Billy Brown wrote:
>
> Dan Clemmensen wrote:
> > If we are willing to believe that nanotech permits at least some way to
> > build large structures using multi-generation assembler production techniques,
> > then it should be possible to send arobotic probe to the Oort cloud and find
> > a very large comet or a bunch of smaller comets, aggregate them into a
> > large mass, add reaction engines, and direct the resulting mass into a
> > cometary orbit that intersects the earth. Just how do you intend to defend
> > against this? There are a great many alternative attacks: this is just
> > the first one I happened to think of.
>
> By using the same technology, of course. While your robots are journeying
> to the Oort cloud and diverting comets, mine are mining the moon to build
> defensive systems in high orbit. A multi-gigaton warhead will convert a
> comet into a cloud of gas quite nicely. If you build missile defenses on
> the comet, we can use directed energy weapons instead (burn one side of the
> comet to push it off course - or just shoot off your missile defenses and
> nuke it). I have far more mass to play with than you do, which lets me
> build bigger and better hardware.
I chose to build my weapon in the Oort cloud specifically to keep you from knowing what I was doing, and to give myself stealthy access to more mass than you have readily available. I also get the advantage of throwing my planet-sized mass down a steep gravity gradient giving you an essentially impossible task. The only way you can stop me is to organize your entire set of resources into a single defensive and surviellance effort, to keep track of all of my efforts to destroy you. That is inconsistent with the concept of complete freedom of action for millions of individuals. Any weapon you can build and use to defend against an earth-massed weapon can be used against the earth, also.