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- Path: sparky!uunet!stanford.edu!agate!darkstar.UCSC.EDU!darkstar!steinly
- From: steinly@topaz.ucsc.edu (Steinn Sigurdsson)
- Newsgroups: sci.space
- Subject: Re: Propulsion questions
- Date: 22 Jul 92 17:35:23
- Organization: Lick Observatory/UCO
- Lines: 34
- Message-ID: <STEINLY.92Jul22173523@topaz.ucsc.edu>
- References: <1992Jul16.154632.15534@wpi.WPI.EDU> <BrHtC3.29y@zoo.toronto.edu>
- <BrKIJJ.CKH@watdragon.waterloo.edu> <rmartin.711643766@thor>
- <NICKH.92Jul20115850@VOILA.VENARI.CS.CMU.EDU>
- <rmartin.711737055@yosemite>
- <NICKH.92Jul21150202@VOILA.VENARI.CS.CMU.EDU> <rmartin.711834955@thor>
- NNTP-Posting-Host: topaz.ucsc.edu
- In-reply-to: rmartin@thor.Rational.COM's message of 22 Jul 92 19:55:55 GMT
-
- In article <rmartin.711834955@thor> rmartin@thor.Rational.COM (Bob Martin) writes:
-
-
- nickh@CS.CMU.EDU (Nick Haines) writes:
-
- >In article <rmartin.711737055@yosemite> rmartin@yosemite.Rational.COM (Bob Martin) writes:
-
- > [about a black-hole drive]
-
- > Can anybody tell us the efficiency of this with respect to a fusion
- > drive?
-
- >I can guarantee that the answer to that question is "no". I mean, it
- >might be a neat idea, but we're not going to have a decent figure for
- >the efficiency of it until we've actually got a small black hole to
- >play with.
-
- Allright then, does anybody have a theoretical model that might shed
- some miniscule light on this subject? (Sheesh!)
-
-
- Penrose mechanism. Can't remember actual number but you recover
- about 30% of rest mass energy. Main problem is that minimum stable
- mass is uncomfortably heavy - particularly if you want a primordial
- black hole that's been around a Hubble time - that's if Hawking's
- right.
- Of course if he is, and you can _create_ a m < m_HubbleBH
- black hole you recover almost 100% of the rest mass as it evaporates
- ;-)
-
- | Steinn Sigurdsson |I saw two shooting stars last night |
- | Lick Observatory |I wished on them but they were only satellites |
- |steinly@helios.ucsc.edu|Is it wrong to wish on space hardware? |
- | "standard disclaimer" |I wish, I wish, I wish you'd care - B.B. 1983 |
-