Date: Thu, 8 Oct 92 05:04:26 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #298 To: Space Digest Readers Precedence: bulk Space Digest Thu, 8 Oct 92 Volume 15 : Issue 298 Today's Topics: Black holes, Sci-Fi Channel Blue Danube Don't forget Other Guy(was Re: Von Braun -- Hero, Villain, or Both?) Impact in AD 2000? Need info: Fault-Tolerant Spacecraft systems (VLSI-related) SETI positive? UFO EVIDENCE VS. Carl Sagan Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 8 Oct 92 02:16:18 GMT From: John Roberts Subject: Black holes, Sci-Fi Channel Newsgroups: sci.space -From: higgins@fnalc.fnal.gov (Bill Higgins-- Beam Jockey) -Subject: Re: BLACK HOLES -Date: 5 Oct 92 17:05:58 GMT -In article <1992Oct5.051549.1528@ccu.umanitoba.ca>, umwu0014@ccu.umanitoba.ca (Charles Bo Wu) writes: -> In <2523.2ACF3744@catpe.alt.za> Sasha.Degner@f5.n7103.z5.fidonet.org (Sasha Degner) writes: ->> ->>1) What exactly are black holes? ->>2) Is there any truth in the theory that they may be created by alien ->>life forms? ->>3) Is there a black hole close to our galaxy? -> -> I suggest you to read the book "A Brief History of Time" by -> Stephen Hawking. An excellent book that tells you just about anything a -> normal person would want to know about black holes and the Universe. -I haven't read this book, but I doubt it provides a direct answer to -question number 2. By the way, black holes are not universally accepted - they're not nearly as well-established as neutron stars, for instance. There are some very good candidates, including some found by HST, for which a black hole is considered a more likely explanation than any alternates that have been proposed. It is hoped that WF/PC2 will be able to provide considerable additional evidence. (I may be overstating the uncertainties a little - the majority of astrophysists believe they exist, and lack of solid proof is probably largely because they're hard to observe.) The literary reference reminds me - the long-awaited Sci-Fi Channel is now up and running. It's mostly fiction, but it also has some science fact shows, including "The Science Show" and "Inside Space" - the latter hosted by a famous science fiction celebrity. Last week's episode included a segment on virtual reality (with interesting video), and a clip from the *movie* "A Brief History of Time", which is apparently narrated by the author. (!) On an amusing note, flipping past the Sci-Fi channel this weekend, I came across the first images I've ever seen of Brent Spiner without his "Mr. Data" makeup. [And they show "Stingray" every weekday morning!] John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Thu, 8 Oct 1992 04:47:44 GMT From: James Davis Nicoll Subject: Blue Danube Newsgroups: sci.space In article jay@deepthot.cary.nc.us (Jay Denebeim) writes: >In article , Jeff Bytof writes: > >> >For some strange reason, I have visions of sleek Pan Am >> >(RIP) 'liners slowly spinning across a starfield. Have I gone nuts, or should >> >I put up my 2001 tape for a while? >> I'd say for about 100 years. > >If its 100 years, its forever. We'll run out of enough energy to put the >first SPS up if we don't start much sooner than that. > Nonsense. Fission should be sufficient. Granted its PR sucks, but experience shows that people will choose possible environment problems over probable economic hardship: look at the history of the laws governing coal use in England in the last few centuries. James Nicoll ------------------------------ Date: 8 Oct 92 01:11:39 GMT From: Steinn Sigurdsson Subject: Don't forget Other Guy(was Re: Von Braun -- Hero, Villain, or Both?) Newsgroups: sci.space In article <1992Oct6.195549.1733@kopachuk.uucp> dcb@kopachuk.uucp (David Breneman) writes: If it hadn't been for inter-department politics in the US government, the Soviets would have had the *second* satelite, but the US was (as stated policy) in no hurry, and the Soviets wanted to be first at all Actually I like the rather devious argument I first heard recently - probably on the net ;-) - that the US was quite happy to be second as they wanted the Soviets to establish precedent on limits to airspace, at the time it was not clear if air space restrictions extended up to orbit, would have been most inconvenient if pushed by somebody like the Soviets. But then again I doubt anyone had much of a coherent policy taking such factors into account... | Steinn Sigurdsson |I saw two shooting stars last night | | Lick Observatory |I wished on them but they were only satellites | | steinly@lick.ucsc.edu |Is it wrong to wish on space hardware? | | "standard disclaimer" |I wish, I wish, I wish you'd care - B.B. 1983 | ------------------------------ Date: 8 Oct 92 01:28:42 GMT From: John Roberts Subject: Impact in AD 2000? Newsgroups: sci.space -From: szabo@techbook.com (Nick Szabo) -Subject: Re: Toutatis impact in 2000 AD? (was Re: Help !) -Date: 5 Oct 92 06:55:07 GMT -In article <1992Oct1.160708.26767@kakwa.ucs.ualberta.ca> martin@space.ualberta.ca (Martin Connors) writes: ->[Earth's diameter is] ->000044 AU so even if Toutatis was coming in randomly within a circle of ->radius 0.011 AU the geometrical chances of impact would be about ten in a ->million. Maybe double that for gravitational focussing. -This translates to (2e1/1e6)*(5e9) or 10,000 dead people, actuarily -speaking, or 0.2 per 100,000 population. The death rate from -airline crashes is 0.04 per 100,000 people. Translated into -more meaningful terms, in the year 2000 each of us has five -times as much chance of being killed by Toutatis as dying in an -airline crash. Presumeabely a more accurate orbit has or soon will -be predicted, so that we can do a better analysis than -the quoted, which uses the expected miss distance as the measurement -error. I notice you kill just about everybody on the planet, no matter where the impact. An impact of a two-mile-diameter asteroid would be pretty severe, but I'm not sure it would be quite *that* bad. Isn't that only about a tenth of the mass of the alleged "dinosaur killer" asteroid? The analysis you refer to is apparently just a worst-case scenario - it wasn't meant to reflect the actual uncertainty in the trajectory. I believe a later post gives the uncertainty as a fraction of an Earth radius. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 7 Oct 92 22:02:26 GMT From: Pascal Gosselin Subject: Need info: Fault-Tolerant Spacecraft systems (VLSI-related) Newsgroups: sci.space As a requirement for a VLSI architecture I'm taking this semester, I'd like to write a paper on the types of fault-tolerant architectures required on Spacecraft. I am interested in both the hardware and software aspects of these systems with emphasis on VLSI's role in all of this (i.e. impact of harsh environments on system reliability, effects of radiation, etc...). I have been discouraged somewhat by my teacher, as he thinks most of the documentation on the subject is probably classified. Replies by email. Thanks. -Pascal -- +--------------------------+-------------------------------------------------+ Pascal Gosselin | Communications Accessibles Montreal pascal@CAM.ORG | A non-profit corporation. Newsfeeds & More. Apple Support Specialist | For info: info@CAM.ORG or Voice (514) 923-2102 ------------------------------ Date: 8 Oct 92 01:23:49 GMT From: Paul Colley Subject: SETI positive? Newsgroups: sci.space,sci.astro In article <7OCT199215545204@csa2.lbl.gov> sichase@csa2.lbl.gov (SCOTT I CHASE) writes: > For example, using this detector at 100 light ^^^ >years from Earth, you could not detect the random TV and radio signals that ^^ >we have inadvertantly transmitted out into space. Oh, drat. All those fascinating 1890's television shows going unnoticed. ^^^^ I suppose I'd be more worried if somebody a 100 light-years from Earth WAS currently watching our TV broadcasts! ----- I know, I know, Scott meant "100 years from now.... this equipment wouldn't detect our current radio and TV broadcasts at a 100 light-year distance". - Paul Colley University: colley@qucis.queensu.ca Home: pacolley@ember.uucp watmath!ember!pacolley +1 613 545 3807 [...] "Sorry, I'm all booked up." "Who was that?" "The library." - B.C. ------------------------------ Date: 7 Oct 92 12:48:11 GMT From: nicho@VNET.IBM.COM Subject: UFO EVIDENCE VS. Carl Sagan Newsgroups: sci.space In Jeff Bytof writes: >(I am of course referring to Dr. Sagan's hobby interests - "ethical ============ Has Carl Sagan actually got a doctorate in anything ??? Last I heard (long time ago , true) he was just plain ol' C. Sagan ----------------------------------------------------------------- ** Of course I don't speak for IBM ** Greg Nicholls ... nicho@vnet.ibm.com or nicho@cix.compulink.co.uk voice/fax: 44-794-516038 ------------------------------ End of Space Digest Volume 15 : Issue 298 ------------------------------