[ExI] Feasibility of solid Dyson Sphere WAS mbrains again:

[Keith Henson]

On Fri, Sep 30, 2011 at 5:00 AM, Anders Sandberg <anders at aleph.se> wrote:

> Dennis May wrote:

snip

>> Been through all that kind of discussion before.  Whatever defenses
>> you build the resources outside to overcome them can be as large
>> as it takes.  Beams of diffuse anti-matter dust are my favorite.
>
> It is trivial to overcome any defenses by simply postulating even bigger
> attack resources. But cost-effectiveness will get you.
snip

> anything lesser would find it tough. And if you already have a Dyson,
> the opportunity costs of spending your energy on antimatter to mess with
> the neighbors (aeons in the future, from the subjective timescale of the
> fast processes online) will be very high. You better have a very good
> reason, especially since it is pretty obvious who is responsible.
>
>
> Mbrains will no doubt look quaint as we get ever better ideas of how to
> arrange matter to do useful things, but so far they represent one of the
> more well analysed development directions. If you find them silly, why
> don't you propose a better approach and show us your engineering?

My objection to mbrain is the same I had to jupiter brains, speed of
light delays.  The bigger you get, the slower it thinks.

To get a message to and from a distant part of an 1 Au takes around a
third of an hour.  At 8000+ hrs/year, that's 1/25,000 of a year.
Postulating a million to one speedup, that 40 subjective years to hear
back from a corespondent.

Already we can see our culture spending hundreds of millions of
dollars on new fiber optic cables to shave a few ms off the speed of
light delays between financial centers.  I think hyperfast trading is
a parasitic drain on the economy, but if that is the future, then we
might expect the physical implementation of virtual human civilization
to shrink to the minimum size (a few hundred meters?) consistent with
getting the waste heat from computation out.  Perhaps sunk under a
couple of miles of ocean water to keep it cool.

Unless, of course, we come up with a way to get around the speed of light.

Keith