Blacknad.

I'd just like to comment on this:

"Is the weather truly indeterminate? If we had all possible variables are you sure we could not predict it accurately?"

The problem of predictability in chaotic systems is something that has become known as 'the butterfly effect'. The weather is an example of what's called 'a chaotic system', and the butterfly effect takes its name from the fact that some very trivial event such as a butterfly flapping its wings can eventually have an effect on the weather. The point is that the behaviour of a chaotic system is highly dependent upon initial conditions. The smallest variation in those conditions causes a very much greater variation in the system with the passage of time. For this reason, although the accuracy of weather forecasting can undoubtedly be greatly improved by the use of supercomputers to analyse the data, the limitation will always be the data itself. For total accuracy, there would need to be an infinite number of sensors, and infinite computing power. My understanding is that there will probably never be enough data to provide for reasonably accurate forecasts beyond a few weeks. I think I may not be explaining this too well. I can recommend an excellent book by James Gleick called 'Chaos - Making a New Science', published by Penguin Books in 1988.

From Wikipedia:
"In mathematics and physics, chaos theory describes the behavior of certain nonlinear dynamical systems that under certain conditions exhibit dynamics that are sensitive to initial conditions (popularly referred to as the butterfly effect). As a result of this sensitivity, the behavior of chaotic systems appears to be random, because of an exponential growth of errors in the initial conditions. This happens even though these systems are deterministic in the sense that their future dynamics are well defined by their initial conditions, and there are no random elements involved. This behavior is known as deterministic chaos, or simply chaos."

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

see also:
Chaos Theory: A Brief Introduction
http://www.imho.com/grae/chaos/chaos.html
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Terry. Thanks for the links. I've downloaded the 'motherjones.com'. I'll read through it later.


"Time is what prevents everything from happening at once" - John Wheeler