Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from holmes.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Tue, 23 May 89 05:17:10 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 23 May 89 05:17:01 -0400 (EDT) Subject: SPACE Digest V9 #454 SPACE Digest Volume 9 : Issue 454 Today's Topics: Re: New Orbiter Name Announced Re: New Orbiter Name Announced PHONE TREE ALERT Re: Sun's invisible partner NEMESIS Re: Andromeda Strain Re: citizens in space -- risk silliness Ballistic parachutes (was: Giotto) Re: Andromeda Strain Re: SPACE Digest V9 #432 Re: SPACE Digest V9 #443 ---------------------------------------------------------------------- Date: 20 May 89 13:01:48 GMT From: bfmny0!tneff@uunet.uu.net (Tom Neff) Subject: Re: New Orbiter Name Announced Two notes on the Endeavour/Endeavor mix up (NASA *would* snatch confusion out of the jaws of clearness now wouldn't they?? ) 1. The schools that submitted names split (unevenly) between the British and American spellings also. Evidently some of them had trouble reading their predigested NASA "curriculum materials." The original vote tallies article has expired here, perhaps Peter could repost it for posterity. 2. AvWeek said 'Endeavor' in its announcement of the name selection. -- Tom Neff UUCP: ...!uunet!bfmny0!tneff "Truisms aren't everything." Internet: tneff@bfmny0.UU.NET ------------------------------ Date: 19 May 89 18:12:47 GMT From: hpfcdc!hpfcdj!myers@hplabs.hp.com (Bob Myers) Subject: Re: New Orbiter Name Announced >The ultimate reusable booster!!! >It never leaves the ground. Needs no refurbishing before reuse. >No need for downrange recovery ships, aircraft, or crews. >Probably exceeds local noise limits, though. But was the Columbiad an "assault rifle"? :-) Bob "Of course, our fine, upstanding American hunters NEED 900-foot-long rifles for SPORTING PURPOSES!" M. ------------------------------ Reply-To: mordor!rutgers!pnet01.cts.com!jim@angband.s1.gov Date: Sat, 20 May 89 09:43:20 PDT From: mordor!rutgers!pnet01.cts.com!jim@angband.s1.gov (Jim Bowery) To: hplabs!hpcea!hp-sdd!crash!space@angband.s1.gov Subject: PHONE TREE ALERT Phone Tree Alert Date: 5/20/89 Subject: Terminate spending for NASA's space station program Target: Rep. Jamie L. Whitten, Chairman House Committee on Approrpriations Address: Hon. Jamie L. Whitten U.S. House of Representitives Washington, DC 20515-2401 202-225-4306 Message: Call or write Chairman Whitten expressing your support for his opposition to further wasteful spending on NASA's space station project. The Senate goes out on Memeorial Day recess on 19 May and the Hous goes out on 25 May. Therefore, activists have until the 25th to target the chairman of this important committee. Activists should also try to make appointments with their congressional representatives durring this recess. The next several weeks will be crucial to showing the political leadership that Americans want a space program which they can be proud of! Add'l Brief: In your letter or call, try to relate the waste on the space station program to fact that while his favorite programs are being cut to the bone, NASA and aerospace contractors are posing as a grassroots space activist network to ensure continued budget inflation for themselves. For tips on how NASA and aerospace contractors are successfully posing as grassroots activists, read the Space Activists Handbook, available from SPACEPAC. Write or call David Brandt at NSS HQ. Or inquire on this net to Jordan Katz. --------------------------------------------------------------------------- Jim Bowery Phone: 619/295-8868 PO Box 1981 Join the Mark Hopkins Society! La Jolla, CA 92038 (A member of the Mark Hopkins family of organizations.) UUCP: {cbosgd, hplabs!hp-sdd, sdcsvax, nosc}!crash!pnet01!jim ARPA: crash!pnet01!jim@nosc.mil INET: jim@pnet01.cts.com ------------------------------ Date: 19 May 89 20:49:45 GMT From: jtk@mordor.s1.gov (Jordan Kare) Subject: Re: Sun's invisible partner NEMESIS In article <13140@ut-emx.UUCP> nather@ut-emx.UUCP (Ed Nather) writes: >In article <13325@swan.ulowell.edu>, devans@hawk.ulowell.edu (Daniel Evans) writes: >> A couple of years back, I had read some accounts about a tiny (non- >> identical) "twin" of our sun, which swings by every few million years or so. >> Someone referred to it as "Nemesis". >> How much evidence is there supporting this theory? > >None. >> What are the details? >There aren't any. >> How did they decide what its path is? > >They were trying to explain "periodic" mass extinctions in the fossil record >by invoking comets to smash the earth and create a "gravitational winter" by >ruining the earth's ecology, on a regular basis. The "periodicity" was, at >best, suspect, but why not try? They invoked the mythical "Oort cloud" of >comets that supposedly (and invisibly) surrounds the solar system, and placed >the mythical "Nemesis" in an orbit that would perturb them periodically, thus >raining destruction on our unsuspecting planet and its inhabitants. > Oh, come now! I take it, Ed, that you will not consider Nemesis to exist unless/until it is directly observed. Does this mean you won't accept the existence of electrons until someone takes a photograph of one? The Nemesis hypothesis postulates that the Sun is part of a binary star system. At perihelion (closest approach to the Sun), the companion passes through the quite non-mythical Oort cloud (a large and only roughly-defined region surrounding the Solar System where, based on numerous observations of first-pass and long-period comets, most comets appear to originate). The companion is big enough and slow-moving enough to "scramble" the orbits of many comets, some of which fall into the inner solar system (most are ejected into deep space). This creates a "comet shower" lasting of order 1 million years, during which the Earth is much more (10x) likely to be hit by a comet than usual. The existence of Nemesis was proposed to account for a 26 million year periodicity in the fossil extinction record, combined with strong evidence that at least one extinction (the Cretaceous-Tertiary, 65 Myears ago) was caused by some sort of large-body impact). The periodicity (with some changes in best-fit timing) remains statistically significant after several years of (often very skeptical) analysis; the most recent results involve tracking the extinction rate for some 10,000 genuses (originally only a few hundred families were tracked). The theory made several predictions, notably that impact craters would also be found to be concentrated at regular time intervals, and that multiple impacts would occur at each extinction, spread over of order 1 Myear. (since, if at least one impact occurs on each "pass", the "average" number of impacts must be greater than one). The known orbital period gives the size of the orbit: the major axis of the orbit is 2.7 light years. The requirement to go through the Oort cloud gives a "most probable" ellipticity of about 0.7, as I recall. Passing stars "frequently" (every few Myear) come closer than the companion to the sun, but they have relatively high velocity (they're not bound to the Sun) and do not strongly perturb either the companion or the comet cloud. Over about 1 billion years, though, they would be expected to disrupt such a weakly bound pair; this means that either the companion was only captured ~1 Gyear ago or (more likely) it used to be closer in and has been kicked out to its current distance in the last ~1 Gyear. >> What kind of star is it? >It is a mythical star. >> Is it visible through a telescope? >No. The companion star has a mass between approximately .01 and .1 solar masses. Smaller and it would require a very unlikely orbit to produce the postulated effects; larger and it would be too conspicuous an object to have been overlooked so far. This makes it a "brown dwarf", probably too small to have significant fusion going on, and too cold (surface temperature below 2000 degrees) to produce significant visible light, though it should be a fairly bright infrared source. It might, however, be bright enough to look like a very dim red star; as such it would be (at first look) indistinguishable from numerous red dwarfs and particularly from much more distant red giant stars. UC Berkeley is still running a search that will inspect all catalogued faint red stars in the northern hemisphere looking for "parallax" -- evidence that the star is close, because it moves against the background. However, a failure of this search will not rule out a companion, just prove that it is not a) bright in the visible and b) in the northern hemisphere. Note that there is no a priori reason for the companion to lie in the plane of the solar system; it could be anywhere in the sky. The Nemesis hypothesis is indeed "just" a hypothesis, in that there is no direct confirmation. The two predictions above, however, have certainly not been disproved, and there is some evidence in their favor -- some periodicity in the handful of well-dated craters, and some evidence for multiple impacts at the major extinctions, including evidence for _both_ ocean and land impacts at the CT boundary. Currently no other theory accounts as well for periodicity of either extinctions or craters, or for multiple impacts. > >> Was this just a trendy theory that got tossed out after a while? > >Yes. > No, absolutely not. It is a speculative theory, but one which has some support and no contradictory evidence. >> My wife's sixth-grade students want to know... > >Teach them the difference between theory and observation, and you'll do >them a life-long favor. > Agreed. But make sure they neither accept theories as fact _nor_ dismiss them as falsehoods. >-- >Ed Nather >Astronomy Dept, U of Texas @ Austin Jordin Kare Special Projects Group, LLNL -formerly at- U. C. Berkeley/ Lawrence Berkeley Labs. ------------------------------ Date: 19 May 89 12:45:30 GMT From: mcvax!ukc!etive!djm@uunet.uu.net (D Murphy) Subject: Re: Andromeda Strain In article <8905181459.AA03853@crash.cs.umass.edu> ELIOT@cs.umass.edu writes: > > By the way, I do think it is possible that an extraterrestrial bug > could cause problems on earth, although very unlikely. ~rI am thinking > that something couldevolve to live in an incredibly harsh and spartan > extraterrestrial environment by being able to extract energy from > almost any kind of molecule. }iConsider for example, molds and > such. They will grow on any kind of decomposing organic matter. > They are not in any sense host-specific. Now imagine one that grew > much more rapidly in a suitable environment, say inside the lungs. > > Chris Eliot This comment perhaps shouldn't be here - but in support of the above there is a terrestrial equivalent (New Jersey'll hate this, creeping alt.sex into sci.space :-)). I read once that syphillis (and perhaps one or 2 other `venereal' diseases were at one time indigenous to certain parts of Africa where they grew outside the body in warm, moist conditions. Upon being inadvertently taken to Europe they were only able to survive in areas of the body which were 1. Accessible from the outside, 2. Warm and damp and 3. Not full of nasty enzymes which would try to digest the organisms. Murff.... JANET: djm@uk.ac.ed.etive Internet: djm%ed.etive@nsfnet-relay.ac.uk Murff@uk.ac.ed.emas-a Murff%ed.emas-a@nsfnet-relay.ac.uk trinity@uk.ac.ed.cs.tardis trinity%ed.cs.tardis@nsfnet-relay.ac.uk D.J. Murphy *Artificial* intelligence ? Evidently..... ------------------------------ Date: 19 May 89 18:10:53 GMT From: hpfcdc!hpfcdj!myers@hplabs.hp.com (Bob Myers) Subject: Re: citizens in space -- risk silliness >>... If the costs were trivial, >>United Airlines would be offering LEO as a tourist attraction, and you'd just >>be faced with a stack of liability waivers to sign before you got aboard. >It's not that simple any more, in the US in particular. Getting sworn >statements from your passengers that they understand the risks and are >taking them voluntarily will *not* protect you from the lawyers if >something -- anything -- goes wrong. It may provide useful ammunition >for the enormously-expensive court battle, but it won't avert it. Still irrelevant, Henry; I claim that if the costs were trivial, SOMEBODY would be offering a "tourist ride"; the fact that this is not happening means that we cannot yet ignore cost in the "ordinary citizen in space" question, which was my original point. Bob Myers | "Man will occasionally stumble over the truth, but {the known universe} | most of the time he will pick himself up and continue." !hplabs!hpfcla!myers | - Winston Churchill ------------------------------ Date: 20 May 89 16:06:09 GMT From: aramis.rutgers.edu!paul.rutgers.edu!masticol@rutgers.edu (Steve Masticola) Subject: Ballistic parachutes (was: Giotto) Bob Gray writes: > Giotto isn't carrying enough fuel to slow down as it passes > the Earth (You can't just put on the brakes you know :->). Maybe you can put on the brakes. IF Giotto survives, and can be steered to the vicinity of Earth, could it use the upper atmosphere to brake into LEO or permanent orbit, without melting itself in the process? If so, it might be possible to recover nonvolatile comet remnants from the wreckage at a later date. I believe the term for this maneuver is "ballistic parachuting." - Steve (masticol@paul.rutgers.edu) ------------------------------ Date: 21 May 89 08:11:17 GMT From: shelby!Portia!hanauma!joe@eos.arc.nasa.gov (Joe Dellinger) Subject: Re: Andromeda Strain In article <31625@sri-unix.SRI.COM> ELIOT@cs.umass.edu writes: > Now imagine one that grew > much more rapidly in a suitable environment, say inside the lungs. Interesting idea. I think this would pretty much happen with regular Earth bugs, except for our immune system actively preventing it (isn't this what actually kills most AIDS patients, in fact?). So the question is, how specific to Earth-based life are the methods our immune system uses to recognize and zap interlopers? Could we imagine some nasty alien bug which likes warm, moist, carbon-rich environments as energy sources, is not very picky about what it eats, and which our immune system doesn't even see or can't even scratch? (Finally, a posting to sci.space within Henry's nominal field of expertise?!) \ /\ /\ /\/\/\/\/\/\/\.-.-.-.-.......___________ \ / \ / \ /Dept of Geophysics, Stanford University \/\/\.-.-....___ \/ \/ \/Joe Dellinger joe@hanauma.stanford.edu apple!hanauma!joe\/\.-._ ------------------------------ Date: Sun, 21 May 1989 19:03-EDT From: Dale.Amon@H.GP.CS.CMU.EDU Subject: Re: SPACE Digest V9 #432 > In fact, not one person responded to my original posting with an > argument in favor of the manned space program. The answer is that the group is bored silly by this topic. It was beaten to death with a dead heron only a few months ago. If you are truly interested, go back through the last few years of archives of Space Digest. You will find enough discussion to not only put you to sleep, but to put you into a very deep coma. ------------------------------ Date: Sun, 21 May 1989 20:40-EDT From: Dale.Amon@H.GP.CS.CMU.EDU Subject: Re: SPACE Digest V9 #443 > It is not at all clear whether this method would work, though, since > the projectile might just go through without stopping. I have my doubts about this statement. Fusion all occurs at the core, and energy is transported between various layers in convection cells. There are also acoustic waves that generate some of the cell pattern at the surface. A body going through the sun would massively disrupt what is currently a very stable situation. I don't think I would want to be anywhere in the neighborhood when the experiment was tried. I have no idea what would happen. I doubt anyone else does either. ------------------------------ End of SPACE Digest V9 #454 *******************