[ExI] The Great Silence again

[Damien Broderick]

On 4/26/2011 3:54 PM, spike wrote:

> ...if the nodes of an MBrain were to orient themselves
> to reflect most of the light from the star toward the east, then the star is
> very slowly dragged to the west, by conservation of momentum.  It really is,
> although I recognize it strains the imagination.
>
> Robert rejected the notion, based on his firm belief (very possibly true)
> that an MBrain would never waste available energy just to drag the star
> elsewhere, even if there existed something really cool at the other end such
> as another MBrain.

He changed his mind a bit in his essay for my book YEAR MILLION. 
Annoyingly, I lost the final text of the thing in disk crash a while 
back, and only have (I think) his early draft. Where he says...

<The path of a solar system could be redirected, but that took an 
enormous amount of energy. Equally enormous amounts of computational 
time were devoted to computing useful future paths, so as to minimize 
the energy required to copy information. For every technological 
civilization in the galaxy, a burning question was when its natural 
orbit would take it to a location optimal for replication. The choice 
was whether to consume greater amounts of energy and matter redirecting 
a solar system to a near term replication point, at the cost of becoming 
a lesser civilization--or to wait, accumulate the maximal amount of 
knowledge and history, and duplicate that during the next chance 
encounter with one of the nearby solar systems. The choices were highly 
civilization-dependent. Where were you in the galaxy? What was one's 
forward path over millions of years? Was it possible to scrounge matter, 
and therefore the material to store knowledge, from near misses with 
developing stellar nebula? Each of these questions had to be answered on 
a civilization by civilization basis.>

Damien Broderick