User talk:Tacahill

Vinland Map PIXE
I am writing to clarify my recent removal of your edit to the introduction of the article Vinland map.

It became apparent during the research for a response to Garmon Harbottle's paper in Archaeometry (vol. 50, 2008, pp177-189, DOI: 10.1111/j.1475-4754.2007.00378.x) that the elemental concentration figures given in the 1987 Analytical Chemistry presentation of the UC Davis PIXE analyses of the Vinland Map and its associated documents, despite the assurance of "formal quality assurance protocols", came within the sphere of the famous Sherlock Holmes dictum: "when you have eliminated the impossible, whatever remains, however improbable, must be the truth". The Davis PIXE figures are improbable by a factor of a thousand or more (as noted in the published response to Harbottle, Archaeometry vol. 50, 2008, pp887-893, DOI: 10.1111/j.1475-4754.2008.00428.x) and actually impossible by a factor of several hundred. Given their internal consistency (as illustrated, for example, in Figure 5 of the 1987 paper) the most parsimonious explanation is that they are exactly 1,000 times too small, and that all figures for the Vinland Map and Tartar Relation/ Speculum Historiale expressed in the 1987 paper as "ng/cm^2" are actually micrograms per square centimetre.

To help with further assessment of the situation, could you confirm to me, via a response on this page, the collimation arrangement for the proton beam? It is stated in the 1987 paper to be "collimated to 1.0 mm x 0.5 mm"- can you confirm that this means the adjustable collimator was set so that the beam getting through was 1.0 mm horizontally by 0.5 mm vertically (and if not, could you give details of the actual dimensions/orientation of the rectangular aperture)?

David Bradbury / David Trochos (talk) 21:25, 26 December 2014 (UTC)

Tacahill (talk) 15:22, 31 December 2014 (UTC) Tom Cahill Thank you for taking the time to providing oversight to Wikipedia editing. It is an essential step for protecting your credibility.

Last first - yes, we set a collimator to give typically 1.0 mm x 0.5 mm for inked lines, but used a slightly larger collimator 2.0 mm x 0.5 mm for analysis of the parchment to get better sensitivity.

This also provides us an opportunity to clarify the distinction between the non-destructive analyses of the map by energetic beams versus those that require removal of materials from the map for subsequent analyses. Finally, as I am sure you know all too well, articles that include input from fervent advocates are a constant threat to the impartiality we depend on. This article has been torqued out of factual alignment by such advocates, resulting in factual errors, opinions stated as facts, and biased references in the literature. This article can be greatly improved by only limited changes. My points are: 1.	Fairness. It is unfair to cite a reference and then neglect to give the conclusions of the reference before attacking it. 2.	Accuracy a.	There are numerous factual errors, including b.	 inaccurate and incomplete references that would prevent you readers from addressing primary sources (one of the great advantages of Wikipedia),. 3.	Perspective. The Vinland map study should be placed into the perspective of other, similar work, not just as a stand-alone study. 4.	Fact	Decades of use of PIXE in analyses similar to that of the Vinland Map attest to their accuracy and precision. a.	I was a pioneer of the non-destructive PIXE method, , b.	I was one of 5 laboratories chosen by NIST to develop Standard reference method materials for PIXE and XRF laboratories, now used around the world, c.	I applied it millions of times in my 27 years of analysis of thin air filters, some of which were make of paper and thus similar to documents. . d.	 The entire US national park network depended on the accuracy and precision of these data, including testimony EPA hearings, court cases and before Congress, usually under oath. In addition, I believe McCrone’s actually optical and SEM analyses are largely correct. So why all the controversy? I believe it is rooted in the differences of method: 1.	We analyzed the document nondestructively, allowing re analysis and quality assurance checks impossible when samples must be removed from the map. 2.	Specifically, McCrone (whose eyesight was terrible) asked a technician with no prior experience in documents to remove the samples. 3.	We worked with a team of experts, all listed as authors. McCrone worked alone, not even listing his technician, Anna Teetsov, with no prior experience with documents of any kind (that we can find in the per reviewed literature). This made his conclusions highly suspect to the Smithsonian, which asked us to do the analyses. First I will address the insertion I made into the summary. 1.	We have done thousands of analyses before, and more after, the analysis of the Vinland map. Most are in per reviewed journals. This includes well over 130 on manuscripts (see Appendix A). 2.	With a team of manuscript experts, historians, chemists, and microscopists, we examined and took scores of color micro-photographs of the map, some of which are included in the improperly cited article,. 3.	Our transects of a line, possible because of our milli-probe PIXE beam, saw a rimmed ink with the back residue showing titanium, and several other metals. 4.	These photos showed that in fact almost no ink at all was present in the yellow brownish lines, merely a stain in the parchment. Those stains included residues of a linseed oil like material. (Appendix B) 5.	It was in the black residues that we saw titanium and many other metals, and a few large bright crystals. This is the source of the statement “…similar to others ….” 6.	In the 1987 paper, we attempted to forge a manuscript using titanium paint, then repeatedly erasing the line until it was barely visible. . The residual was on the order of 70,000 ng/cm2, not the maximum of 10.2 ng/cm2 we saw. 7.	Similar documents were examined at the UC Berkeley Bancroft Library by historian Prof Richard Schwab, who found many examples on the mis-gauging that McCrone sited as proof of his double inking hypothesis (20th century titanium paint for the brownish yellow line, black ink overlay). .

I would propose that text be added explaining the difference with a non destructive analysis by a focused beam in an as-is condition (giving results in ng/cm2) versus any method that must remove samples for later analyses (giving results in micrograms of mass per crystal). I would include a statement that we think McCrone’s actual measurements are essentially correct on his crystals, but the differences arise from the selection and removal of crystals by an inexperienced technician. Finally, while I have taken no position on the authenticity of the Vinland Map (unlike many of the other editors), I am impressed that the C14 date is right on the date of the conference at which a map of the world was generated. Note that my manuscript experts have seen no large blank pieces of parchment of any date that a forger could use, since it was worth so much. Finally, if I were a 1950s forger, I would never have written the many paragraphs of reference on the map. Any error in the Latin could have made the whole effort a failure. Note also that one of the statements made about Vinland was later confirmed archaeologically.

Appendix A Peer reviewed literature using the PIXE technique on historical materials mostly documents. Publications and book chapters relating to analysis of historical and art objects by proton induced x-rays (PIXE) at UC Davis. (the CHAPs program – 1978-1995). These include both regularly published journal (16) and ad-hoc Symposia Proceedings, with the journal articles and book chapters, (generally >> 10 pages), with the first author’s name in bold.

Thomas A. Cahill, and Bruce Kusko. Compositional and Structural Studies of the Vinland Map and Tartar Relation. xxix – xxxix, in The Vinland Map and the Tartar Relation, R.A. Skelton, Thomas E. Marston, and George O. Painter, Yale 	University Press, 1995

McColm, D.W. and T.A. Cahill. The temperature profile of a microprobe. Nuclear Instruments and Methods in Physics Research. B54, Pp. 91-97 (1991). (analysis 	of non-destructive nature of PIXE on papers)

McColm, Douglas W. and Thomas A. Cahill. Central temperature of convectively 	cooled thin targets during ion beam analysis. Nuclear Instruments and 	Methods in Physics Research, North-Holland. B51:196-197 (1990) (analysis of 	non-destructive nature of PIXE on papers)

Cahill, T.A., Kusko, B., Eldred, R., Schwab R. Compositional comparison of the Mark Hoffman "Oath of a Freeman" and the "Whole Book of Psalms". In 	The Judgment of Experts. Essays and Documents about the Investigation of the Forging of The Oath of a Freeman, J. Gilreath, Editor. American Antiquarian Society 1991, pp 75-96.

Cahill, Thomas A. Accelerators for dating and forensics. Fermilab Industrial 	Affiliates Ninth Annual Meeting. Fermilab Industrial Affiliates Roundtable on Applications of Accelerators. Richard C., Jr., Editor. Pp. 91-114, May 26-27 (1989).

Gill, T.E., B.H. Kusko, C. Higgins, S. Howard, and T.A. Cahill. Site variation in provenance studies: The Carrara Marble example. Proceedings of the International Archaeometry Symposia. Toronto, Ontario, May. R. Farguhar, R. Hancock, and L. Pavlish; Editors. 26:210 219 (1988).

Kusko, Bruce H. Cyclotron analysis of paper and ink reveals secrets of the written 	and printed work. Special Session on dating manuscripts: Current scientific 	techniques for the identification of paper and ink. San Francisco, CA, December 28, 1987. Literary Research. Marcuse, M., Editor. Vol. 13, Nos., 2 & 3, pp. 123-133 (1988).

Cahill, T.A., R.N. Schwab, B.H. Kusko, R.A. Eldred, G. Moller, D. Dutschke, D.L. Wick, and A.S. Pooley. The Vinland Map, revisited: New compositional evidence on its inks and parchment. Analytical Chemistry. 59:829-833 (1987).

Kusko, B., Schwab, R. Historical analyses by PIXE. Fourth International PIXE Conference, Tallahassee, FL, June 9-13, 1986. Nuclear Instruments and Methods in Physics Research. B22:401-406 (1987).

Cahill, Thomas A. The nuclear bibliophile: Cyclotron studies of rare documents. Fourteenth Congress of the International Association of Bibliophiles. San Francisco, CA, September 30-October 11, 1985. Transactions. Stephen Tahn, Editor. Pp. 37 50 (1987).

Schwab, Richard N., Thomas A. Cahill, Bruce H. Kusko, Robert A. Eldred, and Daniel L. Wick. The proton milliprobe ink analysis of the Harvard B42, Volume II. PBSA. 81:4, Pp. 403-432, December (1987).

Cahill, Thomas A., Douglas W. McColm, and Bruce H. Kusko. Control of temperature in thin samples during ion beam analysis. Nuclear Instruments 	and Methods. B14:38 44 (1986). (analysis of non-destructive nature of PIXE on papers)

Kusko, Bruce, H. Proton milliprobe analysis of the handwritten annotations in J. S. 	Bach’s Calov Bible. The Calov Bible of J. S. Bach. Cox, H., Editor. 1986.

Schwab, Richard N., Thomas A. Cahill, Bruce H. Kusko, Robert A. Eldred, and Daniel L. Wick. Ink patterns in the Gutenberg New Testament: The proton milliprobe analysis of the Lilly Library copy. Papers of the Bibliographical Society of America (PBSA). 80, 3rd qtr:305 331 (1986).

Kusko, B.H., S. Howard, T.A. Cahill, C.G. Higgins, and D. Evans. Accelerator based analyses and the provenance of ancient marbles. Proceedings of International 	Symposium on Archaeometry. Athens, Greece, May 19 24 (1986).

Eldred, Robert A., Bruce H. Kusko, and Thomas A. Cahill. The external PIXE 	milliprobe at Davis: Laser alignment, PIXE calibration, and quality assurance. Nuclear Instruments and Methods. B3:579 583 (1984).

Kusko, B., T.A. Cahill, R., Eldred, R., Schwab, R. Proton milliprobe analyses of the Gutenberg Bible. Nuclear Instruments and Methods. B3:689 694 (1984).

Bauman, S., P.D. Houmere, J.W. Nelson, R.A. Eldred, and T.A. Cahill. PIXE analysis 	of intermediate and thick targets via line intensity ratios. Nuclear Instruments 	and Methods. B3:203 205 (1984). (correction for Gutenberg paper x-ray 	attenuation protocol)

Cahill, T.A., B.H. Kusko, R.A. Eldred, and R.N. Schwab. Gutenberg's inks and papers: Non-destructive compositional analyses by proton milliprobe. Archaeometry. 26.1:3 14 (1984).

Howard, S., T.A. Cahill, N. Herz, C. Higgins, E. Kinmonth, and B.H. Kusko. Computer-assisted accelerator-based methods of determining the provenance 	of ancient marbles. Symposium for Archaeometry. Pisa, Italy, September 	24 27. Automatic Processing of Art History Data and Documents. Laura Corti, 	Editor. Regione Toscana Publishers, Vol. 2, Pp. 258 271, 358 359 (1984).

Eldred, Robert A. External beam PIXE programs at the University of California, Davis. Invited paper and abstract for 7th Conference on the Application of 	Accelerators in Research and Industry, North Texas University, Denton, TX. IEEE Transaction on Nuclear Science. NS-30:1276-1279 (1983). (S)

Schwab, Richard N., Thomas A. Cahill, Bruce Kusko, and Dan Wick. Cyclotron analysis of the ink in the 42-line bible. Papers of the Bibliographical Society of America. 77.3:285 315 (1983).

Hill, M.W., L.D. Hansen, N.F. Mangelson, K.J. Faucette, D.J. Eatough, T.A. Cahill, and 	B. Kusko. Measurement of sample temperatures reached during proton and alpha particle irradiation of thin PIXE targets. Nuclear Instruments and Methods. 181:69 70 (1981). (analysis of non-destructive nature of PIXE on papers)

Cahill, T.A., B. Kusko, and R.N. Schwab. Analyses of inks and papers in historical documents through external beam PIXE techniques. Nuclear Instruments and Methods. 181:205 208 (1981).

Appendix B

Portions of a Power Point from a talk I gave at St. Louis University. I don't think I can insert kit, but if you respond to this e mail, I will send.

Vinland Map (2)
Thank-you for your detailed response.

I'll return to the collimation problem later, but for now, I hope you can help me to eliminate the impossible. On page 829 of your original 1987 report in Analytical Chemistry, you state that your PIXE technique "gives a minimum detectable limit of a few parts per million by mass of the sample in 2 min". Does this mean that the lowest commonly-found figure of 0.2 nanograms per sq. cm. (as given for various measurements in Table 1) should thus be equivalent to "a few" nanograms in a milligram of sample? David Trochos (talk) 20:31, 1 January 2015 (UTC)