On Fri, May 25, 2018 at 01:49:24PM +1000, xxxxxx@ozemail.com.au wrote:
> Richard,
>
> I was unclear.
> "Next Thursday in Bitburg" wasn't an example of prediction, but a
> statement of what will happen - total control.
>
> That is impossible with a chaotic system.

Quite the contrary.  By definition, small adjustments to a chaotic
system can have larger effects.  This is not true for non-chaotic
systems: for those, large changes always need large adjustments.  The
better one understands the internal behaviour of a chaotic system, the
less external influence is required to guide it toward a desired state
path.

So the chaotic nature of the system is exactly what allows any hope of
controlling it with adjustments of scale much less than those of the
entire system.

> So even with the fleet of spinal-mount equivalent weather control
> devices, there's a chance of unwanted outcomes - which increases the
> more you fiddle with the system and the shorter the time interval
> between measurements/interventions.

Completely the opposite.

The more measurements you take and the more frequent they are, the
better your model can be and the better your potential for control.
Likewise the more frequently you apply corrections, the less intensive
they need to be.  The longer between measurements or adjustments, the
more chance there is that some unknown small influence will snowball
up into a deviation too large for your control systems to return it to
the chosen path.

In short: chaotic systems have much shorter prediction horizons than
non-chaotic systems when uncontrolled.  But with guidance, they are
easier to control with frequent enough measurements and adjustments.

- Tim