[extropy-chat] Dark matter and ET

[Robin Hanson]

At 10:51 PM 7/14/2005, Dan Clemmensen wrote:
>An SI will expand beyond its natal solar system only if The NPV of the 
>knowledge gained by use of the extrasolar computational power exceeds the 
>NPV of the computational resources to be invested in the expansion. 
>Example: the SI might expend an asteroid's worth of comptutronium to 
>colonize a star system 4 light-years away.  Using a speed-of-light probe, 
>at best is takes 4 years to initiate the colony, and at best the colony 
>starts with a knowledge base that is four years old. The SI will not get 
>any new input for at least eight years, and the new input will be four 
>years old and will be based on an eight-year-old knowledge base. The SI 
>may very well conclude that it will gain more knowledge by incorporating 
>the asteroid's worth of compturonium within itself rather than launching 
>the probe. If this is generally true, then we would not expect to see any 
>expanding spheres. Instead, we will simply see systems going dark.

This is a clear example, where, as I warned, predictions depend on your 
assumptions about the goals/priorities of the alien civilization.  You 
assume the only point of colonization is to spawn a computational 
sub-process, where you already have the needed inputs.  This gives very 
different predictions from a civilization whose goal is to colonize as far 
and fast as possible, for example.

A robust way to forecast alien goals/priorities is to just predict a wide 
divergence of such goals.


Robin Hanson  rhanson at gmu.edu  http://hanson.gmu.edu
Associate Professor of Economics, George Mason University
MSN 1D3, Carow Hall, Fairfax VA 22030-4444
703-993-2326  FAX: 703-993-2323