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 ; Sun, 22 Apr 90 02:00:36 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 22 Apr 90 02:00:06 -0400 (EDT) Subject: SPACE Digest V11 #302 SPACE Digest Volume 11 : Issue 302 Today's Topics: Re: Drake Equation (was Re: Interstellar travel) Re: Drake Equation (was Re: Interstellar travel) Re: Drake Equation (was Re: Interstellar travel) Re: Teenage Mutant Ninja Tomatoes Re: What happened with the Barium drop Re: Apollo 13, STS-1, Vostok 1 anniversaries Re: The effects of decompression Re: Decompression and 2001 Re: Is the moon upsidedown to NASA? Re: voyager images on cd Re: Space Tomatoes ---------------------------------------------------------------------- Date: 21 Apr 90 21:57:55 GMT From: zephyr.ens.tek.com!wrgate!mrloog!dant@uunet.uu.net (Dan Tilque) Subject: Re: Drake Equation (was Re: Interstellar travel) steve@nuchat.UUCP (Steve Nuchia) writes: >Still, it could easily be the case that the earth's brightest >spectral lines are at 50 and 60 Hz (remember, not all the >world is north america -- some places came even closer to >choosing the optimally fatal frequency than we did). Is this a figure of speach or is some low frequency actually fatal? --- Dan Tilque -- dant@mrloog.WR.TEK.COM ------------------------------ Date: 21 Apr 90 19:51:16 GMT From: calvin.spp.cornell.edu!johns@cu-arpa.cs.cornell.edu (John Sahr) Subject: Re: Drake Equation (was Re: Interstellar travel) In article <3619@minyos.xx.rmit.oz> rxtajp@minyos.xx.rmit.oz (Andrew Pettifer) writes: > >What about all those 50Hz power grids? >They would cause some beat frequencies, and i'm sure that the phase >relationships are drifting all the time, which would help to make the signal(?) >seem more random. To the extent possible, the power grids are "in phase" across the USA. However, 60 Hz probably isn't such a great place to go looking for radio sources. 1) 60 Hz is much lower than the "plasma frequency" of the ionosphere (greater than about 1 MHz everywhere on the Earth). 2) High power lines come in triples for three phase power, and the separation is much less than the wavelength at 60 Hz, so that the "radiated" energy field probably falls off faster than inverse square (inverse cube or maybe even fourth) even in the absence of an ionosphere. 3) It is very noisey at low frequencies beneath our ionospheric canopy. 4) It is also fairly noisy above, as natural geophysical processes generate "TMR," or Terrestrial Myriametric Radiation above the ionosphere. -- John Sahr, | Electrical Engineering - Space Plasma Physics johns@alfven.spp.cornell.edu | Cornell University, Ithaca, NY 14853 ------------------------------ Date: 20 Apr 90 01:14:58 GMT From: nuchat!steve@uunet.uu.net (Steve Nuchia) Subject: Re: Drake Equation (was Re: Interstellar travel) In article <3461@tymix.UUCP> pnelson@hobbes.UUCP (Phil Nelson) writes: > I hope this is not one of those often asked questions, what about 3000 >miles of wire sending gigawatts at 60Hz? I don't know if it's all in phase, >but big chunks of it are. I guess it would be better if all the wire was >running parallel, maybe a little further from the ground, but it is a lot >of power. Does anyone know what the propogation of say, 20-200Hz is? It propagates pretty well, and the overall grid will be phased to radiate in one direction or another at pretty much any time. The problems I can see are: 1) It is very regular. There is nothing special about the frequency. How will the BEMs know it isn't a pulsar? They could be scratching their ersatz-heads now and churning out PhD theses proposing models to explain the strange low frequency emitting, low-mass binary of that otherwise unremarkable yellow star. Just imagine how they'd ridicule you for suggesting it might be a planet. 2) The power companies work very, very hard to balance the currents in the lines, and the voltages are always well balanced. The field of a balanced pair (or triple) of point sources falls off as the _qube_ of distance. By the time you get to the far-field, where you can start considering the grid a point source (say, 1 AU or so) there will be surprisingly little power left. Another way to check the last point is to ask youself how long the power companies would stay in business if they were radiating a large fraction of the gigawatts they move around into space. Engineers make sure most of it gets where its going, not to the BEMs. Power costs money. Still, it could easily be the case that the earth's brightest spectral lines are at 50 and 60 Hz (remember, not all the world is north america -- some places came even closer to choosing the optimally fatal frequency than we did). Those lines are certainly among our narrowest. The most distinctive signals, the easiest to associate with intelligent life, are probably the ones from the early warning and ballistic missile defence radars. Gigahertz pulse trains, much narrower beams than broadcast entertainment, steered and deliberately propagated outside the atmosphere. If they happened to intercept a command sent to a far-off space craft, like the "wake up" messages occasionally sent out at very high power levels, that might get their attention too. Radio navigation beacons are a candidate too, and will remain so long after most entertainment broadcasting has gone to cable. Eventually they will be replaced by satellite systems, whose transmitters all point down. Maybe if we all turned on our microwave ovens at the same time ... ------------------------------ Date: 21 Apr 90 16:21:09 GMT From: frooz!cfa250!wyatt@husc6.harvard.edu (Bill Wyatt) Subject: Re: Teenage Mutant Ninja Tomatoes <> How about that announcement from NASA backpedalling on the possibility <> of the tomato seeds having mutated into toxic forms from the extra < One thing that struck me about this incident was when NASA officials < said that they wouldn't have any problem with eating a tomato from one < of these plants. Excuse my paranoia, but I don't think I would. It No. The chances that a mutation would leave a tomato apparently ok - smells ok, tastes ok, looks ok, but still poisonous are VERY VERY SMALL. Think about it - the bozo in NASA PR didn't. -- Bill Wyatt, Smithsonian Astrophysical Observatory (Cambridge, MA, USA) UUCP : {husc6,cmcl2,mit-eddie}!harvard!cfa!wyatt Internet: wyatt@cfa.harvard.edu SPAN: cfa::wyatt BITNET: wyatt@cfa ------------------------------ Date: 21 Apr 90 00:48:59 GMT From: van-bc!ubc-cs!fornax!zeke@ucbvax.Berkeley.EDU (Zeke Hoskin) Subject: Re: What happened with the Barium drop In article <4262@plains.UUCP>, overby@plains.UUCP (Glen Overby) writes: > In article <23582@netnews.upenn.edu> vinson@linc.cis.upenn.edu (Jack Vinson) writes: > >What happened with the barium canister that was to be released from > and I saw what I would normally consider to be Aurora. Not very exciting. It went like this: Friday: I read netnews as usual. Saturday: Thousands of people in Vancouver see huge glowing ball in the sky. The F.O. remained U for a very long time, despite calls to the local planetarium, astronomy depts, etc Sunday: The TV says it was the PEGSAT dump and gives accurate times to` see more. The sky is at this point normal for Vancouver, i.e. ceiling of about 100 feet. The clouds remain. Monday:I read netnews, which tells me retroactively about the dump. Drat. On a typical night, the Galactic Patrol could take on Boskonia two falls out of three over Vancouver and nobody would see. The first night I can ever remember with a clear sky and an interesting space event... snd nobody hears about it in time to look. ------------------------------ Date: 21 Apr 90 06:58:41 GMT From: nuchat!steve@uunet.uu.net (Steve Nuchia) Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries In article <89@newave.UUCP> john@newave.mn.org (John A. Weeks III) writes: >Duct Tape? Why on earth did they have duct tape on the Apollo? >How much did this flight certified duct tape cost? Did any of the >LM's that landed on the moon carry duct tape? This person obviously needs a clue. Don't tell anyone, but duct tape is The Force. It has a dark side, and a light side, and it binds the Universe together. Serisouly, there are two things no mission will leave the ground without. Duct tape is one. Extra self-adhesive velcro is the other. Drives Liz bananas, but the crew won't go without the velcro, and the duct tape is astoundingly useful, especially in zero-g where is it aproximately equivalent to a temporary weld. If you saw the video of the computer replacement job (I was glued to the NASA-Select feed for hours) you should have noticed all the tools and parts duct-taped to the bulkheads and lockers. Picture doing the job without it. Picture doing the job with the whole computer on a 6U card. But that's a different story. ------------------------------ Date: 20 Apr 90 11:30:02 GMT From: munnari.oz.au!metro!sunaus.oz!softway!otc!gregw@uunet.uu.net (Greg Wilkins) Subject: Re: The effects of decompression In article <1990Apr17.024040.318@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <3018@calvin.cs.mcgill.ca> msdos@calvin.cs.mcgill.ca (Mark SOKOLOWSKI) writes: >>I am wondering wheter or not a human body exposed to void would explode, > >Loss of air from the lungs is inevitable, but the rate would normally be >limited by other factors (e.g. how big the hole in the wall was), and the >only significant hazard would be rupturing your eardrums if you had a cold >or otherwise didn't get your ears depressurized properly. There is some >cooling effect from evaporation of sweat, much as there is in air, but >vacuum has no temperature and there is no reason why you would "rapidly >freeze". And your skin is a good grade of leather, and does a good job >(temporarily!) of holding in your body water. > >After ten minutes it would undoubtedly be different, but the only problem >with a brief exposure to vacuum is inability to breathe. >-- From Scuba diving experience, any time ambient pressure is halved, a person is in danger of decompression sickness (The bends). I understand this is why the shuttle crew must spend some time pre-breathing O2 before suiting up for a "out-of-vehicle-experience!!!:-)". Recompression alone will NOT cure the bends. Bubbles of gas formed in the blood stream are compressed, but not removed by recompression. As for damage to the brain/lungs/etc from stroke type injuries caused by circulation blockage, biochemical changes in the blood,..... etc etc (lots of nasty details deleted). Recompression therapy for the bends often involves pressures higher than those experience before the decompression, together with breathing pure O2 (always dangerous, more so when pressure is involved). May I suggest reading "Decompression in Depth - proceedings of the Seminar, PADI, 1243 East Warner Ave, Santa Ana, CA 92705". Decompression to vacuum is probably survivable -> But I doubt that it would be so with out medical complications. -gregw ------------------------------ Date: 20 Apr 90 12:55:00 GMT From: research!phacb@ucbvax.Berkeley.EDU (A.C.Beresford) Subject: Re: Decompression and 2001 People surviving in a vacuum is an old theme of Arthur C. Clark, I think he wrote an article about it in BIS Journal , many years ago , and has used it in several stories other than 2001. ------------------------------ Date: Sat, 21 Apr 90 07:04 CST From: Bill Higgins-- Beam Jockey Subject: Re: Is the moon upsidedown to NASA? Original_To: Orig_To! SPACE,BAXTER_A@WEHI.DN.MU.OZ Some time ago Alan Baxter ( zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!murdu!ucsvc!wehi!baxter_a@tut. c is.ohio-state.edu) explained: >In Australia, the full moon looks to have an image of a rabbit with >big ears on the left, with some buckshot passing by its left (right to us) >ear. XXXXXXX XXXXXXXXXXXXXXXXXX XX XXXXXXXXXXXXXXXXX XXX XXXX XXXXX XX XX XX mi XX ms XXXX mc XX X XXX XX X XXXX XXX XX XXXX X XXXXXXXXXX X XX X X mt X XXX XX \|/ XXXX mf XXXX XX -O- XXXXXXXX XX XXX XX /|\ XXXXXXXX XXXXXXXXXXX XXX op XXXXXXXXXXXXXXXXXXXXXXX XXXX XXXXXXXXXXXXXXXXXXXX XXXXX XXXXXXXXXXXXXXXXX XXXX X XXXXXXXXXXXXXXXXXXXX XXXXX X XXXX\|/X/XXXXXXXXXX XXXXXXX XXXXX-O-XXXXXXXXXX XXXXX XXXXX/|\XXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXX Here is my understanding of lunar geography (all right, "selenography"). My question: Where is the rabbit? North Key: _____________ OP Oceanus Procellarum (the big one) / \ MI Mare Imbrium / MI MS MC\ MS Mare Serenitatis / MT \ MT Mare Tranquillitatis ( OP MF ) MF Mare Fecunditatis \ / MC Mare Crisium (the little one all by itself) \ / \_____________/ South OP is a large dark feature covering much of the western half. MI is sort of a bay on this, and straddles the northern center region. MS, MT, and MF form a diagonal chain stretching from north central to southeast. MC is an isolated circular dark sea surrounded by bright highlands; I use it as the quickest way to check on the orientation of a lunar image. Please tell me which features make up which parts of the rabbit, that I may be enlightened. ______meson Bill Higgins _-~ ____________-~______neutrino Fermi National Accelerator Laboratory - - ~-_ / \ ~----- proton Bitnet: HIGGINS@FNALB.BITNET | | \ / SPAN/Hepnet/Physnet: 43011::HIGGINS - - ~ Internet: HIGGINS@FNALB.FNAL.GOV ------------------------------ Date: 21 Apr 90 07:24:55 GMT From: netcom!marcos@apple.com (Marcos H. Woehrmann) Subject: Re: voyager images on cd In article <1039@med.Stanford.EDU> rick@hanauma.stanford.edu (Richard Ottolini) writes: > >In fact the Neptune images are not yet released. Jupiter, Saturn and > >Uranus are available from NSSDC on CD-ROM. Sorry if someone alreay posted this and I missed it but what is the cost of the voyager image CD-ROMs from NSSDC? (And what is the address of NSSDC). marcos -- Marcos H. Woehrmann {claris|apple}!netcom!marcos | marcos@netcom "Bicycling is like an X-rated movie. If at all possible, you'd rather do it than watch it." -- Bicycling Magazine 05/90 ------------------------------ From: davidbrierley@lynx.northeastern.edu Date: Sat, 21 Apr 90 17:11:24 EST Subject: Re: Space Tomatoes Source-Info: From (or Sender) name not authenticated. During NASA's press conference held just after the tomato memo reached the press the officials stated that the tomatoes are safe and that they would eat them themselves if asked. They also mentioned that they don't want anyone to eat the tomatoes because it is the actual tomatoes that they wish to study. With that in mind I'm sure many of the fruit will be analyzed before they are eaten, if they are eaten at all. Although any mutations that might occur in the tomatoes are likely to be negative, there is still a chance that the mutation could have a beneficial effect (i.e. increased vitamin content, etc.). David R. Brierley Northeastern University ------------------------------ End of SPACE Digest V11 #302 *******************