Re: starship-design: Anti-antimatter

["L. Clayton Parker" <lparker@cacaphony.net>]

Hi Ken,

Just a few quick observations on your ideas and questions.

> some sort of theoretical minimum matter/antimatter ratio, just from 
> containment considerations.  Anyone want to tackle that one?

Theoretical efficiencies don't look promising...we won't even get into the
problem of producing antimatter on an industrial scale...

> 	The first is probably the most easily shot down: power the ship 
> from an enormous relativistic or near-relativistic flywheel.  There's a 

Hmm, you mean like a rotating black hole? I think Robert Forward has
already proposed this one. Check out a few of his books. Bear in mind that
now you have to accelerate the mass of the black hole also...and anything
spinning at relativistic speeds is going to have the same mass moments as a
black hole anyway...

> 	Idea #2:  Catalyze nucleon decay using captured magnetic 
> monopoles.  

I think Forward beat you to this one also...

> continually converts them into pure energy.  You'd probably need quite a 
> few monopoles to make a decent spaceship engine, but it'd be a whole lot 
> less than the needed amount of antimatter.

Definitely.

Since we are dreamig here, I want to throw one more hypothetical propulsion
mechanism into the pot (and I know it has already been speculated upon). 

The biggest problem with interstellar propulsion is finding a method that
is simultaneously capable of generating lots of thrust (ISP) and not adding
tremendous amounts of mass to the vehicle. The trick here is to find a
mechanism that like a solar sail, relies upon an external source of power
which we can tap directly or indirectly for propulsion. This source needs
to be large, inexhaustible, and NATURALLY produced, i.e. we don't have to
make it, correlate it, or concentrate it as in beamed power.

What we need is to be able to unfurl a solar sail billions of miles across
that weighs NOTHING, or surf on a wave of gravity, or ride on a stream of
neutrinos, or... I really don't have a preference as long as the mechanism
for tapping the source of power requires somewhat less than astronomical
(and unrealistic) amounts of energy.

There is no currently known or speculated propulsion mechanism utilizing
onboard fuel that will provide realistic interstellar propulsion so maybe
we need to look elsewhere.

Lee