From ota Thu Jun 2 03:05:03 1988 Received: by angband.s1.gov id AA01148; Thu, 2 Jun 88 03:04:47 PDT id AA01148; Thu, 2 Jun 88 03:04:47 PDT Date: Thu, 2 Jun 88 03:04:47 PDT From: Ted Anderson Message-Id: <8806021004.AA01148@angband.s1.gov> To: Space@angband.s1.gov Reply-To: Space@angband.s1.gov Subject: SPACE Digest V8 #241 SPACE Digest Volume 8 : Issue 241 Today's Topics: Re: anthropic cosmological principle Re: anthropic cosmological principle P.C.W. Davies Books Re: anthropic cosmological principle Re: anthropic cosmological principle Re: Shooting the Moon Re: Cometesimals (was: Millions of comets hit Earth) Re: Shooting the Moon Re: Shooting the Moon Re: Question about Richard Hoagland/Mars Project Re: Shooting the Moon Re: Question about Richard Hoagland/Mars Project Re: Shooting the Moon (really Martian ballooning) (LONG) ---------------------------------------------------------------------- Date: 6 May 88 19:24:18 GMT From: wall@decwrl.dec.com (David Wall) Subject: Re: anthropic cosmological principle Marc Hairston recommends _The_Accidental_Universe_, and I do so also. It should be noted, however, that it is by A. J. P. Davies, not Paul Davies. I used to think they were the same (and they might be) but their books are quite different. My impression from reading them is that the former is a real scientist and the latter is a mystic. ------------------------------ Date: 6 May 88 21:28:16 GMT From: livesey@sun.com (Jon Livesey) Subject: Re: anthropic cosmological principle In article <429@bacchus.DEC.COM>, wall@decwrl.dec.com (David Wall) writes: > Marc Hairston recommends _The_Accidental_Universe_, and I do so also. > It should be noted, however, that it is by A. J. P. Davies, not Paul > Davies. I used to think they were the same (and they might be) but > their books are quite different. My impression from reading them is > that the former is a real scientist and the latter is a mystic. I have the book in front of me: P. C. W. Davies. The Accidental Universe Cambridge University Press. 1982. The jacket blurb begins "In 'The Accidental Universe" renowned expositor Paul Davies grapples with the most fundamental questions of all." Paul Davies is Professor of Theoretical Physics at the University of Newcastle upon Tyne (which used to be called King's College, Durham, when I was a tyke). Could you be thinking of A. J. P. Taylor, the historian? jon. ------------------------------ Date: 8 May 88 23:39:34 GMT From: amdahl!apple!dan@ames.arc.nasa.gov (Dan Allen) Subject: P.C.W. Davies Books It seems that Paul Davies also goes by P.C.W. Davies. His latest book from Simon and Schuster is called _The_Cosmic_Blueprint_ and is on the Scientific American reading level, along with: The Runaway Universe Other Worlds The Edge of Infinity God and the New Physics Superforce Then there are his "student texts": Space and time in the modern universe The forces of nature The search for gravity waves The accidental universe Quantum mechanics The ghost in the atom And finally there are his "technical" works: The physics of time asymmetry Quantom fields in curved space All of the above information came from the "Also by Paul Davies" page of his latest book, _The_Cosmic_Blueprint_. Editorial: I have about five of his books and find them pretty good on the whole. I particulary like his _The_Accidental_Universe_ which is a condensed version of the big Barrow & Tipler _The_Anthropic_Cosmological_Principle_ book which is also very good. His latest book (Cosmic Blueprint) is so-so. _God_And_The_New_Physics_ is the best of his easy reading level for me, because it has a neat philosophical side to it that the average science retelling does not have. I have not yet dived into his "technical" works, only because I have not seen them for sale. Does anyone have anything to say about them? One final comment: on my shelf of favorite books (the ones that I would take if on a desert island) I have the Barrow & Tipler, as well as two of Davies student level texts. For the curious, I also have Misner Thorne and Wheeler's _Gravitation_, Allen's _Astrophysical_Quantities_, Harwit's _Astrophysical Concepts_, Rindler's _Essential_Relativity_, Feynman's _QED_, Einstein's _The_Meaning_Of_Relativity_, Tolman's _Relativity_Thermodynamics_and_Cosmology, Eddington's _Space_Time_and_ Gravitation, and two other authors. F.S.C. Northrop's _Science_And_First_Principles_, a classic wonderful book by a man that I have heard so little about, and almost everything that KARL POPPER ever wrote. Keep in mind that this is my favorite shelf of physics books. The rest number in the 100s, and then there is computers, philosophy, religion... It is so hard to make a SHORT list of favorites. Try it sometime! Dan Allen Software Explorer Apple Computer ------------------------------ Date: 7 May 88 23:33:09 GMT From: mnetor!utzoo!yunexus!ists!mike@uunet.uu.net (Mike Clarkson) Subject: Re: anthropic cosmological principle In article <880502092353.edf@VLSI.JPL.NASA.GOV>, hairston%utd750%utadnx%utspan.span@VLSI.JPL.NASA.GOV writes: > Martin Gardner has written that the FAP should be renamed the > completely ridiculous anthropic principle (CRAP). I like that. > All the anthropic principles are interesting, but since none of them > can be tested or used to make predictions, then they fall outside of > science and into the realm of philosophy (which is nothing new to this > group). Not true: most of the anthropomoric principles centre around the assumption that carbon is a a requirement for life forms as we know them. It turns out that the relative abundance of carbon in the universe places some pretty severe restrictions on what must have transpired during the first second of the universe's existence after the big bang, so in fact the anthropomorphic principle does allow one to make predictions. One of the important early papers in this field was Dirac's paper in Nature (1961 I think, sorry I don't have the reference here). It began "It is well known that carbon is required to make physicists..." When you are working in quantum mechanics, the line between physics and philosophy is very thin; perhaps nowhere more so than in areas like the quantum theory of gravity. But it is most definitely science, and predictions can be made. Dirac was no philospher; he was an execellent and very practical scientist. Mike Clarkson mike@ists.UUCP Institute for Space and Terrestrial Science mike@ists.yorku.ca York University, North York, Ontario, uunet!mnetor!yunexus!ists!mike CANADA M3J 1P3 +1 (416) 736-5611 ------------------------------ Date: 11 May 88 23:18:17 GMT From: oliveb!3comvax!michaelm@ames.arc.nasa.gov (Michael McNeil) Subject: Re: anthropic cosmological principle In article <202@ists> mike@ists (Mike Clarkson) writes: >When you are working in quantum mechanics, the line between physics and >philosophy is very thin; perhaps nowhere more so than in areas like the >quantum theory of gravity. But it is most definitely science, and >predictions can be made. Dirac was no philospher; he was an execellent >and very practical scientist. I am now convinced that theoretical physics is actual philosophy. Max Born Michael McNeil ------------------------------ Date: 5 May 88 00:10:43 GMT From: tektronix!reed!douglas@ucbvax.berkeley.edu (P Douglas Reeder) Subject: Re: Shooting the Moon Does anyone know if the soviet mars probes that will travel around mars by balloon will deploy their balloons before or after first touching down? For those who haven't heard: The balloons are heated by the morning sun, adding to lift, drift with the winds during the day, and touch down every night at a different site. Doug Reeder ------------------------------ Date: 4 May 88 17:07:11 GMT From: mnetor!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Cometesimals (was: Millions of comets hit Earth) > >... Every few million years Mars warms up (since the water that is in > >vapor form creates a greenhouse effect just like CO2); the ice thaws; > >rivers flow on Mars... > > Water on Mars?? Could you please point me to references that > substantiate this? Well, nobody disputes the effects of water on the topography; the Viking Orbiter images settled once and for all that Mars once had flowing water on a large scale. The idea that Mars's climate changes cyclically, and that it is currently in a dry phase, is respectable speculation but not, I believe, unanimously accepted. Henry Spencer @ U of Toronto Zoology {ihnp4,decvax,uunet!mnetor}!utzoo!henry ------------------------------ Date: 4 May 88 17:36:11 GMT From: mnetor!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Shooting the Moon > If a telescope is too heavy/bulky/low in resolution, send down a > Ranger type probe first. This isn't a bad idea. The major problem is that you may need more than one of them to find a suitable location. > Load it with an impact-survivable transmitter, and you have a landing > beacon as well. This would allow a rather stupid but accurate > mechanism for terminal guidance. This isn't actually necessary if you can survey the landing area well enough. (Doing that from orbit should suffice, the only tricky part is picking the exact landing point.) Cruise-missile guidance systems should suffice to find a selected point in well-mapped terrain. Henry Spencer @ U of Toronto Zoology {ihnp4,decvax,uunet!mnetor}!utzoo!henry ------------------------------ Date: 4 May 88 17:41:04 GMT From: mnetor!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Shooting the Moon >1. EXPLOSION ON THE PAD: Folks, the Challenger disaster was bad, really >bad. But imagine if it had a nuclear warhead on board. Bye, bye South >Florida! A spaceship is one of the least stable places to keep a >warhead! Not an issue, actually. Nuclear warheads are routinely designed to crash at supersonic speeds or cook in a burning aircraft without doing much more than spraying a bit of radioactive gup around the immediate vicinity. Getting a nuclear explosion is not that easy; nuclear bombs are precision machinery. Smashing one with a sledgehammer won't detonate it. Henry Spencer @ U of Toronto Zoology {ihnp4,decvax,uunet!mnetor}!utzoo!henry ------------------------------ Date: 5 May 88 06:22:13 GMT From: well!pokey@lll-lcc.llnl.gov (Jef Poskanzer) Subject: Re: Question about Richard Hoagland/Mars Project In the referenced message, henry@utzoo.uucp (Henry Spencer) wrote: }Hoagland is generally regarded as a nut. Not by anyone who has even skimmed his book, and noted the extensive disclaimers that it's all wild speculation. This is very different from the Ancient Astronauts syndrome. I met Hoagland in 1980, and I did not find him nutty at all -- just intelligent, creative, open-minded, and slightly modest if you can believe that. Now, I don't actually believe this stuff about faces, and I don't think we should send *anything* to Mars until we have the infrastructure to stay there, but it is interesting. }I have not read this particular book Well then. ------------------------------ Date: 5 May 88 05:51:36 GMT From: paulf@shasta.stanford.edu (Paul A. Flaherty) Subject: Re: Shooting the Moon In article kr0u+@andrew.cmu.edu (Kevin William Ryan) writes: > Since what is wanted is a clear landing site, scout it out ahead of time. We will have an orbiter in LMO, but as I said earlier, the resolution isn't good enough. And that's with a big CCD camera, and optimistically precise optics. Moreover, terrain assessments done in the past have tended to be just plain wrong. Apollo 11 had to contend with unexpectedly rough terrain; they almost bought the farm. We got just plain lucky with Viking. > Now for my idea: If a telescope is too heavy/bulky/low in resolution, > send down a Ranger type probe first. Yep, we have said probes, but you can't get a camera with the necessary resolution, nor can you get enough power in the package to send back information at the required rate (Shannon et al). > kr0u@andrew.cmu.edu ------------------------------ Date: 5 May 88 16:42:30 GMT From: ddsw1!dino@gargoyle.uchicago.edu (Laura Watson) Subject: Re: Question about Richard Hoagland/Mars Project In article <1988May2.231928.4924@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >> I have just finished reading a book by one Richard Hoagland called >> _The Monuments of Mars_. It is essentially speculative nonfiction >> concerning some possible artificial objects on the surface of Mars. I read in Charles Berlitz's _Atlantis_ that there are pictures of pyramids on Mars. This was in the part about pyramids found under the Atlantic ocean, supposedly where Atlantis was. If the book you're talking about is about that, I sure going to read it. Laura Watson ...[ihnp4, moss, codas]!ddsw1!dino ------------------------------ Date: 6 May 88 01:19:55 GMT From: jeric@tybalt.caltech.edu (J. Eric Grove) Subject: Re: Shooting the Moon (really Martian ballooning) (LONG) In article <9179@reed.UUCP> douglas@reed.UUCP (P Douglas Reeder) writes: >Does anyone know if the soviet mars probes that will travel around mars >by balloon will deploy their balloons before or after first touching >down? > >For those who haven't heard: The balloons are heated by the morning >sun, adding to lift, drift with the winds during the day, and touch >down every night at a different site. As I understand it, the concept actually employs two balloons, a He (or H) balloon which, in answer to your question, is inflated on descent, and an open hot "air" balloon (maybe better called a "Montgolfier") made of some black material yet to be developed. Since the balloon fabrics are so fragile (presumably only a couple tenths of mils thick), they must not touch the Martian surface. Because the Martian atmosphere is so tenuous, Montgolfier ballooning is difficult, and every extra bit of weight must be eliminated. I recently heard a fellow from JPL talk here (sorry, his name has long since been filed) about the project. It is a French concept, and the JPLers were contributing to the design of the balloons and payload. Our government has, in its infinite wisdom, canceled their funding, so the French and Soviets will have to go it alone. The JPLers did make some significant advances in removing some of of the inherent problems in the concept, namely ... When the payload is on the ground at night, the Montgolfier is deflated and being held aloft by the He balloon. If there is any wind, the Montgolfier will act like a beautiful spinnaker, dragging the payload and pulling itself into the ground (bye-bye balloon). And if the payload drags, it may catch and be stuck forever. What we need is a balloon with a lifting shape (too complex to put in ascii) and a "smooth" payload. The JPLers came up with a lifting shape after much head-scratching, only to discover you can buy toy kite-balloons at K-Mart for a couple of bucks with just the right shape :-) (but much too heavy and small). They designed a snake-like payload of nested "dixie cups" to give rigidity on small scales, but flexibility on large scales. So with the wind blowing to the right, we might see this on Mars: He kite-balloon / / / deflated Montgolfier / / / / 0 0 0 000000 <- the payload Tests of the kite-balloon and the payload on the only Martian surface we Americans can reach (the CA desert) were quite successful. Now, designing instruments to fit in a series of squashed dixie cups might not be so simple. The French were impressed, but it's not yet clear whether or how much of the design will actually be used. disclaimer: I have no connection whatsoever with K-Mart. I don't even know where one is. J. Eric Grove jeric@tybalt.caltech.edu ...rutgers!cit-vax!tybalt.caltech.edu!jeric ------------------------------ End of SPACE Digest V8 #241 *******************