, disseminating false or explicitly-self-serving information.  

It’s a dog-help-dog world out there!


Iain Hardie and Donald MacKenzie [2007]:  Assembling an economic actor: the agencement of a hedge fund. The Sociological Review, 55 (1): 57-80.

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Mr Sculthorpe, please call your office

I was thinking recently about concert performances I have attended where the composer was present, or rather, where I knew the composer to be present.  Here is my list, as best I remember it:

Don Banks (1923-1980)
Richard Rodney Bennett (1936-2012)
Pierre Boulez (1925-2016)
Ann Carr-Boyd (Britannia Fanfare, 2012)
Barry Conyngham
Palle Dahlstedt
David Fanshawe (1942-2010, African Sanctus, Liverpool)
Rolf Hind
Robin Holloway
Keith Humble (1927-1995)
Gerard McBurney
Olivier Messiaen (1908-1992)
Stephen Montague (Piano Concerto)
Nico Muhly (premiere of Electric Violin Concerto, performed by Thomas Gould, and premiere of opera, Two Boys, at ENO)
Olli Mustonen (playing his own Sonata for Violin and Piano with Pekka Kuusisto, London 2013)
Tristan Murail (Reflections/Reflets, performed by the BBSO under Sakari Oramo, London 2013)
Loretta Notareschi
Jim Penberthy (1917-1999)
Behzad Ranjbaran (premiere of Violin Concerto, performed by Joshua Bell)
Peter Sculthorpe (1929-2014)
Larry Sitsky
Toru Takemitsu (1930-1996)
David Urquhart-Jones
James Wishart
Iannis Xenakis (1922-2001)

Of course, my presence at a performance does not constitute an endorsement of the music performed:  some of the music of these composers I like or appreciate very much, and some I think is unpleasant, boring or otherwise of low quality.   Although I generally prefer downtown and minimalist music, the music of the composers listed here also includes neo-romanticism (eg, Holloway, late Sculthorpe), abstract expressionism (eg, Penberthy, early Sculthorpe, Takemitsu), and uptown complexity (eg, Boulez, Muhly, Xenakis).  And, I have not included in this list jazz performers, who almost always play some of their own compositions.

For Peter Sculthorpe, one occasion (of several where we have both been present) was a performance in January 1975 near Patonga, Broken Bay, Sydney, of his profound and achingly-beautiful Sun Music III, in which I had the great good fortune, as second percussionist, to play the guiro (pictured).    One has to wonder how the same person could compose the innovative Sun Music series of the 1960s and also the derivative, warmed-over, late-romantic tosh that Sculthorpe has written in recent years.  Bill Burroughs would have seen it as a clear case of spirit possession.

POSTSCRIPT (2014-01-11):  New Zealander Alannah Currie, of The Thompson Twins, plays a guiro in their hit Hold Me Now (1983).  See video here.

Macho mathematicians

Pianist and writer Susan Tomes has just published a new book, Out of Silence, which the Guardian has excerpted here.  This story drew my attention:

Afterwards, my husband and I reminisced about our attempts to learn tennis when we were young. I told him that my sisters and I used to go down to the public tennis courts in Portobello. We had probably never seen a professional tennis match; we just knew that tennis was about hitting the ball to and fro across the net. We had a few lessons and became quite good at leisurely rallies, hitting the ball back and forth without any attempt at speed. Sometimes we could keep our rallies going for quite a long time, and I found this enjoyable.

Then our tennis teacher explained that we should now learn to play “properly”. It was only then that I realised we were meant to hit the ball in such a way that the other person could not hit it back. This came as an unpleasant surprise. As soon as we started “playing properly”, our points became extremely short. One person served, the other could not hit it back, and that was the end of the point. It seemed to me that there was skill in hitting the ball so that the other person could hit it back. If they could, the ball would flow, one got to move about and there was not much interruption to the rhythm of play. It struck me that hitting the ball deliberately out of the other person’s reach was unsportsmanlike. When I tell my husband all this, he laughs and says: “There speaks a true chamber musician.”

This story resonated strongly with me.  Earlier this year, I had a brief correspondence with mathematician Alexandre Borovik, who has been collecting accounts of childhood experiences of learning mathematics, both from mathematicians and from non-mathematicians.  After seeing a discussion on his blog about the roles of puzzles and games in teaching mathematics to children, I had written to him:

Part of my anger & frustration at school was that so much of this subject that I loved, mathematics, was wasted on what I thought was frivolous or immoral applications:   frivolous because of all those unrealistic puzzles, and immoral because of the emphasis on competition (Olympiads, chess, card games, gambling, etc).   I had (and retain) a profound dislike of competition, and I don’t see why one always had to demonstrate one’s abilities by beating other people, rather than by collaborating with them.  I believed that “playing music together”, rather than “playing sport against one another”, was a better metaphor for what I wanted to do in life, and as a mathematician.

Indeed, the macho competitiveness of much of pure mathematics struck me very strongly when I was an undergraduate student:  I switched then to mathematical statistics because the teachers and students in that discipline were much less competitive towards one another.  For a long time, I thought I was alone in this view, but I have since heard the same story from other people, including some prominent mathematicians.  I know one famous category theorist who switched from analysis as a graduate student because the people there were too competitive, while the category theory people were more co-operative.

Perhaps the emphasis on puzzles & tricks is fine for some mathematicians – eg, Paul Erdos seems to have been motivated by puzzles and eager to solve particular problems.  However, it is not fine for others – Alexander Grothendieck comes to mind as someone interested in abstract frameworks rather than puzzle-solving.  Perhaps the research discipline of pure mathematics needs people of both types.  If so, this is even more reason not to eliminate all the top-down thinkers by teaching only using puzzles at school.”

More on the two cultures of mathematics here.

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The sources of silence

I listed here many of the teachers and thinkers whose influence I have felt.   In his wonderful new book on John Cage’s 4′ 33”, the indefatigable Kyle Gann says this (pages 71-72):

The meme that Cage was more of a music philosopher than a composer has become commonplace, most of all, it seems, among people who don’t like his music and are in need of a way to justify his celebrity.  Cage was not a philosopher in any sense that the philosophy profession would recognize, but he was very much a composer who drew inspiration for his music from philosophical ideas.  The list of artists, writers, and thinkers he names in justification of his musical trajectory is a long one:  Meister Eckhart, Huang-Po, Kwang-Tse, Erik Satie, Henry David Thoreau, Gertrude Stein, Arnold Schoenberg, John Cage Sr., Marcel Duchamp, Sri Ramakrishna, Daisetz Sukuki, Joseph Campbell, Ananda K. Coomaraswamy, Alan Watts, Antonin Artaud, Robert Rauschenberg, Morton Feldman, David Tudor, Norman O. Brown, Marshall McLuhan, Buckminster Fuller, Gita Sarabhai, and Christian Wolff, among others.”

I was reminded of James Pritchett’s intention, when writing his book on Cage’s music, to as much as possible read everything that John Cage had himself read, and in the order he had done so.


Kyle Gann [2010]: No Such Thing as Silence.  John Cage’s 4′ 33”.  New Haven, CT, USA:  Yale University Press.

James Pritchett [1993]:  The Music of John Cage.  Cambridge, UK:  Cambridge University Press.