From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Fri Jul 21 2000 - 16:16:25 MDT
On Fri, 21 Jul 2000, Amara Graps wrote:
> David R. Criswell, yes?
Yep.
> I just put the pieces together that he is the same D.R. Criswell that
> did so much work on the electrostatic transport of lunar dust in the
> 70s. He's kind of famous for that work.
Yep, he is a serious scientist, which is why stellar husbandry
has to be seriously considered as possible.
> The paper that you (Robert) have by Criswell, is this the same as the
> chapter: "Solar System Industrialization Implications for Interstellar
> Migrations" in the book: _Interstellar Migration and Human
> Experience_?
Yep, thats the paper.
> email is not such a reliable method to reach me these months
> (PhD endpoint near), phone and in person is better.
Amara, don't your filters raise the priority of messages with
the name "Amara" in them? That's a distinct advantage to having
a unique name! :-) I'm moderately sure Robin is bumping up messages
that say Robin in them (either that or he's got a email-to-brain
interface that is a bit faster than the rest of us).
[snip great astrophysics lesson (no tuition required)...]
> For a moderate mass star, say 5*M_sol, the picture proceeds as
> above. [snip]
Aha, but a 5*M_sol star, is unlikely to have a terrestrial type
civilization around it (lives too short, higher temps & winds
blow dust out of the system sooner resulting in potentially
less planet formation, etc.).
Getting back to the Criswell-Lorry (in lieu of the real disputant)
debate, the question is whether a typical advanced civilization
around probable civilization class stars (See Dole-Asimov,
Planets for Man & subsequent works), that have a reasonable liquid
water zone. For that we need to know what are the limits of star
lifting/stellar husbandry for stars that may never initiate the
higher levels of nucleosynthesis.
Put another way -- what are the limits on whether you can drive
the star from F --> G --> M --> L class? There may be some
benefits (100's of millions of years to billions of years),
that would create a benefit > cost situation that justifies
the effort, even if you cannot ultimately prevent a supernova.
Robert
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