Eliezer S. Yudkowsky wrote:
> Now _this_ is something I dealt with last time. If you take a lot of
> lasers, maybe (for nanotech) a solid sphere-surface of hyperefficient
> quantum-well lasers, all pointing inward, you can zap a pellet of
> deuterium ond it will fuse. The last time I suggested it on
> the group, someone else wrote back that I'd disclosed something he was
> going to patent.
It might work for the trigger, if you can make it small enough. That would remove the need for plutonium, but you still need a very large amount of deuterium and/or tritium to get a large explosion.
> As for power, there are all kinds of burnables in the Earth; or if not
> that, you can use geothermal, the energy differential between one mile
> down and ten miles down. As for getting geotherm set up, I'm
> sure that you can build some pretty efficient electrochemical batteries
> and charge 'em up beforehand. If you've got a large enough resource
> base you could give 'em a small supply of antiprotons. (Remember the
> antimatter leak at Fermilab? 10^12 antiprotons - almost bright enough to
> see, I think.)
You can't burn anything 1,000 meters down - no oxygen, right? Antimatter reactors are possible, but would have to be rather large (you need to absorb the gamma radiation to capture the energy, and that takes a lot of matter). Conventional batteries don't hold enough power to dig themselves down to a deep construction site. IMO, your best bet is actually to drop a power line from the surface - you'll need a small pipeline to move material in and out of the worksite anyway. Failing that, build a burrowing robot with a nuclear reactor. Either way, however, you need something much bigger than a pack of nanobots.
> And remember, the best place to find deuterium is in the
> unoccupied and already-pretty-noisy oceans.
True enough - but to make gigaton-range weapons you need *tons* of the stuff, and probably tritium as well. Even then, you need several dozen bombs to do a good job of wrecking the world (or hundreds, if diamondoid buildings are common). Its hard to collect that much without making it obvious what you're up to - either your robots end up hot enough to show up on orbital surveillance, or you end up with a lot of gigantic, heavily-shielded vehicles that the neighbors are going to wonder about.
Billy Brown, MCSE+I
bbrown@conemsco.com