Some comments on yesterday's massive earthquake off of the coast of Sumatra, and the ensuing tidal waves that have crashed around the Indian Ocean reminded me of some scientist's description of complexity theory (or chaos theory?) that it is deterministic, not predictive. Which I read as "you know something is going to happen, just not when". The earthquake reporting clarifies what constitutes a prediction. This is from a Washington Post article "When Disaster Strikes" (12/27/2004):

[Caltech geologist Kerry Seih] he knew that, generally speaking, it was getting to be about time for another big one.

But a general forecast of a major quake sometime in the coming decades is not the same thing as a prediction. It's not a prediction unless the time window is so narrow that it can incite dramatic changes in the behavior of people who are vulnerable.

No one has a reliable prediction scheme," said Brian Tucker, president of GeoHazards International, a nonprofit group that tries to reduce the toll of natural disasters in developing countries. "Even if they did, the most reliable prediction would be in terms of probability. So you'd be saying that in the next six months, plus or minus three months, an earthquake of magnitude 6, plus or minus one unit, will occur" -- and even there there'd be uncertainty about the exact location.

"The public can't respond to that. What would a mayor do or a governor do with such a probabilistic prediction?" Tucker said.

jd