[meteorite-list] New KT asteroid injection theory PART ONE
From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Thu, 6 Sep 2007 14:46:58 -0700 (PDT) Message-ID: <238978.1089.qm_at_web36903.mail.mud.yahoo.com> Hi Sterling - Thanks much, but I have few more questions. As a completely oblivious reporter who started in on Clube and Napier's holocene comet impact story in 1997, I was blind sided in the bitter fight which Morrison (Ames, CA. ) was making to defend Muller (Berkeley, CA.). Now the questions: 1) Morrison always goes on about 100 million year asteroid impacts, never mentioning comets at 26 million year intervals. Did Muller change his hypothesis to fit the new data, and Morrison not catch up? 2) I think that Clube and Napier published well before Hills, with both Cosmic Winter and Cosmic Serpent. 3) This situation reminds me of ether and Einstein. NASA has spent (wasted) tens of millions of dollars looking for Nemesis and the result has been nada, nichevo, rien, zilch, nothing. The gravitational effects of our solar system passing through the plane of the milky way may probably have been misinterpreted as the gravitional effects of an imaginary companion, as per 18th century planet finding. Milani et al's calcs seem sufficient. (I hope memory has not failed me here.) The botton line here is that the bottom line from both theories is identical, we're entering a period of higher risk, while Griffin at NASA and others elsewhere seem to be doing little but working on the development of their hemerhoids. E.P. --- "Sterling K. Webb" <sterling_k_webb at sbcglobal.net> wrote: > Hi, EP, Paul, List, > > A problem here is that Bottke draws on this SAME > evidence to prove it's an asteroid, just as EP > points to > that evidence to prove it's a comet! > > The Chicxulub found fragment is carbonaceous, so > a carbonaceous asteroid is an obvious choice! But > since > the difference between a "comet" and an "asteroid" > seems > to be chiefly a matter of its degree of hydration > along a > continuum of formation, it could mean a comet, too. > (The > lack of comet samples to match the asteroid samples > that > we do have makes this an argument without evidence.) > > The "Nemesis" hypothesis is not Morrison's but > Richard > Muller's: http://muller.lbl.gov/pages/lbl-nem.htm , > published > in Nature (Davis, Hut, & Muller (v. 308, pp 715-717, > 1984)). > > The so-called "Nemesis" hypothesis is usually > badly > misunderstood. Everybody looked at the proposed 26my > eccentric orbit and blew it off as "unstable" on the > "short" > timescale of less than a billion years, which it is. > Because, > sooner or later a passing star would (will? has?) > perturbed > its orbit badly, altering in a major way, or setting > it free of > the Sun to wander on its own. It IS unstable over > the NEXT > billion years, but that's because, at solar > formation, its life > expectancy was about 5.0 to 5.5 billion years. 4.5 > down, > and a only little while to go... > > What they missed is that THAT has become the > chief > strong (rather than weak) point in Muller's theory: > http://muller.lbl.gov/papers/Lunar_impacts_Nemesis.pdf > , > where (2002) he revises his original 1984 > hypothesis, > to reflect new data. And, the conclusions of his > 2002 > paper on impacts have since been verified by other > (non-aligned) studies. Impacts are UP lately > ("lately" > meaning the last half billion years). > > Here's how "Nemesis" goes now. > > Imagine that the Sun has a nice little red dwarf > star > companion that you'd hardly notice in a stable and > not-too-eccentric orbit for billions of years, > causing no > harm, doing no damage, tossing no comets, because > it never comes close to its big brother star and its > private > herd of comets. > > THEN, about 0.5 to 0.8 billion years ago, a > passing > star perturbs that stable not-too-eccentric orbit > into the 26my > long elipse that clips through the Oort Cloud and > sets loose > the comets to fall into the inner system. (There are > nice > diagrams in that paper cited above, on Lunar > Impacts. > I love a good diagram...) > > And as long as we're arguing about the > attribution of > strong but unproven hypotheses, the "rain of comets" > to > the inner solar system by a big perturbation of the > Oort > Cloud was first suggested by Hills in 1981, NOT by > Napier > and Clube. They refined it slightly and pushed it, > but it's > not their baby, well, OK, adopted... > > Its chief disadvantage of "Nemesis" is that it > is a totally > ad hoc hypotheses and virtually impossible to prove > or > disprove, UNLESS you find the star. IF there is a > "Nemesis," > it will be found by the current "super-surveys" > (like Pan Starrs > or LSST) or future even more powerful All Sky > Surveys, > one of many thousand dim little stars that are > loitering in the > neighborhood and trying to look harmless. Just you > wait > thirty years or so... > > Muller is assuming that Nemmy is a little red > dwarf, but > it could also be an even smaller star, one of the > newly > discovered but numerous L-Class dwarves. Their > distribution > is such that, given that our star is typical, there > should be > a 50-50 chance of an L dwarf within 0.75 light year, > closer > than the original "Nemesis" star proposed distance. > (A light > year is 63,239.7 AU, more or less. The Oort Cloud > goes > out to 50,000 AU? 80,000 AU? Nobody knows...) So, an > L dwarf could be right on the edge of or even IN the > Oort > Cloud! Periodically, at least. > > There are at least TWO astronomers claiming > evidence > for a massive object perturbing the Ort Cloud, based > on > the anomalous distribution of Ort Cloud comet > aphelia: > http://www.ucs.louisiana.edu/~jjm9638/matese.html > http://neo.jpl.nasa.gov/news/news071.html > The only problem is that they are each pointing to a > different > patch of sky... Two perturbers are harder to swallow > than > one. I'll wait for a picture of Sol b. > > There is a big and delicate problem with all the > "nearby > star" proposals --- it has to be big enough to make > the comets > twitchy but NOT big enough to leave gravitational > fingerprints > on the solar system. > > This is getting long. Let's call it PART ONE. > > > Sterling K. Webb > ------------------------------------------------------------------------ > ----- Original Message ----- > From: "E.P. Grondine" <epgrondine at yahoo.com> > To: <meteorite-list at meteoritecentral.com> > Sent: Thursday, September 06, 2007 10:56 AM > Subject: [meteorite-list] New KT asteroid injection > theory > > > Hi Paul, list, > > The problem with this new theory is that what hit > appears to have been a comet: > > http://www.scn.org/~bh162/meteorite.html > > Furthermore, the injection mechanism has been > identified as gravity perturbations due to our solar > system passing through the plane of our galaxy, > which > theory agrees with 26 million year chaotically > cyclical pattern in mass extinctions: > > http://www.csmate.colostate.edu/cltw/cohortpages/viney_old1/massextinctionchart.html > > http://users.tpg.com.au/users/tps-seti/crater.html > > The physical evidence would seem to validate Clube > and > Napier's and the Italian dynamicists' work. > > Morrison's "Nemisis" hypothesis and Firstone's new > hypothesis both appear to be mistaken, and it is > most > likely that these gentlemen's are as well. > > E.P. Grondine > Man and Impact in the Americas > > > > > > > ____________________________________________________________________________________ > Be a better Globetrotter. Get better travel answers > from someone who knows. > Yahoo! Answers - Check it out. > http://answers.yahoo.com/dir/?link=list&sid=396545469 > ______________________________________________ > Meteorite-list mailing list > Meteorite-list at meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > > > ____________________________________________________________________________________ Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more. http://mobile.yahoo.com/go?refer=1GNXIC Received on Thu 06 Sep 2007 05:46:58 PM PDT |
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