Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Thu, 17 May 90 02:13:18 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 17 May 90 02:12:48 -0400 (EDT) Subject: SPACE Digest V11 #413 SPACE Digest Volume 11 : Issue 413 Today's Topics: Re: Spectroscopy on the HST Re: SPACE Digest V11 #396 Galileo Update - 05/16/90 Terraforming Venus Re: Terraforming Venus (was: Manned mission to Venus) Measurement in space What was NOTSNIK ??? ---------------------------------------------------------------------- Date: 16 May 90 15:26:35 GMT From: usc!elroy.jpl.nasa.gov!jato!mars!baalke@ucsd.edu (Ron Baalke) Subject: Re: Spectroscopy on the HST In article <1990May15.221501.14059@stretch.cs.mun.ca> chris2@stretch.cs.mun.ca (Chris Paulse) writes: > >I've seen mentioned in the bulletins regarding the Hubble Space >Telescope the Goddard High Resolution Spectrograph. Would anyone be >so kind as to fill me in on what this apparatus is (will be) >capable of doing? > The Goddard High Resolution Spectrograph is designed to observe ultraviolet radiation from objects, and will tell the composition, temperature and density of stellar objects and vast gas clouds thoughout the universe. ------------------------------ ReSent-Message-ID: Resent-Date: Wed, 16 May 90 13:45:05 EDT Resent-From: Harold Pritchett Resent-To: Space discussion group Date: Wed, 16 May 90 03:43 CST From: Kevin 'Charlie' Brown Subject: Re: SPACE Digest V11 #396 Original_To: JNET%"space@tcsvm" Original_Cc: CSCI31F7 This message was originally submitted by CSCI31F7@UHCL2 to the SPACE list at TCSVM. If you simply forward it back to the list, it will be distributed with the paragraph you are now reading being automatically removed. If you edit the contributions you receive into a digest, you will need to remove this paragraph before mailing the result to the list. Finally, if you need more information from the author of this message, you should be able to do so by simply replying to this note. ----------------- Message requiring your approval (172 lines) ----------------- In message <9005141459.AA01107@alw.nih.gov>, AZM@CU.NIH.GOV writes: >> >> > What are the odds of two civilizations existing at the same time? >> >Earth is at least 3 billion years old, and we have been using radio for >> >maybe 100 years. Assuming no change in the world population trends we >> >will no longer have resources for space exploration in another 100 >> >years. That leaves a very small window for an intelligent race to >> >discover us. >> >How fortunate for them. Sorry, but if I were a spacefaring race, *I* wouldn't be afraid of a planet-bound civilization when all I had to do was drop a few rocks on them if they became a threat... >> This overly pessimistic and has many flaws. First, I thought one of the >> reasons for developing space is to expand are supply of resources. In >> our solor system there are huge supplies of metals, energy, etc., etc. >> Second, Assuming no change in world population trends may be flawed. The >> US for example in the past century has went from large population growth >> to negative population growth (Our small population growth is from >> immigration). Likewise most other 'Developed nations' have. It is only >> third world nations that have a population boom. >> >The current, and forever into the future trend in world population is up. >Fortunately, this too is a self-limiting process. Rampant disease, grind- >ing poverty, and starvation will reduce the total number of humans on >Earth. This assumes that humans are unable to control their ability to reproduce, which has been demonstrated NOT to be the case. Already, there are several countries in Europe that have achieved zero population growth (Switzerland, Italy, and Greece to name a few) WITHOUT disease, poverty, and starvation being the primary driving forces. As technology spreads and increases, the population will stabilize because in a technological society, children are a hinderance, not an asset. >> Lets treat Earth as a typical planet. It seems that civilizations will >> becoming into space technology just as many other problems are starting >> to become acute. The question is what is the probability that a >> civilization will adress these problems and solve them before it is too >> late. (avoid blowing themselves up, destroying the enviroment, and >> overpopulating themselves). I personally would say the probability of >> this is at least 1 in 10 civilizations would make it and extend their >> window well beyond the 100 years you give them. >> >After all, look at how well we're doing at it. If Earth is taken as a >"typical planet," then not only is the human race on its way to quiet >oblivion, but the entire universe, and all the beings in it are as well. It is possible that mankind is on the road to self-destruction, but recent events seem to indicate otherwise. Firstly, if mankind were so incredibly warlike, then we'd probably all be dead by now. We've had nuclear weapons for over 40 years and not a SINGLE ONE has EVER been used since the end of World War II (except in tests). And after World War II, *all* the wars have been small-scale, limited to relatively small regions of the planet that have high poverty levels and low education levels. Korea, VietNam, El Salvador, Iran, Iraq, etc. are all small countries with relatively uneducated populations (Korea being the exception in modern days, but perhaps not during the Korean War. I don't have any data on this). Secondly, most people have a built-in survival instinct that is linked with the conscious mind, i.e. they won't do something if they know consciously that it will kill them, unless they have a legitimate reason (e.g., to save another life). They can fight knowing that they will die, but they must have a conscious, legitimate (to them) reason for doing so. If you were the leader of a nation and you had the choice of pushing the button, knowing that you and most of the rest of your nation would die as a result, would YOU press the button? I know I wouldn't. Nor would any other sane person. Call me a wimp if you like, but a human race under oppressive conditions is better than no human race at all... Which leaves insane leaders. Fortunately, the world (more specifically, the western world) has had experience with such leaders, most notably Hitler. The Germans TO THIS DAY are quite upset about what Hitler did. It'll be a long time before Hitler is forgotten. The population of most countries will probably try to avoid putting into power someone like Hitler again if they can help it. Yes, it's certainly possible that another leader like Hitler will rise to power in a relatively powerful, technologically adept country, but it's not likely any time in the near future. The destruction of the environment is another matter. There ARE people working on the problem, so it becomes a question of whether or not a timely solution will come about. The jury's still out on that, so don't jump to any conclusions. >> I think the real question on E.T.'s is why don't they want to be seen. >> >Now, why wouldn't a race of extraterrestrials want to be seen by us? >Let's see if we can analyze that question. > >If you are on a camping trip in the wilderness, protected by a flimsy >nylon backpacking tent, and you discover,just around nightfall, that >you are directly in the path of a hungry, savage, salivating, snarling >pack of large, ferocious wolves, you do absolutely everything within >your power to render your presence, and the visibility of your pro- >tective shelter, and any possible odors, aromas, or fragrances that >you might be producing, and any and all possible sources of light >alien to the environment, and every single, possible sound however >minute, invisible, and then cringe in fear through the night hoping >that you will not be discovered, and the wolf pack will pass you by. > >That would seem to explain the aliens reluctance to encounter humans. This assumes that the ETs know the specifics about the human race. For that to be true, they must either (a) be within 40 light years, or (b) be a spacefaring civilization with ships that are within 40 light years (or have visited our system before we had widespread use of radio). It's difficult to say which is more likely, but my money's on the spacefaring civilization, mainly because 40 light years is pitifully, incredibly small compared to the size of the galaxy. So we have this spacefaring civilization. You claim that they're afraid of us because we're so ferocious, right? Well... Item 1 : In any system where mutation and natural selection are the basis for evolution of a species, competition for resources will inevitably result. This competition results in aggressive tendencies, since under those conditions aggression is a beneficial survival trait. So if the spacefaring civilization evolved (which seems to me to be the most likely case), then they, too, will be aggressive in nature unless they've managed to breed that aggression out of themselves. I don't know of any other method besides mutation and natural selection that would cause the spontaneous rise of intelligent life ("creation" is out because the use of a supernatural deity is a catch-all explanation. It's too easy an answer). Item 2 : They're a spacefaring civilization. We're not. How can we possibly pose a threat to them under these conditions? We can't even leave our own earth-moon system in a manned spacecraft yet! They could attack at will from a distance and we wouldn't be able to do anything about it. Item 3 : If they've studied us the way you imply they must have, then they would also know that the human race tends to expand its influence whenever possible. When we develop manned interplanetary travel, we *will* colonize the rest of the solar system. When we develop manned interstellar travel, we *will* colonize other star systems. This is simply human nature (the result of evolution. The wider you spread your genes, the higher the likelihood that your genes will survive down through the generations). Now, if we are such a nasty, dangerous race, and so obviously a threat to these aliens, then the logical thing for them to do would be to exterminate us. This is REAL easy to do. You just drop a big rock on earth from way out in space. In fact, the aliens could do this in such a way that it looks like an accident of nature. A small change in the orbit of one of the larger comets out there in the Oort cloud (so THAT's what comet Austin is...they missed! :-) ... If you say they have something against exterminating other races, then I refer you to item 1 with the addition that though they may have bred out their natural aggressive tendencies, they will NOT have bred out their survival instinct, and clearly this is a matter of survival, right?... So now that we've established all that, it's time for a more realistic analogy... You still remain you, but the pack of hungry wolves now becomes a nest of fire ants located next to your house. You know the nest exists, but the ants in the nest don't know you exist. Do you flee in terror, abandoning your house and everything in it? Do you hide in your house, hoping the nasty fire ants won't come along and eat you? No. What you'll do is poison the nest, killing most if not all of the fire ants. Problem solved. > Derd Valpar > aka Marlen > AZM@NIHCU Kevin Brown CSCI31F7@UHCL2 csci31f7@cl.uh.edu ------------------------------ Date: 16 May 90 20:53:31 GMT From: swrinde!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Galileo Update - 05/16/90 GALILEO MISSION STATUS May 16, 1990 The spacecraft is about 97 million miles from Earth, giving a round-trip communications time of 17 minutes 23 seconds. It is moving in solar orbit at just over 64,500 mph, and has gone almost 372 million miles since launch. The trajectory-correction maneuver was carried out Friday and Saturday without any surprises. Two maneuver portions totalling 2920 pulses from the lateral thrusters were designed by the Galileo flight team, transmitted by the Deep Space Network, and executed by the spacecraft as the flight team monitored the activities. The result was a velocity change of about 11 meters per second (25 mph), bringing the trajectory closer to the desired conditions for the Earth gravity assist in December. Four more small maneuvers are scheduled over the next several months to further refine the trajectory. After the maneuver, Galileo returned to its regular cruise routines, keeping sun-pointed and updating its star maps, testing and calibrating various sensors, and making scientific measurements of the interplanetary medium. _ _____ _ | | | __ \ | | Ron Baalke | baalke@mars.jpl.nasa.gov | | | |__) | | | Jet Propulsion Lab | baalke@jems.jpl.nasa.gov ___| | | ___/ | |___ M/S 301-355 | |_____| |_| |_____| Pasadena, CA 91109 | ------------------------------ Date: 16 May 90 22:36:00 GMT From: cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!rpi!rpitsmts!forumexp@tut.cis.ohio-state.edu (Commander Krugannal) Subject: Terraforming Venus I've been meaning to reply to the comment that glass is an excellent infrared barrier. The glass in a stove door is used as an example. Hmmm, I like the idea, perhaps I'll take out all that insulation in my walls and replace it with glass! It'll keep all my heat in and I'll have a great view! Umm, in a word NO! Think about it next time, perhaps its the space or vacumn between the pieces of glass in your stove window that keeps the heat in. Or better yet, take a look at a thermos bottle someday. Perhaps you were thinking of UV radiation? Greg_d._Moore@mts.rpi.edu ------------------------------ Date: 16 May 90 22:32:03 GMT From: swrinde!zaphod.mps.ohio-state.edu!uwm.edu!ogicse!zephyr.ens.tek.com!wrgate!mrloog!dant@ucsd.edu (Dan Tilque) Subject: Re: Terraforming Venus (was: Manned mission to Venus) msdos@calvin.cs.mcgill.ca (Mark SOKOLOWSKI) writes: > The only thing I would like to >add to the discussion here is that it is extremely dangerous to try to >send comets on this planet (of Love... :-) ), for many of this stuff can >reach the Earth, and the kinetic energy contained brought in by such a >meteorite when it crashes at 12 to 100 km per second is sufficient to >vaporize it hundreds of times (remember what happened in Siberia in 1908, >was there really some kind of cooling down?). In other words we will >WARM UP Venus instead of cooling it. True the energy from the comet will heat the atmosphere a little, but the dust from the impact should cause global cooling. However, we will definitely do in any Venusian dinosaurs (dinosaurs just don't adapt well to celetial impacts). The Tunguska event is probably not a good example to use: it did not impact the Earth and didn't toss up any dust. However, 10 km sized comet should definitely hit dirt. >And beside, I don't see we should >disfigurate the venusian landscapes with craters. For God's sake, >ALL the solid objects in our solar system (except Venus and Earth) are >SURSATURATED with those boring, destructive round circles, so please, >DON'T DESTROY THE BEAUTIE OF VENUS!!!!! The main reason Earth's and Venus' landscape aren't dominated by craters is weathering. Adding water would increase the rate of weathering on Venus. The craters will be only temporary. --- Dan Tilque -- dant@mrloog.WR.TEK.COM ------------------------------ Date: 17 May 90 00:02:47 GMT From: amelia!wilbur.nas.nasa.gov!eugene@ames.arc.nasa.gov (Eugene N. Miya) Subject: Measurement in space Some one asked about this: | CONSUMABLE STATUS AS OF 5/15/90 | | P R O P E L L A N T S T A T U S P O W E R | | Consumption | One Week Propellant Remaining Output Margin | Spacecraft (Gm) (Kg) Watts Watts | | Voyager 1 4 36.5 + 2.0 370 59 | Voyager 2 4 39.6 + 2.0 374 66 ^ I wasn't very concern, but over the weekend, the "background process" sync'ed, and I don't think anyone answered this. Doesn't look familiar? All you computer people without a background in engineering or other physical science? Sad. The problem is the person who typed this in didn't have a symbol for this on his keyboard, the limitations of ASCII. It's a tolerance, a plus/or/minus sign. Too much discrete work? Not enough uncertainly, no interval arithmetic, etc.? Welcome to the real world. 8) Also, if you look at some of the NASA HQ postings you will find a person who consistently types an 'l' and 'ell' for a '1' 'one.' You might try reading that line on various screens and see how close your ones and ell's look. --e. nobuo miya, NASA Ames Research Center, eugene@orville.nas.nasa.gov {uunet,mailrus,other gateways}!ames!eugene ------------------------------ Date: Wed, 16 May 90 15:47:32 +0200 From: mpirbn!p515dfi@relay.EU.net (Daniel Fischer) Subject: What was NOTSNIK ??? Cc: p515dfi@unido.informatik.uni-dortmund.de In Av'Leak May 7, 1990, p.108 Greg Stanley writes on the PEGASUS launcher: ] 30 years ago, the Navy at China Lake was responding to the Sputnik success ] with just such a concept, the NOTSNIK. The then-Naval Ordnance Test Station ] (now the Naval Weapons Center) developed and tested a satellite-carrying ] rocket that was launched from an aircraft. Is that true? Did it ever work? Why wasn't this way of launching satellites followed on? I've heard from German aerospace experts that a thing like Pegasus wasn't possible until recently because the aerodynamics of the first part of the flight required modern avionics and computers. But 30 years ago??? +- p515dfi@mpifr-bonn.mpg.de --- Daniel Fischer --- p515dfi@mpifr-bonn.mpg.de -+ | Max-Planck-Institut f. Radioastronomie, Auf dem Huegel 69, D-5300 Bonn 1,FRG | +----- Enjoy the Universe - it's the only one you're likely to experience -----+ ------------------------------ End of SPACE Digest V11 #413 *******************