Re: Fate of SF as World Slides Down Back Side of Hubbert's Curve?

On Mar 25, 11:03=A0am, jdnic...@[EMAIL PROTECTED]
 (James Nicoll) wrote:

> =A0 =A0 =A0 =A0 Somewhere or other (probably on the dead PC) I have a
pdf
> of a paper that studies the possibility of harvesting antimatter from
> natural sources in the solar system. The quantities involved are
> disappointingly small, 25 nanograms per day per collector. That's
> interesting from an interplanetary propulsion perspective but not
> so much if you want an interstellar rocket. =A0

I don't understand why anyone is excited about this amount for
any purpose.  E=3Dmc^2, right?  Okay, let's double that since
we're talking anti-matter here (and ignore loss to neutrinos and
other annoyances).  We get

E=3D2 * 25E-12kg * 3E8m/s * 3E8m/s /day
=3D450E4 joules/day ~=3D 52 watts

That's about as much power as you'd get from 52 grams of
solar panel, at 1kg/kW.  Even assuming perfect 100%
efficient harvesting of anti-matter, solar electric seems to
totally beat the pants off of it.  And solar electric is already
flying real life interplanetary missions.

Sure, a small amount of anti-matter can translate to a lot
of energy, but a REALLY small amount of anti-matter still
translates to a small amount of energy.

Isaac Kuo