Archive for the ‘Uncategorized’ Category

From the Chronicles of Scruffy Versus Neat: the Lighthill Affair

February 18, 2011

The 1973 Lighthill Affair was an Affair in the sense of the Dreyfus and Profumo Affairs. And although it was scaled down to teacup size, it was big enough to make it into a textbook published twenty years later:

… the Lighthill Report, which formed the basis for the decision by the British government to end support of AI research in all but two universities. (Oral tradition paints a somewhat different and more colorful picture, with political ambitions and personal animosities that cannot be put into print.) [1]

In this article I will put in print some of the things hinted at here, and elaborate on the issues that have remained topical.


Who Killed Prolog?

August 21, 2010

There are a thousand programming languages out there (Literally, it seems, according to people who actually count such things.) A classification of so many species is bound to be complex and subject to much debate. However messy and controversial things get low down in the classification, let’s have just four branches at the top level. I attach to the name of the class of programming language what I consider to be the first exemplar of the class, in chronological order:

— imperative (1956, Fortran)
— functional (1959, Lisp)
— object-oriented (1972, Smalltalk)
— logic (1974, Prolog)

I take as starting point the fact that three of the four branches are doing well in the sense of having a vigorous following. Compared to these three, Prolog has fallen far behind. This was not the case in the early 1980’s, when Prolog had caught up with Lisp in capturing mindshare of what you could call non-IBM computing (to avoid the vexed term “AI”). Hence the title of this article. As culprit (or benefactor, depending on how you look at it) I identify the Japanese “Fifth-Generation Computer System” project, which existed from 1982 to 1992.


I remember Donald Michie (1923 – 2007)

June 12, 2009

On July 7, 2007 Dame Anne McLaren and Donald Michie died in a car accident. Last time I had met Anne was in the 1970s when I stayed at their house in Edinburgh. Both were launched on scientific careers that were to lead them to positions rivalling each others’ eminence in their respective fields.

The last time I met Donald (henceforth “DM”) was when my wife and I visited him in Oxford in November 2004. He demo’ed the Sophie chatbot system, asking us what we thought of his choice of accent for the speech-generating software. He was intrigued by the way his current choice, labeled “Southern California Trash”, blended with the other personality attributes of Sophie. The stereo was playing DM’s current favourite, “Harper Valley PTA” sung by Jeannie C. Riley, another sassy American female.

Although excited by his current project, DM was depressed by the gloomy British weather; he would depart shortly to spend the winter in Gibraltar. “Gibraltar??”. “Yes, Gibraltar. I trust it will be sunny, and it is British.” In the following pages I have noted, roughly in chronological order, some experiences with this extraordinary man, one of the great pioneers in Artificial Intelligence.


Digital Gold

May 31, 2008

The true nature of money has, through the centuries, been an inexhaustible source of puzzlement. This has abated somewhat in the Greenspan era when currency management sort of limped along by being conducted according to business as usual. Post Greenspan, the avalanche of crises triggered by the subprime debacle should have come as a wake-up call that business as usual is a recipe for disaster. But you wouldn’t guess so from The Economist’s Special Report on International Banking (May 17, 2008), which foresees return to “normal” after a “salutary dose of reality”. This underlines what many readers have noticed, namely that The Economist is not what its title suggests, but rather is The Voice of the Industry.

One of the ways in which The Economist affirms its orthodoxy is to state or suggest that only cranks entertain ideas like the gold standard or social credit. The Web is more rewarding in this respect. For example, the Wikipedia article (version of 080530) on the gold standard tells that Alan Greenspan, this pillar of orthodoxy, was once a proponent of its return.

Though the gold standard is a lousy system, it has the advantage of being a fruitful starting point in the search for something better. Business as usual does not have this property. The problem with the gold standard is that the money supply is rigidly equated to the amount of gold that circulates as coins or serves as back-up to paper certificates. In the 16th century, when the gold of the New World was imported into Europe, this gave rise to a large amount of inflation. In the 1930s the US economy required a larger supply of money than was available under the then reigning gold standard, thus aggravating the depression.

These problems suggested a monetary system in which economists determine the money supply needed by the state of the economy and in which governments have various means at their disposal to ensure that the actual money supply closely approximates this ideal. Both economists and governments like this idea: they are flattered by the power it ascribes to them.

This may have worked for a while, but since asset-backed securities, credit derivatives, and hedge funds neither governments, nor anybody else, has any idea what the money supply is. So there we are: equating the money supply to a gold reserve at a fixed price doesn’t work. Alternative ways of controlling the money supply, such as the M1 and M2 of yore don’t work. Isn’t there anything else?

There is a lot one can do nowadays with digital authentication techniques. It is time to investigate whether it is possible to implement digitally a collection of monetary certificates that is the equivalent of the Federal Reserve’s gold supply in the days of the gold standard. These digital techniques have been used for message authentication and digital signatures. It is worth investigating whether they can be used to create a digital one million dollar version of the hundred-dollar bill signed by the Secretary of the Treasury.