I meant "peer" as opposed to "pier". Jim
On Wed, Mar 13, 2013 at 7:44 AM, Mendy Ouzillou <[email protected]> wrote: > Peter, > > No one disputes science is messy, but Jim's point is valid. Drs. Rubin and > Grossman have forgotten more than I will likely know in regards to > meteoritics, but I also feel a bit frustrated. I expect papers in a journal > like "Meteoritics and Planetary Science" to be thoroughly reviewed before > being published. It's not an issue of a few esoteric differences, it's about > the paper as a whole being rejected by esteemed and respected meteoriticists. > > Again, Jim's question is valid. Was this paper peer reviewed? I'm sure it > was, which leads to the next question. How was it allowed to be published if > it is so far off? > > The answer is important to me because I do not have the time to read > everything. I have time to read selected books and articles and want to make > sure I am properly furthering my education. > > Best, > > Mendy Ouzillou > > On Mar 13, 2013, at 10:05 PM, "Peter Scherff" <[email protected]> wrote: > > Hi Jim, > > I find this all delightful. Science is messy. Theories compete for > acceptance. The one that best fits the facts and is able to predict future > discoveries wins! > If I wanted absolute truths I would read books that the religions of > the world are based on. > Thanks, > > Peter > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Jim > Wooddell > Sent: Wednesday, March 13, 2013 9:46 AM > To: Meteorite List > Subject: Re: [meteorite-list] Origin of chondrules > > Hello Alan, Jeff, Mendy, > > I find this response somewhat bothersome. > > I recently read a paper that little old me, not being anyone close to being > a scientist, can shoot dozens of holes through because of the use of > outdated obsolete information and now I read this from Alan and Jeff, who I > look up to and consider piers in this field. > > The fact is, people read these papers, therefore they must be true!!! > It's like the TV commericial where the girl read something on the interenet, > so it must be true because no one can put stuff on the interent that isn't > true! > > So, what is going on with these papers? People are creating papers that are > supposed to be pier reviewed and here we have two piers shooting them down > in a public forum? What happen to the process of pier review and if this > particular paper is completely wrong! Who were the piers? > > I am not going to appologise for being a little critical about this but come > on guys, has it just become a paper mill? It sure beginning to seem that > way. I am completely missing the point of publishing papers with outdated > and obsolete information (when the new data is in > hand) and papers that we are reading completely wrong! > > I honestly do read these papers and try to ingest as much as I can, but here > of late, it seems I am completely wasting my time reading them and then I > read your responses! Arrrrrgh. > > Jim Wooddell > > > On Wed, Mar 13, 2013 at 3:28 AM, Jeff Grossman <[email protected]> wrote: >> I second what Alan wrote, at the 90% level. With my remaining finger, >> I'll add that the worst problem may be that these molten planetesimals >> must magically keep metallic and silicate melts mixed together in >> order to make chondrules, many of which have abundant metal. I think >> this would be physically difficult, to say the least. >> >> I think the ideas in this paper are philosophically quite attractive, >> joining modern research on cosmochronology with dynamical models of >> the disk. But despite this new way of thinking, the basic tenets are >> quite retro. Many people up through the 1960s hypothesized that >> chondrules were fragments of igneous rock. Then modern research on >> them began. Study after study found problems with these models, many of > which Alan outlined. >> Although the new model is a twist on the old ones, it still is subject >> to the same tests... and it cannot pass most of them. >> >> Jeff >> >> >> On 3/13/2013 2:03 AM, Alan Rubin wrote: >>> >>> I'll be happy to give my opinion on the paper. I think it is >>> completely wrong. Here is my reasoning: >>> 1. Many chondrules are surrounded by secondary igneous shells, still >>> others by igneous rims. These shells and rims indicate that the >>> chondrules haev experienced more than one melting event. >>> 2. Many FeO-rich (i.e., Type-II) porphyritic olivine chondrules >>> contain relict grains of different FeO contents and different >>> O-isotopic compositions, again indicating multiple melting. This is >>> very hard in a collision model. >>> 3. One might expect molten planetesimals to have well-mixed melts. >>> If the chondrules are mainly from the larger planetesimal (the >>> target) as one would expect, the O isotopic compositions of the >>> chondrules would probably be mass-fractionated and lie on a slope-1/2 >>> line on the standard three-isotope diagram. We don't see this. >>> 4. One might also expect that as the planestimal melted and began to >>> crystallize, it would become chemically fractionated, unlike the >>> unfractionated, solar, compositions of chondrules in primitive > chondrites. >>> 5. The occurrence of microchondrules in the fine-grained rims around >>> some normal-size chondrules and the apparent melting of pyroxene at >>> the outer surface of the chondrule to form the microchondrules >>> indicates chondrule melting by a mechanism capable of melting only >>> the outer surface of the chondrule. This is totally inconsistent >>> with the formation by splashing by the collision of molten planetesimals. >>> 6. There are correlations between chondrule size, the proportion of >>> different chondrule types, the proportion of those with igneous rims >>> and secondary shells that are difficult to explain by splashing but >>> come naturally to a model invoking multiple melting in dusty nebular > regions. >>> 7. The non-spherical shapes of most CO chondrules indicates very >>> rapid cooling or else they would have collapsed into spheres. This >>> might be okay except for the fact that the large size of their >>> phenocrysts require a growth period thousands of times longer than >>> the time it would take a molten droplet to collapse into a sphere. >>> This again indicates a flash heating mechanism. >>> 8. The fairly rare occurrence of chondrule-CAI mixtures are difficult >>> to explain by colliding molten planetesimals, but are sinple to >>> explain by melting of a mafic dustball that had and old CAI fragment > inside. >>> 9. Each chondrite group has its own distinctive narrow range of >>> chondrule sizes. In fact, about 90% of the chondrules in any group >>> have diameters within a factor of 2 of the mean size. One would >>> expect molten planetesimals to produce a similar size of chondrules range > for each group. >>> Furthermore, chondrule size is correlated with lots of other >>> chondrule properties (proportions of textural types, numbers with >>> rims and secondary shells, etc.) that are hard to explain by molten > planetesimals. >>> 10. And, I just don't see how we get the different chondrule textural >>> types by that model. Some chondrules lack olivine, others lack >>> pyroxene, some are coarse grained, some are fine-grained, some have a >>> mixture of different size grains, some include relict grains. This >>> seems impossible to produce by the molten planetesimal model. >>> Since I only have 10 fingers, I'll stop there. >>> >>> >>> Alan Rubin >>> Institute of Geophysics and Planetary Physics University of >>> California >>> 3845 Slichter Hall >>> 603 Charles Young Dr. E >>> Los Angeles, CA 90095-1567 >>> phone: 310-825-3202 >>> e-mail: [email protected] >>> website: http://cosmochemists.igpp.ucla.edu/Rubin.html >>> >>> >>> ----- Original Message ----- From: "Mendy Ouzillou" >>> <[email protected]> >>> To: "met-list" <[email protected]> >>> Sent: Tuesday, March 12, 2013 7:06 PM >>> Subject: [meteorite-list] Origin of chondrules >>> >>> >>> And now for something completely different ... Meteorite talk. >>> >>> >>> I am in the process of reading through a fascinating article in >>> latest issue of "Meteoritics and Planetary Science" called "The >>> Origin of Chondrules and Chondrites: Debris from Low Velocity Impacts >>> Between Molten Planetisimals." >>> >>> This paper is very well written and readable even by a novice such as >>> myself. What I find interesting is the proposal for a (somewhat) new >>> theory that chondrules did not instantly form from clumps of heated >>> nebular dust but instead formed 1.5 to 2.5MY after the formation of >>> CAIs. the paper states that chondrules formed from splashing when two >>> differentiated planetisimals collided at a relatively slow speed of > between 10 to 100m/s. >>> Without being able to review the previous papers, I have to say that >>> to me this makes a great deal of sense and appears to solve many of >>> the inconsistencies that have been raised in some of the older books >>> that I have read. >>> >>> Note: there is a typo in the paer on page 2177. Is states "A strength >>> of the splashing model is that it can explain why chondrules are >>> mostly between >>> 1.5 and 2.5MYr younger than CAI ...". The sentence should read >>> "older", no "younger". >>> >>> Dr. Jeff Grossman, would love to hear your thoughts on this paper. >>> >>> Mendy Ouzillou >>> ______________________________________________ >>> >>> Visit the Archives at http://www.meteorite-list-archives.com >>> Meteorite-list mailing list >>> [email protected] >>> http://six.pairlist.net/mailman/listinfo/meteorite-list >>> ______________________________________________ >>> >>> Visit the Archives at http://www.meteorite-list-archives.com >>> Meteorite-list mailing list >>> [email protected] >>> http://six.pairlist.net/mailman/listinfo/meteorite-list >> >> >> ______________________________________________ >> >> Visit the Archives at http://www.meteorite-list-archives.com >> Meteorite-list mailing list >> [email protected] >> http://six.pairlist.net/mailman/listinfo/meteorite-list > > > > -- > Jim Wooddell > [email protected] > 928-247-2675 > ______________________________________________ > > Visit the Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > [email protected] > http://six.pairlist.net/mailman/listinfo/meteorite-list > > ______________________________________________ > > Visit the Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > [email protected] > http://six.pairlist.net/mailman/listinfo/meteorite-list -- Jim Wooddell [email protected] 928-247-2675 ______________________________________________ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
