[ExI] Physical limits of electromagnetic launchers

[Anders Sandberg]

On 2012-06-07 00:39, Jeff Davis wrote:
> If the probe is inbound to a technologically advanced star system,
> then one can avoid braking entirely by transmitting a "virus" that
> hijacks a bit of the local manufacturing capacity.  It should be
> possible to determine ahead of time -- perhaps even prior to launch --
> if the destination system has the needed tech.  Then the probe listens
> and evaluates en route, and configures the virus accordingly.  Some
> thought might be given as to whether this is excessively "unfriendly".

Yes, this works if you just want to go where there are already an 
installed infrastructure. It is not useful if you happen to be the first 
civilization to expand or if you want to colonize *everything*. It is 
useful if you care mainly about existing civs - either as competitors or 
as friends.


We have been thinking about wild approaches to arriving at destinations 
like shining lasers at it to induce the formation of a crude replicator 
that builds a better one with a receiver and then remote-directed 
construction, but I have not seen any compelling arguments that this is 
feasible (and diffraction limits suggest it is not possible - you can't 
get enough resolution over the distance unless you have an absurdly 
large transmitter and very short wavelengths). In fact, it would be a 
very interesting research project to delineate just how much fine 
manipulation is possible over distance using different energy levels, 
wavelengths etc. My conjecture is that unless the substrate is designed 
for it (i.e. an empty computer waiting for a command) nearly all forms 
of complex manipulation have to be local.


-- 
Anders Sandberg
Future of Humanity Institute
Oxford University