Date: Sat, 1 Aug 92 05:07:12 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #058 To: Space Digest Readers Precedence: bulk Space Digest Sat, 1 Aug 92 Volume 15 : Issue 058 Today's Topics: A 12 mile tether that generates 5000v? (2 msgs) Calendar and Zodiak (2 msgs) Energiya's role in Space Station assembly ET's, life in space ETs and Radio Months Odds of Life Phobos & Deimos Uncertainty (2 msgs) Russian/French mission to Mir: agreement signed for futur Shuttle launch still thrilled by a manned space shot (3 msgs) UFO's 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: Fri, 31 Jul 1992 19:18:20 GMT From: "Richard A. Schumacher" Subject: A 12 mile tether that generates 5000v? Newsgroups: sci.space In <2182@tymix.Tymnet.COM> filfeit@rael.Tymnet.COM (Fil Feit) writes: [quotes description of voltage induction in a conductor] >it seems that this must operate with about an 80% efficiency to get 5KV >over 15KM. That seems like alot to hope for. Not applicable: efficiency won't come into it unless you try to extract power from this long skinny generator. A static voltage will be created without any worry about efficiency. > And isn't there an inverse >square rule governing magnetic strength? Is this accounted for in that .5 >Gauss figure? More like inverse cubed, since the Earth's field is mostly dipole, but it still doesn't matter much: the shuttle is already 8000 km away from the center of the magnet, so the 15 km length of the tether makes little difference. (8015/8000)**3 = 1.00562 ------------------------------ Date: 31 Jul 92 15:01:01 From: Glenn Berg Subject: A 12 mile tether that generates 5000v? Newsgroups: sci.space In article <2182@tymix.Tymnet.COM> filfeit@rael.Tymnet.COM (Fil Feit) writes: From the numbers I was sent, (copied from Mr. Cage's E-mail): #The Earth has a magnetic field. Around and above the equator, #it is roughly horizontal, going from north to south. Its intensity #is about .5 Gauss, or 5e-5 Tesla. #The Shuttle orbits the earth roughly horizontally, and even more #roughly, from west to east. It moves at about 8000 meters/sec. #A Tesla is a Weber/m^2, and 1 Weber/sec across a conductor induces #1 volt. Each meter of a vertical conductor riding along with the #Shuttle crosses 5e-5 * 8e3 = 0.4 Wb of flux per second, and has #an induced voltage of about 0.4 volts, more or less. 15 kilometers #of conductor would build up 5000 volts between the ends, no problem. it seems that this must operate with about an 80% efficiency to get 5KV over 15KM. That seems like alot to hope for. And isn't there an inverse square rule governing magnetic strength? Is this accounted for in that .5 Gauss figure? Actually, the efficiency is 100%, or better said, irrelevant. I like to view this problem from the perspective of special relativity. For speeds much less than the speed of light, the transformation for electric fields looks like E' = E + v x B where v (a vector) is the velocity of the primed coordinate system in the unprimed coordinate system. In this case, the primed coordinate system is the one that's moving with the tether (and shuttle), and the unprimed coordinate system could be that of an observer on earth. So v is the velocity of the shuttle as seen by the observer on earth. So if E is zero, then E' = v x B. There is no efficiency involved. It is a mathematical statement of fact. The electric field felt along the tether due to its motion is v x B. To the tether, this is a real electric field. To an observer on earth, it is an induced EMF. -- Glenn A. Berg CASS berg@logan.cass.usu.edu Utah State University Phone: (801)-750-2987 UMC 4405 Fax: (801)-750-2992 Logan, UT 84322 ------------------------------ Date: 31 Jul 92 17:54:38 GMT From: Richard Ottolini Subject: Calendar and Zodiak Newsgroups: sci.space Sender: Unocal USENET News Organization: Unocal Corporation Lines: 15 Originator: stgprao@xing Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article <1992Jul31.040116.3371@news.Hawaii.Edu> tholen@galileo.ifa.hawaii.edu (Dave Tholen) writes: >George Hastings writes: > >> To make up the VERY small difference due to precession, as well >> as to adjust for the slowing of the Earth's rotation due to >> tidal drag of the oceans (caused by the moon's gravitation), >> from time to time they declare "leap-seconds" there was one >> this year. > >Yes, leap seconds are used to correct for irregular rotation, but >they are not used to correct for precession. Precession is a major difference. The stars shift by 1200 seconds a year due to precession. ------------------------------ Date: 31 Jul 92 22:29:00 GMT From: seds%cspara.decnet@FEdex.Msfc.Nasa.Gov Subject: Calendar and Zodiak Newsgroups: sci.space In article <1992Jul31.041102.6028@news.Hawaii.Edu>, tholen@galileo.ifa.hawaii.edu (Dave Tholen) writes... >Gary Coffman writes: > >> There wasn't a March 2000 years ago. The calender we use is a modern >> invention of the 17th century. When the Gregorian calendar was rationalized, >> we lost a week, and renters rejoiced and landlords cried. Precession is not >> figured into the calendar. Unless someone rationalizes the calendar again, >> the seasons will precess across the months. The Chinese calendar, and the >> Jewish calendar now have the new year occurring on dates other than Jan 1. >> That's because both calendars are old enough to have precessed a bit. >> Besides, it's midwinter now, in the southern hemisphere. Which one stands >> on it's head? > >The month of March did exist prior to the 17th century, but not in all >calendars. Precession is figured into the calendar. The seasons will >not precess across the months. I'm no expert on the Chinese calendar, >but I believe it is based on the Moon, not the Sun, so a comparison with >a solar calendar isn't entirely appropriate, but I doubt the new year >differs from January 1 because of precession. I don't know all of them and maybe this is not appropriate for sci.space but here is some trivia on our English naming of the Months and Days of the week January------Janus the Roman God of Judgment February-----Don't Know March--------Roman in origing but cant remember why April-------- Same May----------Ancient Celtic name for month of the mayday festival that used the "Maypole" central object of worship. Also see Phalic symbol June---------Roman in origin July---------Julius Ceasar's month August-------Augustus Ceasar's month September----Septimus Severius's month October------Octavian's month (Augustus's real name) November-----? December-----? Days of the Week Sunday-------Sun's day (Babylonian in origin) Monday-------Moon's day (also babylonian) Tuesday------? Wednesday----Wotan's day (norse God Odin's day) Thursday-----Thor's day (Son of Odin's day) Friday-------Freya's day (wife of Odin? day) Saturday-----Saturn's day (named after a car plant in Tennessee) or Saturn's day (Norse or babylonian?) Just a little trivia pursuit for space folks Dennis, University of Alabama in Huntsville ------------------------------ Date: 31 Jul 92 22:46:00 GMT From: seds%cspara.decnet@Fedex.Msfc.Nasa.Gov Subject: Energiya's role in Space Station assembly Newsgroups: sci.space In article <1992Jul31.172421.1732@samba.oit.unc.edu>, cecil@physics.unc.edu (Gerald Cecil) writes... >seds%cspara.decnet@Fedex.Msfc.Nasa.Gov writes... >> The cross plane maneouver from 51 degrees down to 28.5 degrees has an >> enormous penalty in payload. This is why you will NEVER see a Soyuz at >> SSF orbit unless it is on Energia. The payload penalty will drop Energia's >> delivered payload to around 50,000 pounds. I do not know the dynamics and >> this estimate is based on what I have read in generalities regarding that >> Energia could at best only deliver a Soyuz to SS Freedom. Anybody have >> Delta V numbers for such a plane change? > >To change the plane of an orbit of radius r w/ circular orbital velocity >v by angle Da requires > Delta-v = 2v sin(Da/2) [ 1 ] >For 39 <= Da <= 60 degrees this can be reduced by doing the plane change >at a larger radius ra because v decreases w/ radius. However, the energy >required to place the vehicle in the transfer orbit increases w/ radius. >So there is an intermediate radius that minimizes the energy requirements, >given by > ra/r = sin(Da/2) / [ 1 - sin(Da/2) ] >When Da = 39 deg, ra/r = 1, and when Da = 60 deg, ra/r = infinite. >In this case > Delta-v = 2v{ Sqrt[ra/r]*Sqrt[2/(1+ra/r)]*[1+sin(Da/2)/(r/ra)] - 1 } [2] >w/ ra > r. > >For the case of an Energiya launch (51 deg. inclination) to reach Space >Station Freedom (28.5 deg. inclination) Da < 39 deg. so equation [2] offers >no advantage over [1], and from [1] you require a Delta-v = 39% on top of >the initial circular velocity, essentially the same as that required to reach >escape velocity (41%) from radius r! (This explains why the Apollo did all >the maneuvering during the Apollo-Soyuz Test Mission ... the SM engine had >the populsive capability and I believe that the Saturn 1B was launched >at higher inclination than 28.5 degs. The capability was sufficiently >marginal however, that the Apollo had insufficient fuel to reboost >Skylab after the Soyuz rendezvous.) Energiya is capable of placing about >105,000 kg in LEO and about 16,000 kg to escape or approximately to Space >Station Freedom. Soyuz has a mass of about 7,600 kgs. > >All this suggests that for Energiya to play any role in Space Station >assembly, the Station would have to be assembled in a higher inclination >orbit, say 40 degs. >-- >Gerald Cecil 919-962-7169 Dept. Physics & Astronomy >U of North Carolina, Chapel Hill, NC 27599-3255 USA >-- Intelligence is believing only half of what you read; brilliance is > knowing which half. ** Be terse: each line cost the Net $10 ** As the Shuttle has proven many times you can LAUNCH out of KSC at a higher inclination. The shuttle has launched at inclinations of up to 57 degrees. That is what they did on the Apollo-Soyuz Test Project. As you have shown however, the Apollo CSM did not have the capability to do the plane change down to 28.5 degrees, which if I remember right was the inclination of Skylab. Thanks for the good info there Cecil! Dennis, University of Alabama in Huntsville ------------------------------ Date: Fri, 31 Jul 1992 17:43:05 GMT From: Henry Spencer Subject: ET's, life in space Newsgroups: sci.space In article <1992Jul31.134151.42561@cs.cmu.edu> amon@elegabalus.cs.qub.ac.uk writes: >Another point of interest. It has LONG been known that the ribosomes >are from an ENTIRELY separate evolutionary strain. They don't even >use the same genetic code... I think you mean the mitochondria (and chloroplasts, for plants). A ribosome is just a handful of molecules, a protein factory. A mitochondrion really is a semi-independent organism, with its own genetics and almost certainly an independent origin. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Fri, 31 Jul 1992 17:39:58 GMT From: Henry Spencer Subject: ETs and Radio Newsgroups: sci.space In article <1992Jul30.220544.9067@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: >>>Now subtract out all Population II stars, no heavy elements like iron... > >I mentioned iron for two reasons. First, it's necessary for oxygen >transport via the blood. Tell it to the crustaceans, which use copper instead. >Second, and this is opinion, it's needed >for the planet to have a significant magnetic field to redirect energetic >radiation from the planetary surface... The bulk of the radiation shielding on Earth is from the atmosphere, not the magnetic field. Unquestionably the field is useful, but it's far from essential. (Note that life on Earth has survived many field reversals, during which the field is more or less absent temporarily.) >>>and subtract out all multiple star systems, no stable planetary orbits, >>I'm told this doesn't look like as big a problem as was once thought. > >??? Let me put it another way, stable orbits in the liquid water zone. Old opinions about the stability of planetary orbits in multi-star systems appear to have been too pessimistic. It's not that difficult, especially if the stars are fairly widely separated. >>>subtract out all systems that don't have a planet in the liquid water zone, >The potential liquid water zone of a G star like ours is roughly from >near Venus orbit to somewhat beyond Mars orbit given specially designed >planets in the various places. Now on the solar system scale, that's a >small range of distances. Two planets inside it and one a near miss is "small"? Sounds adequate to me. There is no reason to believe that our solar system is unusually heavily populated in its inner regions, and indeed considerable reason to believe that it is fairly typical. Based on what we know now, most any planetary system around a reasonable star should have at least one planet in the liquid-water zone. The major uncertainty is whether that planet will be the right size for its location. The odds of that aren't 100% by any means (Earth hit, Mars missed), but they aren't one in a million either. One in two? Maybe one in ten if you're a pessimist. >... the accretion process, the remelt, the second >cooling, and finally the out gassing of water vapor and methane that >formed the primordial atmosphere took about 1/3 the life of the solar >system to occur. (At least according to popular theories of planetary >formation) Please cite references. My recollection is that the system is dated at 4.5-5 GYr old, and life on Earth is dated back to 4GYr at least. Life -- simple life -- appeared quickly on Earth, probably as soon as it was cool enough. (This is another encouraging sign, although it might have been a fluke.) >The great extinction, due to oxygen liberation, took another >4 billion years, before oxygen based life became dominant. I think we >can safely assume that intelligent life would require the energetics >only possible to oxygen breathers. I concur that you *probably* need a high-energy chemistry such as that of oxygen, and there are no other good bets evident. (The halogens are comparatively rare elements for fairly fundamental reasons, oxygen is quite abundant for the same reasons.) However, again I'd like to see references for the time scale. Animal life based on oxygen has been extant and probably dominant for most of the history of life on Earth, I believe. What took a long time was the transition to vertebrates, not to oxygen. Superfically this doesn't change the line of argument much, since intelligent invertebrates don't seem very likely either. The important difference is that we're now dealing with a transition whose timing doesn't seem to be constrained by fundamentals of physics. >... One of the greatest unknowns >is whether life bearing planets naturally evolve intelligent creatures, >or whether that's a rare accident. We don't have any data to support >either position very well. Agreed. It took a while for vertebrates to become intelligent here. An unusually long while? An unusually short while? Open question. However, note that it happened to some degree on three parallel lines of development: apes, whales, and elephants. You have to really stretch the point to claim that it's inordinately rare. >>>who've thought about the question say that there are perhaps 50 systems >>>in the galaxy that may have life as we know it. >>References, please... >One of Sagan's books quoted this figure... If memory serves, that number was for communicating civilizations at roughly our current level of development, not just for life. Whether this is the total set of interest depends on whether you assume a relatively short lifetime for such civilizations, as Sagan did. More to the point, he assumed that interstellar distances were an impassable barrier, and that communication was the only issue. Wrong. >>The only argument against extraterrestrial life/intelligence that strikes >>*me* as being particularly telling is the Fermi Paradox: if they're out >>there, why didn't they colonize this planet long before we evolved? > >Assume Einstein is right. Interstellar flight takes longer than the >time available since the Universe began to visit all the stars... Fermi unquestionably assumed Einstein was right. Colonizing the galaxy at speeds we should be able to achieve within a century or two takes millions of years, not billions. Intergalactic flight is more problematic, but shouldn't be necessary unless intelligent life is extremely rare. Starflight is expensive, but not especially difficult. >Or, we are the *first* technological civilization to evolve in the galaxy. But, why? Again, unless you cook the books to make intelligent life extremely rare, there should be a reasonable number of them appearing around now, even if you discount the previous generation of stars (which didn't have a lot of heavy metals, but had some -- the Sun is not a second-generation star, more like third or fourth). Possibly we are the very first, but it's not very likely unless the numbers are really small. The way to bet is that at least one of them would have come about, say, 1% faster... which would be enough. >Or, technological civilizations self destruct. With 100% probability? This seems implausible. Once they no longer have all their eggs in one basket, complete self-destruction should be hard. We're close to that stage. To try and shorten this a bit... there are something like fifty proposed explanations for the Fermi Paradox. (I did a series of articles on this a few years ago for the Canadian Space Society newsletter.) Most of them face the same problem: it's hard to make them work 100%, and one lucky escape would have been enough. You can do it with combinations, but it starts to require a very strained argument, making an awful lot of key assumptions with very little evidence. A single convincing explanation would be a lot more satisfying, especially if it treated our own case as reasonably typical rather than as a one-in-a-billion fluke. You can get away with almost anything by asserting that we're a rare exception. Exactly two of the proposed explanations seemed to me to have potential for being satisfactory: Berserkers, and Failure Of Extrapolation. It's hard to make any natural mechanism obliterate 100% of new civilizations, but if you assume intelligent malice backed by high technology, it's not so difficult... although you might have to stipulate robotic intelligence to get constancy of purpose and will over the time frame involved. My own feeling is that Failure Of Extrapolation is more likely, though: there simply are important facts -- about the universe, the development of intelligence, or galactic civilization -- that we don't yet know. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 31 Jul 92 15:28:22 GMT From: Robert Rubinoff Subject: Months Newsgroups: sci.space In article <1992Jul30.202603.260101@cs.cmu.edu> 18084TM@msu.edu (Tom) writes: >I thought the reason was because the Romans added two months: August, after >Augustus ceaser, and July, after Julius Ceaser? Since they were both before >SEPTember, OCTober, etc, the cute numbering system broke down... How could the Romans *add* months? Did they have a ten month year before then? What they did was *rename* two months after Augustus and Julius. (They were previously called something like Quintember and Sextember). March was indeed the first month in Roman times, and in many places until a few centuries ago. In fact, some places started the year on March 25th or other dates that aren't the first of a month. Robert ------------------------------ Date: 31 Jul 92 17:48:21 GMT From: "Paul J. Gravestock" Subject: Odds of Life Newsgroups: sci.space In article dh4j+@andrew.cmu.edu writes: >But wait! We've proven something that can't be proven. And so God >vanishes in a puff of logic (with apologies to D. Adams). > >Ergo, we aren't alive at all! :P Actually we are all figments of our imagination B-) Paul ------------------------------------------------------------------------------ Paul J. Gravestock | email: paulg@griffin.demon.co.uk Hertfordshire | pgravestock@cix.compulink.co.uk England | ------------------------------------------------------------------------------ ------------------------------ Date: Fri, 31 Jul 1992 18:46:05 GMT From: Dave Chaloux Subject: Phobos & Deimos Uncertainty Newsgroups: sci.astro,sci.space Tyler Brown writes: >There appears to be no clear consensus on the meaning of "Deimos"!!! Also, >several posters gave varying translations for "Phobos"!!! >Curiouser and curiouser... All anyone can agree on is that they are named >after a bad emotion... My favorite combo would be "fear and loathing"...;-) I don't know why this should come as any surprise. Words usually have more than one nuance. Look in any dictionary. Still, you find people when learning a new lanquage want one meaning. Having learned a few in my day (English, Italian, French, Greek, and Hebrew) they just haven't worked out like that. One way of judging how well someone knows a language is how well they select the correct nuance from the context. Regards. ------------------------------ Date: Fri, 31 Jul 1992 18:50:08 -0400 From: David O Hunt Subject: Phobos & Deimos Uncertainty Newsgroups: sci.space,sci.astro AS I recall, the discovery of the two moons went like this: Astronomer looks for moons for many nights, doesn't see them. About to give up, and his wife tells him sternly to look again. There they are, and out of awe he names them. Of course, it could also have something to do with the fact that (dredging out old mythology knowledge here) Phobos and Deimos are the Greek names for the sons of Ares, or Mars in the Roman pantheon. Just my 5 cents (inflation). David Hunt - Graduate Slave | My mind is my own. | Towards both a Mechanical Engineering | So are my ideas & opinions. | Palestinian and Carnegie Mellon University | <<>> | Jewish homeland! ============================================================================ Email: dh4j@cmu.edu Working towards my "Piled Higher and Deeper" Democracy is based on the theory that the people know what they want...and they deserve to get it - GOOD AND HARD! ------------------------------ Date: Fri, 31 Jul 1992 18:02:30 +0000 From: "Paul J. Gravestock" Subject: Russian/French mission to Mir: agreement signed for futur Newsgroups: sci.space In article <1992Jul30.203019.16569@cs.sfu.ca> glennc@cs.sfu.ca writes: > > > The Russian/French Soyuz TM-15 mission to the CIS (Commonwealth of >Independent States) Mir space station has begun its research. Aren't the Russians getting about, the 22-28 July Issue of Flight International gives the Shuttle / Mir link up another going over. Apparantly a cosmonaut will fligh on STS-60 / Discovery mission in November 93, which will possibly involve a space walk with a US astronaut. The mission is sceduled to carry the first Spacehab mid-deck augmentation module. The [ US and Russian ] agencies have also agreed to the docking of a shuttle and Mir around 1994-5 ans a five month flight on Mir by a US astronaut doctor. Paul ------------------------------------------------------------------------------ Paul J. Gravestock | email: paulg@griffin.demon.co.uk Hertfordshire, England | pgravestock@cix.compulink.co.uk | /It may be old news, but I just want to talk\ ------------------------------------------------------------------------------ ------------------------------ Date: 31 Jul 92 18:19:48 GMT From: John Roberts Subject: Shuttle launch Newsgroups: sci.space I usually find that if a Shuttle or other spacecraft is to launch late in the morning on a weekday, and I have to go to work, then it's almost impossible to find out the status until late afternoon or early evening - the major networks usually ignore it until the evening news, and radio news stations are erratic. Therefore, for the benefit of those who haven't heard yet and who receive this message quickly: Apparently the Shuttle was successfully launched this morning. (I phoned someone who was watching at his home.) No further details at present. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 31 Jul 92 19:21:03 GMT From: Richard Ottolini Subject: still thrilled by a manned space shot Newsgroups: sci.space I don't know if anyone else feels the same way, but I find the space shuttle missions this summer to be more interesting than the Olymnpics and presidential conventions. I still get a thrill when I see a manned spacecraft and takeoff even though I've been watching them for 30 years. ------------------------------ Date: 31 Jul 92 16:49:38 From: Brian Yamauchi Subject: still thrilled by a manned space shot Newsgroups: sci.space In article <1992Jul31.192103.18668@unocal.com> stgprao@xing.unocal.com (Richard Ottolini) writes: >I don't know if anyone else feels the same way, >but I find the space shuttle missions this summer to be more >interesting than the Olymnpics and presidential conventions. >I still get a thrill when I see a manned spacecraft and takeoff >even though I've been watching them for 30 years. Yeah, I feel the same way (despite my reservations about the shuttle program). On the other hand, it's amazing how blase' the natives here are about these launches... A (paraphrased) conversation from this morning: KSC-area Native: "You know, the shuttle's going up in about ten minutes." Me: "Yeah, I was just about to head outside to watch the launch. Are you coming?" Him: "Nah, I'm in the middle of doing some work..." Oh well... I suppose you get used to anything. -- _______________________________________________________________________________ Brian Yamauchi Robotics Applications Development Boeing Aerospace Operations yamauchi@cs.rochester.edu Kennedy Space Center _______________________________________________________________________________ ------------------------------ Date: 31 Jul 92 20:27:01 GMT From: Mark Bixby Subject: still thrilled by a manned space shot Newsgroups: sci.space You're not the only one who's still thrilled. Every shuttle launch outside of working hours is eagerly watched on CNN by my wife & I. -- Mark Bixby Internet: markb@spock.dis.cccd.edu Coast Community College District 1370 Adams Avenue District Information Services Costa Mesa, CA, USA 92626 Technical Support (714) 432-5064 "You can tune a file system, but you can't tune a fish." - tunefs(1M) ------------------------------ Date: 31 Jul 92 19:38:14 GMT From: Duane P Mantick Subject: UFO's Newsgroups: sci.space bjohnson@casper.cs.uct.ac.za (B Johnson) writes: >It strikes me that either UFO's are non-existent (UFO in the ETI sense) >or the universe is so crowded with inhabited planets as to make earth >uninteresting. >Lets look at it this way. What would you do if you're the captain of >an interggalactic space exploring vessel. You encounter a planet that >plainly exhibits several life forms ( Intelligent or not). >Do you >a) get all excited, jump up and down, and "radio" base for further > instructions. >b) go have a quick squiz, grab a couple of specimans, and bug out. >c) tell all your intergalactic explorer buddies, so they come have > a look. >d) do a detailed survey, and after determining intelligence, try > and make contact. >e) Say "ho-hum another bunch of bi-peds, how boring." >So the qustion is... if life is as rare as everyone would make it >out to be, and UFO's are around, why aren't we the major attraction >in the galactic fairground. You have some good points here, although it might be worthwhile to point out that you are looking at it from the point of view of "human", with all the self-biases that this suggests. While it seems fairly obvious that the vast majority of UFO reports are pure bullshit so far as any link to ETI is concerned, there remains a body of reports that cannot be explained away by conventional means. One could make the assumption that some percent of these reports suggest "visitation", at least for the purpose of this discussion. Why aren't WE the major attraction? I think that's really fairly simple. If the "visitors" are advanced enough to be capable of travel TO earth and back FROM earth to wherever they might reside, it suggests a level of technology considerably more advanced than ours. Thus, from the technology standpoint, we probably have absolutely NOTHING that they would be interested in. We have been here for umpteen gazillion years as a planet and for (apparently) quite a while as humans of some sort. There has been plenty of time for such an advanced civilization to learn plenty about us - while our means for really reporting, recording and analyzing THEM in any *practical* way is only a few hundred years old, if that much. Given the assumption of a radically higher technology, their ability to hide from us makes our current high-tech "stealth" technology look bozoic by comparison. If the assumed visitors would prefer not to interfere and to remain hidden, I think it would be fairly presumptuous of us to assume that we'd always know they were there. Why should they visit at all? That's kind of a tough question to answer without resorting to the aforementioned human concepts of thought. Perhaps they are as naturally curious as we are. Perhaps they are interested in watching our technological develpoment like WE might watch football (hmmm....wonder if they take bets on us? 1945 - will it blow up over Hiroshima or not.... OOPS, you lose! Geez, these humans are murdering swine! :-) ) (of course, to borrow from another thread - if they were like Klingons, they'd have been pleased by the use of the Abombs in 1945...) As far as making contact is concerned, why? Think about it. If they are such an advanced race with presumably advanced societies, why the heck do they want primitive savages like humans dogging them? To an advanced civilization, we probably come off looking like third-rate kamikazes. There have been many speculations thrown around that we attract "visitors" with our radio waves and power emanations and so forth. Until we actually ever got a chance to talk to one of said visitors, who would know? Duane ------------------------------ End of Space Digest Volume 15 : Issue 058 ------------------------------