Friday, May 2, 2008

Boot story

Computer users are familiar with the verb boot, meaning to restart the machine. The full term is bootstrap, which is a noun designating the small leather loops at the back of boots, enabling you to pull them on.

There's an old metaphorical expression in English, "pull oneself up by one's own bootstraps", which means to take care of oneself, or get oneself out of dire straits, without the help of anybody else. It is said that the absurd image of pulling on your bootstraps in order to raise your whole body (into the air, say) was used for the first time in the apocryphal tales of Baron Munchausen, who apparently employed this technique to save himself from drowning in a swamp. I haven't been able to find any precise extract in the 1895 edition of the novel in English by Rudolph Erich Raspe, so I imagine that the anecdote appeared in one of the numerous literary remakes of the alleged adventures of Munchausen.

Meanwhile, I take this opportunity of pointing out that a new and complete edition of Terry Gilliam's fabulous film will be coming out shortly on DVD [I'm awaiting my copy from Amazon] to mark the 20th anniversary of its production.

Talking about boots, my room-mate at the La Parisière clinic in February used to operate his own shoe-manufacturing business in Romans, and he gave me the address of one of the only surviving small firms in this domain, started by an Armenian family in 1945.

Their tiny boutique is located on the river front, a few hundred meters up from the great church called the collégiale Saint-Barnard, where the Dauphiné province was handed over officially to the king of France in 1349. My friend had warned me that the range of shoes made by Tchilinguirian is narrow. But, if you come across a suitable model and size, you're able to purchase a product whose quality is likely to be far superior to what you find in ordinary shoes shops. I was lucky, for I found an ideal pair of boots:

Let's get back to the bootstrap metaphor, as used in computing. To understand what it's all about, we should think of a system that exists in one of two states. At the beginning, it's turned off, like an unlit lamp. Later, it's turned on, and ready to perform tasks. The general idea is that the system moves itself, as it were, from a state of total inactivity, to an operational state. And that transition is what we refer to as a bootstrap process.

Somebody suggested an easy-to-understand illustration of the bootstrap concept in the context of bridge construction. Imagine a ravine in the jungle, over which we would like to build a sturdy footbridge. How can we use a bootstrap approach to take us from the no-bridge state to the sturdy-footbridge state? The demonstration works most effectively if we imagine two men, on opposite edges of the ravine. One of them uses a bow and arrow to shoot the free end of a piece of string across the ravine. Once the string is secured, a lightweight pulley is attached to it in such a way as to make it possible to drag a rope across the the ravine. Then the rope is used in a similar fashion to drag a steel cable across the ravine. And so on, using increasingly heavier and stronger cables, up until there's a full-fledged footbridge across the ravine.

These days, one has the impression that a computer is turned on just like a light switch, so the notion of the machine "pulling itself up by its own bootstraps" doesn't really come across explicitly, let alone vividly. In the early days of commercial computing [in the late '50s and early '60s, when I worked as a programer with IBM in Sydney], we were truly obliged to understand the bootstrap concept, because the computer's memory would be totally empty, and we had to invent techniques for coaxing the machine to "swallow" fragments of code up until there was a complete executable program in its memory. In those days, the piece of string to be shot across the ravine took the form of a primordial instruction that we would spell out using switches on the machine's console. That instruction would ask the computer to read in, say, a punched card, containing further instructions, and so on. We could even sympathize with the poor machine straining to acquire a sufficiently rich stack of code to make itself useful.

Today, the bootstrap metaphor is often used in an unexpected context, of a far more profound nature than footbridges across ravines or programs in the memory of computers. The fundamental philosophical question posed by LeibnizWhy is there being rather than nothingness?—is essentially a bootstrap enigma. In the beginning, long before Darwinian evolution got into swing, what kind of a bootstrap process might have occurred to make possible the transition from apparent nothingness into somethingness? One thing is certain. In accordance with the bootstrap concept, this transition must have started in an amazingly simple fashion... because there isn't room for much complexity in the state we refer to as nothingness! So, this process couldn't possibly have been inaugurated by an infinitely complex entity of the "God" kind. That last sentence doesn't say much, and yet, for an atheist such as me, it says everything. In the beginning, "God" was certainly absent.

No comments:

Post a Comment