Date: Sun, 2 May 93 05:34:28 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #509 To: Space Digest Readers Precedence: bulk Space Digest Sun, 2 May 93 Volume 16 : Issue 509 Today's Topics: Deployable Space Dock.. Gamma Ray Bursters. WHere are they. HST Antenna OK? HST Servicing Mission Scheduled for 11 Days (5 msgs) Internet resources moon image in weather sat image Philosophy Quest. How Boldly? Rocket Types Satellite around Pluto Mission? (2 msgs) temperature of the dark sky TRUE "GLOBE", Who makes it? U.S. Government and Technolgy Investment Vandalizing the sky. What planets are habitable 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, 30 Apr 1993 15:41:25 GMT From: Henry Spencer Subject: Deployable Space Dock.. Newsgroups: sci.space In article <1993Apr30.000050.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes: >Why not build a inflatable space dock. If you're doing large-scale satellite servicing, being able to do it in a pressurized hangar makes considerable sense. The question is whether anyone is going to be doing large-scale satellite servicing in the near future, to the point of justifying development of such a thing. >...inflate the dock with a gas (is does not have to be oxygen, just neeeds to >be non-flameble, non-damaging to the satellite and abel to maintain heat)... You'd almost certainly use air. Given that you have to pressurize with *something*, safety considerations strongly suggest making it breathable (even if the servicing crew is using oxygen masks for normal breathing, to avoid needing a ventilation system, it's nice if the hangar atmosphere is breathable in a pinch -- it makes mask functioning much less critical). -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 30 Apr 1993 11:53:45 -0400 From: Pat Subject: Gamma Ray Bursters. WHere are they. Newsgroups: sci.space In article <29APR199311425584@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes: |In article <1rlrpv$5ta@access.digex.net>, prb@access.digex.com (Pat) writes... |>Is this a big enough problem, to create a new area of physics? |>just a little speculative thinking folks. |>pat |Well pat for once I agree with you and I like your first idea that you had. >IT probably is the gamma ray signature of the warp transitions of interstellar >spacecraft! :) Dennis. WE agree a lot , it's just we don't both post when we agree on something. And when we disagree, it tends to be a lot more noticeable.;-) pat ------------------------------ Date: 30 Apr 1993 16:05:24 GMT From: Steve Derry Subject: HST Antenna OK? Newsgroups: sci.space,sci.astro I haven't seen any mention of this in a while, so here goes... When the Hubble Telescope was first deployed, one of its high gain antennas was not able to be moved across its full range of motion. It was suspected that it had been snagged on a cable or something. Operational procedures were modified to work around the problem, and later problems have overshadowed the HGA problem. Is there any plan to look at the affected HGA during the HST repair mission, to determine the cause of its limited range of motion? Is the affected HGA still limited, or is it now capable of full range of motion? -- Steve Derry ------------------------------ Date: Fri, 30 Apr 1993 15:10:54 GMT From: hathaway@stsci.edu Subject: HST Servicing Mission Scheduled for 11 Days Newsgroups: sci.space,sci.space.shuttle,sci.astro In article <1rq3os$64i@access.digex.net>, prb@access.digex.net (Pat) writes: > In article <3t75nhg@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes: > | > | As Herny pointed out, you have to develop the thruster. > |Also, while much lighter, you still have to lift the mass of > |the thruster to orbit, and then the thruster lifts its own > |weight into a higher orbit. And you take up room in the payload >>bay. >> > > a yes, but the improvement in boost orbit to the HST is Significant, I do not understand what you are saying here. What is improved, what is Significant, and what does this have to do with carrying more equipment on a servicing mission? Also, as implied by other posters, why do you need to boost the orbit on this mission anyway? Maybe you have something here, but could you please clarify it for us on the net? > and that means you can then carry EDO packs and enough consumables > so the SHuttle mission can go on long enough to also fix the > array tilt motors, and god knows what else is going to wear out From what I've heard, the motors are fine - it is one of the two sets of electronics that control the motors that needs a fix. The motors and electronics are separate pieces of hardware. I expect to be corrected if I'm wrong on this. > on the HST in the next 9 months. > > pat > ------------------------------ Date: 30 Apr 1993 11:34:31 -0400 From: Pat Subject: HST Servicing Mission Scheduled for 11 Days Newsgroups: sci.space,sci.space.shuttle,sci.astro In article henry@zoo.toronto.edu (Henry Spencer) writes: > >No, the thing is designed to be retrievable, in a pinch. Indeed, this >dictated a rather odd design for the solar arrays, since they had to be >retractable as well as extendable, and may thus have indirectly contributed >to the array-flapping problems. Why not design the solar arrays to be detachable. if the shuttle is going to retunr the HST, what bother are some arrays. just fit them with a quick release. one space walk, or use the second canadarm to remove the arrays. pat ------------------------------ Date: 30 Apr 1993 11:47:04 -0400 From: Pat Subject: HST Servicing Mission Scheduled for 11 Days Newsgroups: sci.space,sci.space.shuttle,sci.astro In article <1993Apr30.101054.1@stsci.edu> hathaway@stsci.edu writes: >In article <1rq3os$64i@access.digex.net>, prb@access.digex.net (Pat) writes: >> In article <3t75nhg@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes: |> | |> | As Herny pointed out, you have to develop the thruster. |> |Also, while much lighter, you still have to lift the mass of |> |the thruster to orbit, and then the thruster lifts its own |> |weight into a higher orbit. And you take up room in the payload |>>bay. |>> |> |> a yes, but the improvement in boost orbit to the HST is Significant, | |I do not understand what you are saying here. What is improved, what |is Significant, and what does this have to do with carrying more |equipment on a servicing mission? Also, as implied by other posters, why |do you need to boost the orbit on this mission anyway? Maybe you have |something here, but could you please clarify it for us on the net? | RIght now the HST sevicing mission is listed as 11 days. before it was listed as 9 days. they just kicked up the number of spacewalks to 5, after simulations indicated that it was not do-able in 4. After all the space walking, they are going to re-boost the HST's orbit. I think right now it's sitting at 180 miles up, they would like 220. I don't know the exact orbit numbers. I know when HST was first flown, it was placed in the Highest possible Shuttle orbit. Now the shuttle can cary a thing called the EDO pallet, or extended duration orbiter pallet. It's mostly LOX/LH for the fuel cells and RCS gear, plus more O2 and canisters for the life support re-breathers. maybe more nitrogen too. THe limit on space-walking is a function of suit supplies (MASS) and Orbiter Duration. In order to perform the re-boost of the HST, the OMS engines will be fired for a long period. Now the shuttle is a heavy thing. THe HST isn't light either. THe amount of OMS fuel needed to fly both up is substantial. a small booster carried up and used to boost HST on it's own will weigh significantly less then the OMS fuel required to Boost both HST and SHUttle, for a given orbital change. From what i understand, the mass margins on the HST missions are tight enough they can't even carry extra Suits or MMU's. Now if they used a small tug, I would bet, just a wild guess, that the savings on amss margin would allow carrying the EDO pallet, extra suits, more consumables, parts for the flaky FGS sensor, parts for the balky solar electronics, and still enough for a double magnum of champagne. or the HST could even get placed into some sort of medium orbit. The reason they want a high orbit, is less antenna pointing, and longer drag life. |> and that means you can then carry EDO packs and enough consumables |> so the SHuttle mission can go on long enough to also fix the |> array tilt motors, and god knows what else is going to wear out | |From what I've heard, the motors are fine - it is one of the two |sets of electronics that control the motors that needs a fix. The |motors and electronics are separate pieces of hardware. I expect |to be corrected if I'm wrong on this. | a Whatever it is, the problem in the tilt array is a big constraint on HST ops. pat ------------------------------ Date: 30 Apr 1993 16:24:51 GMT From: Steve Derry Subject: HST Servicing Mission Scheduled for 11 Days Newsgroups: sci.space,sci.space.shuttle,sci.astro Pat (prb@access.digex.net) wrote: : THe limit on space-walking is a function of suit supplies (MASS) : and Orbiter Duration. : In order to perform the re-boost of the HST, the OMS engines : will be fired for a long period. Now the shuttle is a heavy : thing. THe HST isn't light either. THe amount of OMS fuel : needed to fly both up is substantial. a small booster : carried up and used to boost HST on it's own will weigh significantly : less then the OMS fuel required to Boost both HST and SHUttle, : for a given orbital change. : From what i understand, the mass margins on the HST missions are : tight enough they can't even carry extra Suits or MMU's. : pat I haven't seen any specifics on the HST repair mission, but I can't see why the mass margins are tight. What are they carrying up? Replacement components (WFPC II, COSTAR, gyros, solar panels, and probably a few others), all sorts of tools, EVA equipment, and as much OMS fuel and consumables as they can. This should be lighter than the original HST deployment mission, which achieved the highest altitude for a shuttle mission to date. And HST is now in a lower orbit. Seems like the limiting factors would be crew fatigue and mission complexity. -- Steve Derry ------------------------------ Date: Fri, 30 Apr 1993 15:57:33 GMT From: Henry Spencer Subject: HST Servicing Mission Scheduled for 11 Days Newsgroups: sci.space,sci.space.shuttle,sci.astro In article <1993Apr30.101054.1@stsci.edu> hathaway@stsci.edu writes: >... Also, as implied by other posters, why >do you need to boost the orbit on this mission anyway? ... You don't *need* to, but it's desirable. HST, like all satellites in low Earth orbit, is gradually losing altitude due to air drag. It was deployed in the highest orbit the shuttle could reach, for that reason. It needs occasional reboosting or it will eventually reenter. (It has no propulsion system of its own.) This is an excellent opportunity, given that there may not be another visit for several years. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Fri, 30 Apr 93 15:20:29 BST From: Ata Etemadi Subject: Internet resources Newsgroups: sci.space In article , STK1203@VAX003.STOCKTON.EDU writes: -| I am taking a course entitled "Exploring Science Using Internet". -| For our final project, we are to find a compendium of Internet resources -| dealing with a science-related topic. I chose Astronomy. Anyway, I was -| wondering if anyone out there knew of any interesting resources on Internet -| that provide information on Astronomy, space, NASA, or anything like that. -| -| THANKS! -| -| KEITH MALINOWSKI -| STK1203@VAX003.Stockton.EDU -| P.O. Box 2472 -| Stockton State College -| Pomona, New Jersey 08240 Try doing a keyword search under Gopher using Veronica or accessing a World Wide Web server. Also finger yanoff@csd4.csd.uwm.edu for a list of Internet resources which includes 2-3 sites with Space-specific information. I am sure Ron Baalke will have told you about what is available at JPL etc.. best regards Ata <(|)>. -- | Mail Dr Ata Etemadi, Blackett Laboratory, | | Space and Atmospheric Physics Group, | | Imperial College of Science, Technology, and Medicine, | | Prince Consort Road, London SW7 2BZ, ENGLAND | | Internet/Arpanet/Earn/Bitnet atae@spva.ph.ic.ac.uk or ata@c.mssl.ucl.ac.uk | | Span SPVA::atae or MSSLC:atae | | UUCP/Usenet atae%spva.ph.ic@nsfnet-relay.ac.uk | ------------------------------ Date: Fri, 30 Apr 1993 16:48:44 GMT From: George Wm Turner Subject: moon image in weather sat image Newsgroups: sci.astro,sci.space,sci.geo.meteorology,sci.geo.geology an image of the moon has been caught in a weather satellite images of the earth. it appears in both the 0430-1500UT ir and visual images of the earth. the GIF images can be down loaded from vmd.cso.uiuc.edu and are named CI043015.GIF and CV043015.GIF for the IR and visual images respectively. pretty cool pictures; in the ir it's saturated but in the visual image details on the moon are viewable. the moon is not in the 1400UT images. george wm turner turner@bigbang.astro.indiana.edu ------------------------------ Date: Fri, 30 Apr 1993 13:14:58 GMT From: Doug Loss Subject: Philosophy Quest. How Boldly? Newsgroups: sci.space In article <1993Apr29.162132.28366@hemlock.cray.com> bobo@thejester.cray.com (Bob Kierski) writes: > > >There are a number of Philosophical questions that I would like to ask: > >1) If we encounter a life form during our space exploration, how do we >determine if we should capture it, imprison it, and then discect it? > Analog SF magazine did an article on a similar subject quite a few years ago. The question was, if an alien spacecraft landed in Washington, D.C., what was the proper organization to deal with it: The State Department (alien ambassadors), the Defense Department (alien invaders), the Immigration and Naturalization Service (illegal aliens), the Department of the Interior (new non-human species), etc. It was very much a question of our perception of the aliens, not of anything intrinsic in their nature. The bibliography for the article cited a philosophical paper (the name and author of which I sadly forget; I believe the author was Italian) on what constitutes a legal and/or moral person, i.e., a being entitled to the rights normally accorded to a person. The paper was quite interesting, as I recall. >2) If we encounter a civilization that is suffering economicly, will >we expend resources from earth to help them? > I think you'd have to be very careful here if the answer is yes. The human track record on helping those poor underpriveleged cultures (does underpriveleged mean not having enough priveleges?) is terrible. The usual result is the destruction or radical reorganization of the culture. This may not always be wrong, but that's the way to bet. >3) With all of the deseases we currently have that are deadly and undetectable, >what will be done to ensure that more new deadly deseases aren't brought >back, or that our deseases don't destroy life elsewhere? > >-- >Have a day, > > @ @ > ( ) bobo Doug Loss loss@husky.bloomu.edu ------------------------------ Date: Fri, 30 Apr 1993 15:37:16 GMT From: Henry Spencer Subject: Rocket Types Newsgroups: sci.space In article <1rpv9o$k00@wraith.cs.uow.edu.au> u9152083@wraith.cs.uow.edu.au (Glen Justin Balmer) writes: >It said that in the 60's they developed a rocket that used ions or nuclear >particles for propolsion. >The government however, didn't give them $1billion for the developement... I'd guess this was a garbled report of the NERVA effort to develop a solid-core fission rocket (the most mundane type of nuclear rocket). That was the only advanced-propulsion project that was done on a large enough scale to be likely to attract news attention. It *could* be any number of things -- the description given is awfully vague -- but I'd put a small bet on NERVA. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 30 Apr 1993 14:56:17 GMT From: Rob Unverzagt Subject: Satellite around Pluto Mission? Newsgroups: sci.space In article <1993Apr30.004311.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes: > Being wierd again, so be warned: Being what? Oh, _weird_. OK, I'm warned! > Is there a plan to put a satellite around each planet in the solar system to > keep watch? I help it better to ask questions before I spout an opinion. Keep watch for what? > How about a mission (unmanned) to Pluto to stay in orbit and record things > around and near and on Pluto.. I know it is a strange idea, but why not?? Oh, the several tens (or hundreds) of millions of dollars it would cost to "record things" there. And I'd prefer a manned mission, anyway. > It could do some scanning of not only Pluto, but also of the solar system, > objects near and aaroundpluto, as well as SETI and looking at the galaxy > without having much of the solar system to worry about.. We've already got a pretty good platform to "scan" the solar system, as well as SETI and looking at the galaxy without having much of the solar system to worry about.. Care to guess where it is? Shag -- ---------------------------------------------------------------------- Rob Unverzagt | shag@aerospace.aero.org | Tuesday is soylent green day. unverzagt@courier2.aero.org | ------------------------------ Date: Fri, 30 Apr 1993 15:53:29 GMT From: Henry Spencer Subject: Satellite around Pluto Mission? Newsgroups: sci.space In article <1993Apr30.004311.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes: >Is there a plan to put a satellite around each planet in the solar system to >keep watch? ... There would be some point to doing long-term monitoring of things like particles and fields, not to mention atmospheric phenomena. However, there is no particular plan to establish any sort of monitoring network. To be precise, there is no particular plan, period. This is a large part of the problem. In this context, it's not surprising that unexciting but useful missions like this get short shrift at budget time. The closest approach to any sort of long-term planetary monitoring mission is the occasional chance to piggyback something like this on top of a flashier mission like Galileo or Cassini. >How about a mission (unmanned) to Pluto to stay in orbit and record things >around and near and on Pluto... It is most unlikely that there is much happening on Pluto that would be worth monitoring, and it is a prohibitively difficult mission to fly without new propulsion technology (something the planetary community has firmly resisted being the guinea pigs for). The combined need to arrive at Pluto within a reasonable amount of time, and then kill nearly all of the cruise velocity to settle into an orbit, is beyond what can reasonably be done with current (that is, 1950s-vintage) propulsion. >It could do some scanning of not only Pluto, but also of the solar system, >objects near and aaroundpluto, as well as SETI and looking at the galaxy >without having much of the solar system to worry about.. Most of this can be done just about as well from Earth. The few things that can't be, can be done better from a Voyager-like spacecraft that is *not* constrained by the need to enter orbit around a planet. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Fri, 30 Apr 1993 16:39:59 GMT From: Steve Willner Subject: temperature of the dark sky Newsgroups: sci.astro,sci.space In article <1993Apr28.002214.16544@Princeton.EDU>, richmond@spiff.Princeton.EDU (Stupendous Man) writes: > If that's the case, let me point out that interstellar dust and > molecules provide many instances of things that are, well, not-too-far > from being blackbodies. Many different observations, including IRAS > and COBE, have determined that interstellar dust grain temperatures > can range from 40K to 150K. Interstellar grains are not at all close to blackbodies. The "large" grains have sizes of order 0.1 micron and absorb visible light with fair efficiency. However, at temperatures below 100 K, 90% of the thermal emission will be beyond 22 microns, where radiating efficiency is poor. (A small antenna cannot easily radiate at long wavelengths.) Thus the grains must heat up more in order to radiate the energy they have absorbed. Moreover, the IRAS observations had a maximum wavelength of 100 microns. Grains colder than 30 K will radiate primarily at longer wavelengths, and IRAS would be relatively insensitive to them. In the extreme limit, grains as cold as 5 K will be almost undetectable by any conceivable observation. Worse still, IRAS color temperatures are heavily contaminated by a population of "small" grains. These grains have only perhaps 50 atoms, and when they are hit by a single photon they heat up to temperatures of several hundred or 1000 K. Of course they cool quickly and then stay cold for a while, but _when they are radiating_ the characteristic temperature is several hundred K. Even a small population of these grains can dramatically raise the observed "average" temperature. A model for local infrared emission consistent with COBE data has three components. These represent scattered radiation from Zodiacal dust (color temperature 5500 K), thermal emission from Zodiacal dust (Tc = 280 K), and thermal emission from Galactic dust (Tc=25 K). At the ecliptic poles, the emissivities or dilution factors are respectively 1.9E-13, 4E-8, and 2E-5. The first two are roughly doubled in the ecliptic plane. To find the thermal equilibrium temperature, we add up the dilution factor times the fourth power of temperature for all components, then take the fourth root. In the table below, starlight comes from Allen's number that stellar emission from the whole sky is equivalent to 460 zero mag stars with B-V color of 0.75. No doubt careful work could do much better. (The person who suggested starlight had a dilution factor of E-4 must have been remembering wrong. We would be cooked if that were the case. In any event, the energy density of starlight comes out about the same as that of the microwave background, and I believe that to be correct.) Dilution Temp. DT^4 Microwave background 1 2.7 53 Galactic dust 2E-5 25 8 Zodiacal dust (emission) 6E-8 280 369 Zodiacal dust (scattering) 3E-13 5500 275 Starlight 1E-13 5500 92 ----- 797 The fourth root of 797 is 5.3 K. Outside the Solar system, the result would be 3.5 K. I find these results surprising, especially the importance of Zodiacal dust, but I don't see any serious mistakes. -- Steve Willner Phone 617-495-7123 Bitnet: willner@cfa Cambridge, MA 02138 USA Internet: willner@cfa.harvard.edu member, League for Programming Freedom; contact lpf@uunet.uu.net ------------------------------ Date: Mon, 26 Apr 1993 18:13:37 GMT From: Terry F Figurelle Subject: TRUE "GLOBE", Who makes it? Newsgroups: sci.space In article MJu@zoo.toronto.edu, henry@zoo.toronto.edu (Henry Spencer) writes: >In article bill@xpresso.UUCP (Bill Vance) writes: >>It has been known for quite a while that the earth is actually more pear >>shaped than globular/spherical. Does anyone make a "globe" that is accurate >>as to actual shape, landmass configuration/Long/Lat lines etc.? > >I don't think you're going to be able to see the differences from a sphere >unless they are greatly exaggerated. Even the equatorial bulge is only >about 1 part in 300 -- you'd never notice a 1mm error in a 30cm globe -- >and the other deviations from spherical shape are much smaller. >-- >SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology >between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry I remember a physic prof. who talked about scaling a cue ball to Earth size. Its was significantly less spherical that the Earth! --- Terry F Figurelle Boeing Defense & Space Group email: tff@plato.ds.boeing.com PO BOX 3999, Mail Stop 6J-EA phone: 206-394-3115 fax:206-394-4300 Seattle, WA 98124-2499 -- Terry F Figurelle Boeing Defense & Space Group email: tff@plato.ds.boeing.com PO BOX 3999, Mail Stop 6J-EA phone: 206-394-3115 fax:206-394-4300 Seattle, WA 98124-2499 ------------------------------ Date: Fri, 30 Apr 1993 15:10:33 GMT From: kjenks@gothamcity.jsc.nasa.gov Subject: U.S. Government and Technolgy Investment Newsgroups: sci.space,talk.politics.space People who criticize "big Government" and its projects rarely seem to have a consistent view of the role of Government in science and technology. Basically, the U.S. Government has gotten into the role of supporting research which private industry finds too expensive or too long-term. (Historically, this role for the U.S. Gov't was forced upon it because of socialism in other countries. In order for U.S. industries to compete with government-subsidized foreign competitors, the U.S. Gov't has taken on the role of subisizing big-ticket or long-lead R&D.) As a Republican, I abhor the necessity for our Government to involve itself in technology this way. I believe that market forces should drive technology, and the world would be a better place for it. But the whole world would have to implement this concept simultaneously, or some countries would have subsidized R&D, while others would not. So the U.S. must subsidize because everybody else does. (This sounds a lot like the farm subsidies arguments behind our GATT negotiations, doesn't it?) But this role of Government subsidies is antithetical to cost-effectiveness. The general idea is to spend money on new technology, and thereby maintain and promote our technological culture, despite the forces in the business world (like the dreaded quarterly earnings report) which erode the ability of U.S. industry to invest in new technology. And since our goal is to spend money, it makes little sense to try to save money. Of course, we could always spend our money more wisely, but EVERYBODY disagrees about that the wisdom should be. It's interesting to note that some of our best tools for cost control available in industry today were derived from Government projects. GANTT charts, CP/M, and most of the modern scheduling software comes from DoD projects and their contractors. The construction industry has taken these tools to the core of their businesses; every large construction project now uses these tools. -- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office kjenks@gothamcity.jsc.nasa.gov (713) 483-4368 "A scientist can discover a new star, but he cannot make one. He would have to ask an engineer to do that." -- Gordon L. Glegg, American Engineer, 1969 ------------------------------ Date: 30 Apr 1993 12:24:11 -0400 From: Robert Bunge Subject: Vandalizing the sky. Newsgroups: sci.astro,sci.space In article jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes: >I'm wondering if "vandalize" is the proper word to use in this situation. My >dictionary defines "vandalism" as "the willful or malicious destructuion of >public or private property, especially of anything beautiful or artisitc." I >would agree the sky is beautiful, but not that it is public or private property. It's public because it belongs to everybody. It's vandalism because many people -- power companies -- do maliciously waste light. If they can sell you or your city or your state an unshielded light that wastes 30 to 50 percent of its light, they make more _money_. Never mind that your money is wasted. Never mind that taxpaper's money is wasted. Never mind that the sky is ruined. Bob Bunge Greed is Great - Gordon Grekko ------------------------------ Date: Fri, 30 Apr 1993 15:34:10 GMT From: Henry Spencer Subject: What planets are habitable Newsgroups: sci.space In article <1rpt1v$q5h@hsc.usc.edu> khayash@hsc.usc.edu (Ken Hayashida) writes: >As for human tolerances, the best example of human endurance in terms >of altitude (i.e. low atmospheric pressure and lower oxygen partial pressure) >is in my opinion to the scaling of Mt. Everest without oxygen assistance... >... This is quite a feat of physiological endurance... Indeed so; it's at the extreme limit of what is humanly possible. It is possible only because Mount Everest is at a fairly low latitude: there is a slight equatorial bulge in the atmosphere -- beyond what is induced by the Earth's rotation -- thanks to the overall circulation pattern of the atmosphere (air cools at poles and descends, flowing back to equator where it is warmed and rises), and this helps just enough to make Everest- without-oxygen feasible. Only just feasible, mind you: the guys who did it reported hallucinations and other indications of oxygen starvation, and probably incurred some permanent brain damage. -- SVR4 resembles a high-speed collision | Henry Spencer @ U of Toronto Zoology between SVR3 and SunOS. - Dick Dunn | henry@zoo.toronto.edu utzoo!henry ------------------------------ End of Space Digest Volume 16 : Issue 509 ------------------------------