Tuesday, February 07, 2006

qubits

As I'm wandering around on Edge and thinking about the sagging old maid with the tumor, I'm beginning to think I ought to learn something about quantum computation. (Have a look at www.qubit.org for definitions and info on quantum computing.) What interests me is that it can be used in simulating quantum-mechanical systems. Maybe that means there will be less uncertainty about how we work. Or maybe it won't be relevant for anything as big as a person.

The University of Utah runs a yearly symposium on science and literature that may interest readers here. They describe their project so:

The foundational idea behind the symposium is that there is an important reciprocal influence between the sciences, the arts, and the humanities, though the ways in which current ideas are expressed and manifested, especially in our age of specialization, may be so different that the connections between them—as well as the ability to trace precedence—may not always be clear. Historically, for example, it is almost impossible for anyone who has even a basic understanding of Einstein to read much of Virginia Woolf's work without considering the impact of his ideas on her thinking, while chaos theory may have been predicted in the works of various 19th century writer.

I'm thinking it's time for the old maid to get a name. Let's call her...Roberta Rae. But I think everyone calls her Bobbie.

3 comments:

Digory said...

A couple of thoughts, which I am not sure where to put, so here they go -

At one point you were asking about whether accidents are really accidental or whether if we knew enough we could predict them. A growing area of awareness is that many phenomena are chaotic, which when used technically doesn't mean without any order. Rather it means that a small perturbation in initial conditions can lead to increasingly large divergences later on.

An example: people used to think that the solar system was like a great big watch, and that you could run it in reverse (in theory) for as far back as you liked. Now it is appreciated that the solar system is chaotic on a very long time scale. You can retrodict for quite a long way back, but eventually the resolution of the initial conditions is not enough to specify the pattern at that earlier time - a minute difference in the beginning conditions would mean an enormous difference after the relevant interval.

What this means is that there are some true accidents, events that could not in principle be predicted, no matter how good the information about the initial conditions was. How that shapes the human experience depends on how you handle accident.

In my family the metaphors of "the hand you're dealt" and "Saturday night soup" were used a fair bit. All of us were bridge players (some more enthusiatic than others) so saying that such-and-such an experience - one that seemed accidental - was just the hand you were dealt meant the interest lay in how you played it. Could you finesse the troublesome cards of your opponents? Could you communicate your hand's strengths and weaknesses to your partner? Was this the hand to play as fast as possible so you could try for a new deal?

"Saturday night soup" was the (often tasty) meal you made out of tads and scraps and bits some one didn't want to finish to clean out the fridge on Saturday night. The challenge was combining the random events and adding seasonings that brought out the best - or at least that minimized the worst.

I guess the family approach to accident was that life had quite a bit of it, but human creativity lay in working with the random elements in ways that were not intrinsic to the raw material.

Amy Charles said...

Digory, do you have recommendations for chaos primers, either general-population or educated-layman?

You can retrodict for quite a long way back, but eventually the resolution of the initial conditions is not enough to specify the pattern at that earlier time

and I take it there's no particular type or category of info that's missing & would make it possible to see how the watch runs all the way back?

I like the soup metaphor, but if we're talking about a nonstop condition, is there a point in your own life where that degree of accident and uncertainty might make you nuts? Apologies to readers who use those words in very specific ways; please feel free to define them more rigorously so us non-scientists can be careful about their use.

Digory said...

Wikipedia has a good overview here:

http://en.wikipedia.org/wiki/Chaos_theory

which includes an extensive bibliography of both technical and popular references. If you can give an indication whether this is at the general level you'd like, or higher or lower, I might be able to make further recommendations.

Yes, these systems are exhibiting behavior that is independent of the precision of measurement.

An interesting intersection that I did not register before reading the article is that it took the advent of computers to develop chaos theory and an understanding of chaotic systems, because it requires so much computation.