Re: Weather

Anders Sandberg (
Sun, 2 Feb 1997 11:14:19 +0100 (MET)

On Sat, 1 Feb 1997, Chris Hind wrote:

> I myself think weather control will come long before decent
> weather prediction. With predicting the weather you have to watch, wait,
> and look at all the little details to predict where moisture and such is
> going to move. With weather control all you need to do is heat up sections
> of the atmosphere accordingly to FORCE the system to put out what you want.

Hardly. Unless we are talking megaengineering, the weather contains so
large amounts of energy that it would be very costly and inefficient to
force the system in the direction you want - a cubic kilometer of air
moving at the leisurely pace of 1 m/s would contain 5*10^8 J of just
kinetic energy.

What you can do is of course physical juijitsu - redirect the energy
slightly in an useful manner and let physics take its course. This is
how control of chaotic systems work, and it seems to me that the only
workable large scale weather control methods would be based on nudging
the weather into the right attractor instead of trying to force it there
(which is bound to cause chaotic oscilliations and other trouble).
Managing microclimate is another thing (I like Daedalus suggestion about
using microwaves to force rain from clouds to keep them away from certain

This relates to weather prediction, of course. The reason we can't
predict the weather well is that it is too chaotic. Even if we did get
enough sensors to keep track of it on a quite local scale it would still
surprise us after a while; judging from the lyapunov exponents I have
heard of detailled predictions beyond a week are simply not possible
unless you place several sensors in every cubic kilometer.

Chaotic dynamics is both our friend and foe; fortunately we can use its

Anders Sandberg Towards Ascension!
GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y