[ExI] libertarian (asteroid) defense

[Damien Sullivan]

On Mon, Feb 28, 2011 at 11:19:17PM +0000, Anders Sandberg wrote:
> Damien Sullivan wrote:
> >Actually I imagine volcanoes might pretty tameable.  Drill down and
> >release gases/magma in a controlled manner, rather than letting them
> >blow all at once.  Though the BP oil spill highlights the safety
> >concerns of drilling into a pressure chamber.  Would want to practice on
> >the small volcanoes first.

Oh cool, you give the first response I've gotten to this that isn't a
simple "cool" or "that's silly".

> I think there is a bit of a problem with this method. A typical
> volcano has a lava chamber on the order of a cubic kilometer and
> contains up towards 10^19 Joules or so. A drilled hole has a
> diameter ~0.1 m. Assuming blackbody radiation from 2000 K lava only
> allows 9000 W to escape the hole. Pumping up something like hydrogen
> (thermal capacity 20 kJ/kgK) at the speed of sound (~1300 m/s) at a
> density of 1000 kg/m^3 gives an energy flux of 520*10^9 W, able to
> defuse the volcano in a year or so... assuming the massive erosion

Those seem like silly mechanisms, especially radiation, though they give
a bracket, I guess.

I'd envisioned letting CO2 out, to lessen the pressure; letting lava
come up and cool; pumping water down, so you're both cooling the chamber
and recouping or even generating geothermal power.  And no need to be
limited to one hole.

> turn it into a steam vent leading to the volcano boiling off (the
> risk is alway a sudden pressure decrease in the chamber, since then
> gases start to release in the lava and it spurts out).

Ah, tthat's good to know.  I've never studied vulcanology much.

> Garden variety volcanos are anyway not big threats except to locals
> and airlines. It is defusing supervolcanos we ought to seriously

Well, the high end of ordinary volcanoes can bobble climate and
agriculture for a year or three.  Survivable in a robust system but an
unfortunate extra stress at bad times.

Speaking of robustness, I was appalled to investigate and learn that the
US doesn't seem to have a strategic food reserve.  I think we used to,
but now we trust to the markets, as if markets will provide food in the
case of a global crop failure.  Well, we can pay more, but still.
Weren't public granaries one of the first services of non-thuggish
government?

> think about, but the liability problems of getting them wrong are...
> severe.

Yeah.  Of course, getting surprised by one is also severe.  But I guess
no *liability*.

> Most common natural GCRs are fairly manageable if you can warn ahead

GCR = global catastrophic risk

-xx- Damien X-)