[ExI] Fermi question, was is a FTL drive a dream . . .

[Anders Sandberg]

On 2011-12-21 10:44, Eugen Leitl wrote:
> On Wed, Dec 21, 2011 at 09:57:36AM +0100, Anders Sandberg wrote:
>> Which assumptions in the scenario make no sense?
>
> Basically almost every assumption is ad hoc. It's something an
> economist would write, who is accustomed to deal with a narrow scope of
> interactions among members of a single local species.
>
> You think the http://hanson.gmu.edu/filluniv.pdf paper is good, yes?

It is a start. So you don't think the assumption that the propensity for 
colonizing is partially "inherited" from the parent civilization would 
be true?


>> Some interesting questions about the visibility of probes slowing down.
>> Continous antimatter rockets would show a very unusual signature of
>> blueshifted annihilation plus blackbody radiation, but Drexler suggested
>> something more akin to backwards pointing railguns that might be far
>> harder to see.
>
> Do you disagree that the anthropic principle prevents observation
> of relativistically expanding preexpansive observer-extinguishing
> fronts very effectively?

Not really. It prevents us from being inside the front, and might 
(depending on our views on SIA/SSA) bias our probabilities towards 
universes where there are a lot of observers (i.e. no fronts) or where 
we are first. It is a bit like my anthropic shadow paper: the fact that 
we cannot have giant meteor impacts in our recent past doesn't make them 
less likely or invisible in the present.


-- 
Anders Sandberg
Future of Humanity Institute
Oxford University