Re: [meteorite-list] Meteorite Densities - Brother Guy
or for the cheap people ordinary playground white sand purchased at wal mart cheers Steve __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteorite Densities - Brother Guy
Hi, I thought this thread had died out. However, while Wal-Mart playground sand would give good results, you could try this: go to a construction materials dealer or a hardware store and get White Flint Sand (the ultimate playbox sand). The last time I bought some, it was definitely in 500-micron and smaller sizes. Wash the sand first to remove dust and fines. Then, sift some through a series of graduated screens until you find the grade of screen through which nothing passes. Use the next coarsest screen to get the finest particles. Unless you're measuring giant meteorites, the amount of sand required is not great. I searched for suppliers of volumetric glass beads. Most such beads are 3 to 6 mm in size and often irregular (and expensive). The beads used in the lab procedure described by Brother Guy were undoubtedly these: http://www.amazon.com/3M-Empore-Filter-Inert-microns/dp/B0017Y3KF0/ref=sr_1_15?s=industrialie=UTF8qid=1286391461sr=1-15 They are: 3M Empore Filter Aid 400; Inert Glass Beads Avg Dia. 40 microns; With Scoop; 1.5kg --- $107.49. 3M makes everything, doesn't it? $200 to $300 ought to be enough to measure meteorite density the same way. Here's 100 to 150 micron beads at $42/pound: http://www.amazon.com/Glass-Beads-0-1-0-15-mm/dp/B003NV7KOM/ref=sr_1_22?s=industrialie=UTF8qid=1286391774sr=1-22 Says the Wikipedia: As the term is used by geologists, sand particles range in diameter from 0.0625mm (or 1⁄16 mm, or 62.5 micrometers) to 2 millimeters. I suspect White Flint Sand sifted for its smallest sizes would likely fall into the 100-150 micron range. [Buying some White Flint Sand, sifting, and then measuring its particle sizes is left as an exercise for the student.] The smallest interstitial space of spheres in a lattice is 26% of the volume of the spheres, of cubes, about 50%. That volume is the error you introduce into the volume measurement (when multiplied by the surface area of the meteorite. The smaller the particle size, the smaller the error. The error introduced by measuring an one centimeter rock with 100 micron cubic particles (like sand) is approximately 0.05%. The error introduced by measuring it with 40 micron spherical particles is approximately 0.01%. Even the error with half- millimeter (500 micron) spherical particles is only 0.25%. The bigger the meteorite, the smaller the error. Doubling the size of the meteorite to 2 centimeters cuts the error in half, and doubling again to 4-cm to 1/4th of the 1-cm error. Measuring a less-than-2-inch meteorite with 100-micron sand has an error so small, you're almost certain to make a bigger error somewhere else... Publish your results. Sterling K. Webb - - Original Message - From: Steve Dunklee steve.dunk...@yahoo.com To: damoc...@yahoo.com; meteorite-list@meteoritecentral.com; volcano...@yahoo.com Sent: Wednesday, October 06, 2010 11:28 AM Subject: Re: [meteorite-list] Meteorite Densities - Brother Guy or for the cheap people ordinary playground white sand purchased at wal mart cheers Steve __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteorite Densities - Brother Guy
Hi all, I made a page years ago on this as it has always been a popular topic. The PDF paper is linked at the bottom: http://www.meteorites.com.au/oddsends/density.html Cheers, Jeff - Original Message - From: ted brattstrom volcano...@yahoo.com To: meteorite-list@meteoritecentral.com Sent: Friday, October 01, 2010 11:15 AM Subject: Re: [meteorite-list] Meteorite Densities - Brother Guy Aloha - This looks like a possible source of information - :-) Grain densities, Bulk Densities, and Porosity... Now to find a source of those tiny glass beads! Cheers - ted Stony Meteorite Porosities and Densities: A Review of the Data through 2001 D. T. BRITT1 and G. J. CONSOLMAGNO S.J http://homepage.mac.com/brother_guy/.Public/Meteorite%20Densities.pdf --- On Thu, 9/30/10, Richard Kowalski damoc...@yahoo.com wrote: From: Richard Kowalski damoc...@yahoo.com Subject: [meteorite-list] Amateur Meteoriticists? To: meteorite-list@meteoritecentral.com Date: Thursday, September 30, 2010, 3:05 PM David's original question got me snip .. Now to a more direct response to David. Over dinner Guy commented a bit about his work and how amateurs could perform density and specific gravity measurements of their own meteorites. I suggested contacting him, and other scientists for copies of their papers if you don't have access to pay sites. ...snip... I can't say he is looking for co-authors, but he may be able to direct interested amateurs to the researchers who would be interested. -- Richard Kowalski Full Moon Photography IMCA #1081 __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteorite Densities - Brother Guy
Aloha - This looks like a possible source of information - :-) Grain densities, Bulk Densities, and Porosity... Now to find a source of those tiny glass beads! Cheers - ted Stony Meteorite Porosities and Densities: A Review of the Data through 2001 D. T. BRITT1 and G. J. CONSOLMAGNO S.J http://homepage.mac.com/brother_guy/.Public/Meteorite%20Densities.pdf --- On Thu, 9/30/10, Richard Kowalski damoc...@yahoo.com wrote: From: Richard Kowalski damoc...@yahoo.com Subject: [meteorite-list] Amateur Meteoriticists? To: meteorite-list@meteoritecentral.com Date: Thursday, September 30, 2010, 3:05 PM David's original question got me snip .. Now to a more direct response to David. Over dinner Guy commented a bit about his work and how amateurs could perform density and specific gravity measurements of their own meteorites. I suggested contacting him, and other scientists for copies of their papers if you don't have access to pay sites. ...snip... I can't say he is looking for co-authors, but he may be able to direct interested amateurs to the researchers who would be interested. -- Richard Kowalski Full Moon Photography IMCA #1081 __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteorite Densities - Brother Guy
--- On Thu, 9/30/10, ted brattstrom volcano...@yahoo.com wrote: Now to find a source of those tiny glass beads! Seem to be pretty common at sand blasting suppliers. -- Richard Kowalski Full Moon Photography IMCA #1081 __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
