Footnote --On the Perils of Positive Feedback....
When things shrug off the bonds of control and start to get weird, positive feedback is usually in the driver's seat. The very word ``feedback'' means, to many people, one of the most common examples of positive feedback: the deafening scream when a microphone picks up a sound from a speaker and sends it back to the speaker which emits it even louder, which is picked up by the microphone....
Positive feedback makes for humorous anecdotes. But the real world contains, sadly, many examples of positive feedback put in place by well-meaning politicians and businessmen who don't understand the consequences of crossing the wires between noble ends and expedient means. Consider the nuclear arms race. At the end of World War II, the United States and Britain realised they couldn't afford to match the Soviet army in Europe so they built nuclear bombs and threatened all-out destruction of the Soviet homeland in response to any aggression. The Soviets, faced with the ultimate threat, accelerated their own nuclear program in the belief that only by matching or surpassing the West could they deal on an equal basis. Once the Soviets tested their bomb, hysteria in the West was compounded--now they faced an adversary armed with the Bomb as well as a huge army. The only way to deter the Soviets from using their bomb was to build mo' bigger bombs. And so on, as fear fed on fear, technological developments like the ballistic missile spurred further developments and countermeasures by the other side, the
whole process consumed a substantial fraction of all the world's wealth for decades. This tragedy of our age is, at its heart, a case of positive feedback, pure and simple. And like most examples of positive feedback it was stopped (if indeed it has ceased and not just gone on vacation), not by good will, not through mutual understanding and trust, not by the actions of diplomats and politicians, but by the application of stronger negative feedback. The negative feedback in the arms race was economic: the race grew to the point where it virtually bankrupted the participants who were, only then, compelled to slow down.
Once you begin to analyse things in terms of positive and negative feedback, you'll never see things quite the same.
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