Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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 ; Sun, 27 Jan 91 02:36:38 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 27 Jan 91 02:36:33 -0500 (EST) Subject: SPACE Digest V13 #081 SPACE Digest Volume 13 : Issue 81 Today's Topics: Re: space news from Dec 17 AW&ST Magellan article trace contaminants Re: 2 dimensional objects Re: What is cosmological constant? Re: Salyut 7 picks up extra term New ESA technical standards documants Re: What is cosmological constant? Availability of the Ames SPACE archives Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 24 Jan 91 17:11:34 GMT From: usc!elroy.jpl.nasa.gov!freedom!cornutt@ucsd.edu (David Cornutt) Subject: Re: space news from Dec 17 AW&ST aws@ITI.ORG ("Allen W. Sherzer") writes: >Had NASA been up front with the risks and run a better operation the >Chalanger disaster PR fallout wouldn't have been that bad. After all, >Apollo 1 didn't come close to killing Apollo. Yes, it did. At the time, there were a number of calls in Congress to kill the program; the speeches sounded almost exactly like what we hear today ("we need to spend money here on Earth instead of throwing it away in space", etc.). The program was more or less shut down for about two years. Only a renewed Cold-War threat of the evil Russkies (:-) getting ahead of us saved it. There are folks down at the Cape who still cringe at the memory of the months following Apollo 1 -- not only because of the horror of the accident, but because every one of them was made to feel personally responsible for it. They were used as national whipping boys, just like after Challenger. -- David Cornutt, New Technology Inc., Huntsville, AL (205) 461-6457 (cornutt@freedom.msfc.nasa.gov; some insane route applies) "The opinions expressed herein are not necessarily those of my employer, not necessarily mine, and probably not necessary." ------------------------------ Date: 24 Jan 91 20:01:24 GMT From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Magellan article Associated Press -- 1/24/91 "Magellan Venus" By Lee Siegel "Volcanic bulges that resemble giant spiders provide more evidence that Venus' landscape is shaped by huge blobs of molten rock rising from inside the planet, say Magellan spacecraft scientists." The AP Los Angeles-based science writer says the bulges, some more than 100 miles wide, support the theory that Venus' terrain is being sculpted by "hot spot tectonics" or "blob tectonics." The story says a similar process created the Hawaiian chain of islands but the dominant geologic process on Earth is plate tectonics. The writer says the Venus scientists are calling the features "arachnoids" because of their resemblance to spiders - a class of animal called arachnids. The story cites one Venus scientist, Ellen Stofan, who suggests that the arachnoids may just be the early stages of what might turn out to be much larger bulges later. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 25 Jan 91 00:06:12 GMT From: EARTH.ARC.NASA.GOV!FINN@ames.arc.nasa.gov (FINN) Subject: trace contaminants Are you doing or planning research *related* to removal, generation, or detection of TRACE COMPONENTS or CONTAMINANTS in air or water? [Examples: removal by adsorption, removal by reactive plasma, generation by algae, generation by offgassing, etc.] If so, I would like to hear from you. I am beginning studies of trace contaminant control in near- closed-loop air and water systems for long-duration manned space missions, and would like to learn what others are doing in related areas. Responses to this letter will assist me in forming a references database, and may provide a starting point for some dialogue/discussion concerning various aspects of trace contaminant control: issues, theories, experiments, innovations, technologies, etc. Electronic or postal mail responses are fine. Brief summaries and short bibliographies are welcome, as are any comments or suggestions. Please pass this letter on to anyone who might be interested but may not otherwise see it. Thank you for your interest. Dr. John E. Finn Advanced Life Support (Regenerative Systems) NASA Ames Research Center M/S 239-11 Moffett Field, CA 94035 finn@earth.arc.nasa.gov P.S.: if you are sending e-mail and the message is not accepted here, please either try again later or send a letter. ------------------------------ Date: 25 Jan 91 07:20:58 GMT From: munnari.oz.au!brolga!covax.commerce.uq.oz.au!bellamy@uunet.uu.net Subject: Re: 2 dimensional objects In article <1730002@hpsad.HP.COM>, erik@hpsad.HP.COM (Erik Kilk) writes: > > I remember Carl Sagan's TV series on the PBC devoted a segment on such > flat people. I can't remember the series name, but it might have been > "Universe." He animated flat people as disks and their homes had just > walls (drawn as lines like in a set of house plans). I think you are referring to the 13 Part series "Cosmos". There was also a book of the same name summarising the series. Very good, but then I'm also a member of the Planetary Society :-) To give the correct credit, I think much of his analogy was drawn from another author (who I can remenber). 'Flatland' seems to come to mind could have been "Flatland : a romance of many dimensions" by Edwin Abbott. My copy of Cosmos is at home. [...deleted] > > I believe all this was to suggest that our 3rd dimension is to the flat > people as a 4th dimension might be to us! Yes, the discussion (from memory) was about 4D space-time. He also showed what the shadow (?) of a 4D 'cube' was like. -- David E. Bellamy Email: bellamy@covax.commerce.uq.oz.au Dept. Commerce, University of Queensland, St. Lucia, AUSTRALIA ------------------------------ Date: 20 Jan 91 09:39:45 GMT From: jarthur!nntp-server.caltech.edu!brun@uunet.uu.net (Todd A. Brun) Subject: Re: What is cosmological constant? In article <5113@disk.UUCP> joefish@disk.UUCP (joefish) writes: > It is difficult for me to understand why Einstein's Cosmological >constant is discussed other than in the interest of the history of >the General Theory of Relativity. > When Einstein introduced it, it was assumed that our galaxy >represented the entire universe, and to be stable, a finite universe >needed the constant. > The type of universe could only have been steady state at the >time, so Einstein did not regret the choice, he merely acknowledged >that if he had known that there were countless galaxies and they >were apparently receding, he would never suggested (or considered) >his cosmological constant. > There is no reason to consider applying his constant at >the present time, but it is useful to remember that the Big Bang >was never thought of until Hubble's discoveries in the 20's and >30's. > Reportedly, Einstein called the cosmological constant "the biggest blunder of my life". However, it is a mistake to dismiss it as only an historical footnote. I'm not an astrophysicist, but they hang out right down the hall from me; and most of them believe that a non-zero cosmological constant is quite plausible, and least at one time. One of them even went so far as to say that "most" cosmologists believe that at one time the cosmological constant was non-zero. Einstein originally invoked the cosmological constant to insure a steady-state universe. This is almost certainly incorrect. But nowadays cosmologists invoke it for the opposite reason -- to explain a tremendously accelerated rate of expansion in the early universe. One of the most successful groups of cosmological theories (but more on that in a second) are the so-called inflationary models. To simplify (since I don't know the details myself), they posit that at one time the universe was in a rapidly-expanding 'inflationary' state, which caused it to expand enormously in a very short time. As there isn't any known reason why this should happen, it is common to invoke a non-zero cosmological constant in the early universe. Why bother to do this? Because, until recently anyway, the inflationary models were the most successful at explaining what we actually see. Nowadays, almost all cosmological models are in very bad shape, being attacked from both ends. On the one had, recent discoveries of very large scale structure in the universe (the 'Great Wall' and 'Great Voids') has made it clear that the present universe is much more inhomogenous that was originally though; on the other hand, measurements of the cosmic background radiation by COBE have made it clear the early universe was very much more homogenous than originally thought. Under this twin strain, about 90% (it may be more by now) of all cosmological models have quietly expired. If COBE manages to push its accuracy to about 1 part in 10^7, it will pretty much have scotched the lot. Anyway, if the cosmological constant was at one time non-zero, the real puzzle is why the heck it's so small now. Having a non-zero cosmological constant is essentially the same as saying that completely empty spacetime isn't flat, which would imply that special relativity isn't actually right. Since, as has been often pointed out in this august newsgroup, SR is the most well-tested physical theory of all time, the corrections due to the constant must be truly minute. Considering the shakiness of all these models in the light of current experiments, your guess is probably as good as anyone else's. ------------------------------ Date: Mon, 21 Jan 91 08:36:52 PST From: greer%utdssa.dnet%utaivc@utspan.span.nasa.gov X-Vmsmail-To: UTADNX::UTSPAN::AMES::"space+@andrew.cmu.edu" Subject: Re: Salyut 7 picks up extra term In SPACE Digest V13 #067, isis!scicom!wats@uunet.uu.net (Bruce Watson) writes: >Salyut 7 has picked up the extra term in the polynomial that >modifies the mean motion. The period as of day 91 09.31 is >89.93 minutes with a mean height of 271 kms. ^^^ The plural of km is km. _____________ Dale M. Greer, whose opinions are not to be confused with those of the Center for Space Sciences, U.T. at Dallas, UTSPAN::UTADNX::UTDSSA::GREER "I will continue to use my boat." -- George Bush ------------------------------ Date: Tue, 22 Jan 91 15:47:31 CET From: Hermann Schneider Subject: New ESA technical standards documants For interested people: ======================================================================== PUBLICATION OF NEW SPACE DATA COMMUNICATIONS STANDARDS The two following Space Data Communications Standards are now available in their final PSS format: W "Telemetry Channel Coding Standard",ESA PSS-04-103,Issue 1,Sept.1989 W "Ranging Standard",ESA PSS-04-104,Issue 1 of Volume 1:"Direct Ground to Spacecraft Ranging",April 1990 Copies can be obtained from the ESA Publications Division (IP) by contacting Mr.F. De Zwaan via PROFS. IP is also at your disposal to provide copies of the two already published Space Data Communications standards: -------------------------------------- W "Radio Frequency and Modulation Standard",ESA PSS-04-105 W "Packet Telemetry Standard",ESA PSS-04-106 Finally, one other PSS document in the same series is expected to be published by IP during February 1990 : W "Packet Telecommand Standard",ESA PSS-04-107,Issue 1,June 1990 Until then, copies of this document in a provisional format can be obtained from: Mr.Lelann (ESTEC,WGO*,Ext.3720), or Mr.D.Rouat (ESTEC,WDP,Ext.3678) in the absence of Mr.Lelann. Regards Hermann Schneider (Communication Systems Programer) ESOC (European Space Agency's Operations Centre) ------------------------------ Date: 23 Jan 91 15:30:01 GMT From: mcsun!unido!mpirbn!p515dfi@uunet.uu.net (Daniel Fischer) Subject: Re: What is cosmological constant? In article <5113@disk.UUCP> joefish@disk.UUCP (joefish) writes: > It is difficult for me to understand why Einstein's Cosmological >constant is discussed other than in the interest of the history of >the General Theory of Relativity. [...] > There is no reason to consider applying his constant at >the present time... > >Joe Fischer joefish@disk.UUCP ^^^^^^^ Dan Fischer just can't resist posting what I heard in a lecture here just one hour ago: the Cosmological Constant does exist, it is a fundamental constant of nature like Planck's or gravity's, and its most likely value is: 1/(36*10^18) 1/(lightyears)^2. The age of the uiverse is (30+/-5)*10^9 years. Any questions? :-) Well, let me give just a bit more background (sorry, have still to read 638 articles in alt.desert-storm and a mailbox full of flames... :-<): What Prof. W. Priester just presented is a cosmological model that seems to be capable of explaining virtually all cosmological problems of 1991: o The existence of the cosmic large-scale structure that just killed the famous Standard CDM Model (see NATURE Jan. 3 and SCIENCE Jan. 18, 1991), o Why even the most distant quasars (with z>4.5) still show so many emission lines of heavy elements that hint at a high age>>10^9 years, o And why a Hubble Constant around 90 km/s/Mpc is consistent with an age of the universe >=18*10^9 years. All one has to do is setting the Cosmological Constant, a genuine constant of integration in Einstein's field equations (giving the inherent curvature of space-time) not canonically = zero as it is usual, but treating it as a free parameter that has to be determined from observations. And what you get is a universe that for the first 20*10^9 years expands very slowly, providing ample time for the formation of large-scale structure ('bubbles & voids') as well as quasar formation (when the age is already around 10^10 years). Later the expansion speeds up and has now reached almost the final value. ------------------------------ Date: 24 Jan 91 06:48:34 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Availability of the Ames SPACE archives I'm pleased to announce that the SPACE archives, located on ames.arc.nasa.gov are once again available via e-mail service. To access the archives, send a letter to archive-server@ames.arc.nasa.gov (or ames!archive-server). In the subject of your letter (or in the body), use commands like: send SPACE Index send SPACE SHUTTLE/ss01.23.91. The capitalization of the subdirectory names is important. All are in caps. The following is a list of the subdirectories that are currently available: APOLLO GIOTTO MANIFEST PRESS.KIT ULYSSES ASTRO HEADLINE.NEWS MARS.ROVER PRESS.RELEASE VICAR BBXRT HST MCSR PROGRAMS VOYAGER COBE HUT MISC RADIO WEATHER CONTRACT IMDISP NTE SHUTTLE WUPPE CRAF OSR SPACE.CLASSROOM FRR PAYLOAD.STATUS SPACELINK GALILEO LAUNCH.ADVISORY PEGASUS GIF MAGELLAN PIONEER UIT The GIF directory contains files in GIF format. A few have been uuencoded so that they be mailed, but unfortunately the majority will not survive mailing. This will be rectified in the future. The VICAR directory has two Magellan images in VICAR format. A PC program capable of displaying these files is found in the IMDISP directory, although it is still a binary file (ZIP format) and so it is not suitable for mailing at this time. Any problems with the archive server should be reported to me as soon as possible. And as always, the archives are also available via anonymous ftp to ames (128.102.18.3). Directory is /pub/SPACE. -Peter Yee yee@ames.arc.nasa.gov ames!yee ------------------------------ End of SPACE Digest V13 #081 *******************