The Shroud of Turin: Uncertainties of Carbon 14 Dating

General Information On Carbon Dating LSC Method- Liquid Scintillation Spectrometry LSC Method- Liquid Scintillation Spectrometry GPC Method- Gas Proportional Counting GPC Method- Gas Proportional Counting AMS Method- Accelerator Mass Spectrometry AMS Method- Accelerator Mass Spectrometry

History of the Shroud of Turin Known History Known History : Lirey, France : Lirey, France : Saint Hippolyte-sur-Doubs : Saint Hippolyte-sur-Doubs : Chambery : Chambery 1532: Damaged in fire at Chambery 1532: Damaged in fire at Chambery : Various Locations : Various Locations 1506: Pope Julius II declared the Shroud to be authentic 1506: Pope Julius II declared the Shroud to be authentic Present: Kept at Turin, Italy Present: Kept at Turin, Italy Speculated Pre-1357 History Speculated Pre-1357 History 30-57: Edessa, present day Turkey 30-57: Edessa, present day Turkey 57: Disappeared 57: Disappeared 525: Found 525: Found 944: Constantinople 944: Constantinople 1204: Disappeared 1204: Disappeared

Testing the Shroud AMS Method- AMS Method- In this method, a sample of complex organic molecules is oxidized into a compound (C/CO2) which is then negatively charged by an ion source. An accelerator system separates the positively charged carbon 14 particles and is detected and counted by a detector system. In this method, a sample of complex organic molecules is oxidized into a compound (C/CO2) which is then negatively charged by an ion source. An accelerator system separates the positively charged carbon 14 particles and is detected and counted by a detector system. Was the method used because it only required samples 7cm 2 in size. Other methods need samples to be 500cm 2. Was the method used because it only required samples 7cm 2 in size. Other methods need samples to be 500cm 2. Three tests- Three tests- ETH, Zurich, Switzerland ETH, Zurich, Switzerland University of Oxford, UK University of Oxford, UK University of Arizona, USA University of Arizona, USA

Rules for Testing Blind testing- Blind testing- Four samples, three controlled. Four samples, three controlled. Controlled samples were also linen, their age was known. Controlled samples were also linen, their age was known. Scientists did not know which sample was from the Shroud. Scientists did not know which sample was from the Shroud. Cleaning- Cleaning- To reduce the effects of contamination, the samples were cleaned. To reduce the effects of contamination, the samples were cleaned. The labs did not use the same methods or chemicals. The labs did not use the same methods or chemicals.

Results The results of the radiocarbon testing at Arizona, Oxford, and Zurich labs give the age range of the Shroud of Turin from AD with 95% confidence. The results of the radiocarbon testing at Arizona, Oxford, and Zurich labs give the age range of the Shroud of Turin from AD with 95% confidence. The age can be placed between AD 1292 and 1358 with 66% confidence. The age can be placed between AD 1292 and 1358 with 66% confidence. None of the measurements from the twelve sets of tests (four textile samples at each of the three laboratories) differ much from the appropriate mean value (none by more than two standard deviations). None of the measurements from the twelve sets of tests (four textile samples at each of the three laboratories) differ much from the appropriate mean value (none by more than two standard deviations). This provides conclusive evidence that the linen of the Shroud of Turin is Medieval—this does not necessarily imply a ‘forgery’ but perhaps an icon. This provides conclusive evidence that the linen of the Shroud of Turin is Medieval—this does not necessarily imply a ‘forgery’ but perhaps an icon.

Uncertainties Inherent to Testing Fractionation – thermo-induced fractionation. Fractionation – thermo-induced fractionation. Enhances the carbon 14 count Enhances the carbon 14 count Cosmic Ray production Cosmic Ray production Magnetic Cycle of the Earth Magnetic Cycle of the Earth Nuclear Bomb testing Nuclear Bomb testing Fossil Fuel Fossil Fuel

Other Uncertainties Fires- In 1532, a fire severely damaged the church at Chambery where the Shroud was being kept. Fires- In 1532, a fire severely damaged the church at Chambery where the Shroud was being kept. Carbon Dioxide contamination. Carbon Dioxide contamination. Other chemical changes due to heat. Other chemical changes due to heat. Poke Holes-damage done in 1516 Poke Holes-damage done in 1516 Silver burn Silver burn Trial by fire- authenticity Trial by fire- authenticity Legend Legend Biochemical layer Biochemical layer Repairs- In 1534, Poor Clare Nuns sewed thirty patches into the Shroud to fix damage done by the fire at Chambery Repairs- In 1534, Poor Clare Nuns sewed thirty patches into the Shroud to fix damage done by the fire at Chambery

Reconsideration of 1988 Shroud of Turin Radiocarbon Tests Suppose you conduct a series of ten measurements of two observations each to determine the radiocarbon age of a sample. The results of the measurements are shown below: Suppose you conduct a series of ten measurements of two observations each to determine the radiocarbon age of a sample. The results of the measurements are shown below:

Reconsideration continued Applying standard statistical measurements to this population of observations results in the following: Applying standard statistical measurements to this population of observations results in the following: Arithmetic Mean RC age: 600 Error: +/ Error: +/ Applying the statistical techniques employed in dating the Shroud in 1988 results in the following statistical measures: Applying the statistical techniques employed in dating the Shroud in 1988 results in the following statistical measures: Mean RC age: 600 Error: +/ Error: +/- 3.35

Reconsideration of 1988 Shroud of Turin Radiocarbon Tests Next, assume the last five measurements are modified in the manner shown below: Next, assume the last five measurements are modified in the manner shown below:

Reconsideration Continued The standard statistical data now become: The standard statistical data now become: Arithmetic Mean RC age: 615 Error: +/ Error: +/ Using the Wilson & Ward statistical techniques employed in the 1988 dating of the Shroud sample yields: Using the Wilson & Ward statistical techniques employed in the 1988 dating of the Shroud sample yields: Mean RC age: 615 Error: +/ Error: +/- 3.35

No Possibility of Finding Ultimate Proof of Age in Radiocarbon Dating “No responsible field archaeologist would trust a single date, or a series of dates on a single feature, to settle a major historical issue, establish a site or cultural chronology…” “No responsible field archaeologist would trust a single date, or a series of dates on a single feature, to settle a major historical issue, establish a site or cultural chronology…” “No responsible radiocarbon scientist would claim that it was proven that all contaminants had been removed and that the dating range produced for a sample was without a doubt its actual calendar age” “No responsible radiocarbon scientist would claim that it was proven that all contaminants had been removed and that the dating range produced for a sample was without a doubt its actual calendar age”

Current Plans for Testing It is obvious the uncertainties of the results number so greatly that the dated age of the Shroud is seriously questionable. It is doubtful that the Pope would allow new tests to be done. It is obvious the uncertainties of the results number so greatly that the dated age of the Shroud is seriously questionable. It is doubtful that the Pope would allow new tests to be done.