Changes

===Radiocarbon dates for Thera===

===Radiocarbon dates for Thera===

After digging through the vast mantle of tephra, archaeologists found the remains of the Theran town Aktorini. There were no bodies in the remains of the village, indicating there were warning signs that were heeded by the residents before the full eruption. They left behind some storage jars with seeds. Short-lived vegetation such as seeds, when available, are always preferable for radiocarbon dating to larger vegetation specimens such as building lumber, because the dating of lumber reflects the time the tree was growing, which may have been decades before it was cut down and another unspecified length of time while it was in use in the building. These seed specimens were analyzed in a 2004 ''Radiocarbon'' article.<ref>"Dating the Volcanic Eruption at Thera," by Christopher Ramsey, Sturt Manning, and Marigrazia Galimberti, ''Radiocarbon'' 46 (2004), pp. 325-344), available [http://digitalcommons.library.arizona.edu/holdings/journal/issue?r=http://radiocarbon.library.arizona.edu/Volume46/Number1/ here]</ref> The results of this analysis placed the eruption of Thera between 1663 and 1599 BC at a 95% confidence level. Other results obtained from an olive branch with leaves still on it were in agreement: 1627 to 1600 BC with a 95% confidence level.<ref>''Science'' 312, April 28 2006, p. 508.</ref>

After digging through the vast mantle of tephra, archaeologists found the remains of the Theran town Aktorini. There were no bodies in the remains of the village, indicating there were warning signs that were heeded by the residents before the full eruption. They left behind some storage jars with seeds. Short-lived vegetation such as seeds, when available, are always preferable for radiocarbon dating to larger vegetation specimens such as building lumber, because the dating of lumber reflects the time the tree was growing, which may have been decades before it was cut down and another unspecified length of time while it was in use in the building. These seed specimens were analyzed in a 2004 ''Radiocarbon'' article.<ref>"Dating the Volcanic Eruption at Thera," by Christopher Ramsey, Sturt Manning, and Marigrazia Galimberti, ''Radiocarbon'' 46 (2004), pp. 325-344), available [http://digitalcommons.library.arizona.edu/holdings/journal/issue?r=http://radiocarbon.library.arizona.edu/Volume46/Number1/ here]</ref> The results of this analysis placed the eruption of Thera between 1663 and 1599 BC at a 95% confidence level. Other results obtained from an olive branch with leaves still on it were in agreement: 1627 to 1600 BC with a 95% confidence level.<ref>''Science'' 312, April 28, 2006, p. 508.</ref>

===Pottery dating of the Thera event===

===Pottery dating of the Thera event===

The fleeing residents left behind not only the jars containing grain, but also various other ceramic artifacts that archaeologists routinely use in assigning a date to the various strata in their excavations. The general pottery style found at Thera was the type called Late Minoan IA (LMIA), with distinctive spirals and floral motifs. This type of pottery was traded widely across the Mediterranean and in the Near Eastern countries. There were no examples of a successor style called Late Minoan IB (LMIB), which had motifs of octopi, dolphins, and other sea creatures. Therefore archaeologists were confident in dating the Theran pottery to some time around 1500 BC, the transition point between LMIA and LMIB. Further, one style of pottery found at Thera is found in Egypt but not in any context earlier than the 16th century BC, i.e. over 100 years later than the 1660-1600 bracket for the Thera eruption calculated by radiocarbon analysis.<ref>Ibid.,  p. 509.</ref> Archaeologists therefore date the Thera eruption at roughly 1500 BC or slightly later. The eminent Egyptologist Manfred Bietak maintains that the radiocarbon dates differ from what can be accepted archaeologically by 120 to 150 years.<ref>Ibid., p. 509.</ref> Other archaeologists agree. ""There are no current grounds for thinking that the Egyptian historical chronology could be out by more than a few years," says archaeologist Peter Warren of the University of Bristol, U.K. "This chronology has been constructed by hundreds of expert Egyptologists over many decades.""<ref>Ibid., p. 509.</ref>

The fleeing residents left behind not only the jars containing grain, but also various other ceramic artifacts that archaeologists routinely use in assigning a date to the various strata in their excavations. The general pottery style found at Thera was the type called Late Minoan IA (LMIA), with distinctive spirals and floral motifs. This type of pottery was traded widely across the Mediterranean and in the Near Eastern countries. There were no examples of a successor style called Late Minoan IB (LMIB), which had motifs of octopi, dolphins, and other sea creatures. Therefore, archaeologists were confident in dating the Theran pottery to some time around 1500 BC, the transition point between LMIA and LMIB. Further, one style of pottery found at Thera is found in Egypt but not in any context earlier than the 16th century BC, i.e. over 100 years later than the 1660-1600 bracket for the Thera eruption calculated by radiocarbon analysis.<ref>Ibid.,  p. 509.</ref> Archaeologists therefore date the Thera eruption at roughly 1500 BC or slightly later. The eminent Egyptologist Manfred Bietak maintains that the radiocarbon dates differ from what can be accepted archaeologically by 120 to 150 years.<ref>Ibid., p. 509.</ref> Other archaeologists agree. ""There are no current grounds for thinking that the Egyptian historical chronology could be out by more than a few years," says archaeologist Peter Warren of the University of Bristol, U.K. "This chronology has been constructed by hundreds of expert Egyptologists over many decades.""<ref>Ibid., p. 509.</ref>

===Residue from the eruption at other locales===

===Residue from the eruption at other locales===

Originally it was thought that some ash deposited in the Greenland ice pack that could be dated by ice-layer analysis supported the 1660-1600 date for the Theran eruption, but later chemical analysis showed that the ash came from some other volcano, so that this argument is now abandoned by Sturt Manning and the other physicists.<ref>''SCIEM'' 3, p. 28.</ref>  

Originally it was thought that some ash deposited in the Greenland ice pack that could be dated by ice-layer analysis supported the 1660-1600 date for the Theran eruption, but later chemical analysis showed that the ash came from some other volcano, so that this argument is now abandoned by Sturt Manning and the physicists.<ref>''SCIEM'' 3, p. 28.</ref>  

Another type of residue from a volcano is pumice. Pumice is a rock with myriads of glass-walled tiny bubbles that make it less dense than water, so that after a volcanic eruption it would have floated across the Mediterranean to many different shores. It was valued in antiquity as a scouring agent, a use which continues today in "Lava" soap.  

Another type of residue from a volcano is pumice. Pumice is a rock with myriads of glass-walled tiny bubbles that make it less dense than water, so that after a volcanic eruption it would have floated across the Mediterranean to many different shores. It was valued in antiquity as a scouring agent, a use which continues today in "Lava" soap.  

<blockquote>In addition to the pottery evidence, the contexts of waterborne pumice from the Theran eruption found in Egypt and the Near East have ben considered as evidence relating to the date of the eruption. At Tell el-Dab^ca, Theran pumice in large quantities was found at five locations, three of which the excavator believes were workshops active during the reign of Thuthmosis III and not abandoned until late in his reign or the following reign of Amenophis II, in any event after c. 1450 B.C. . . . Pumice from the Theran eruption has also been found in Eighteenth Dynasty, likely post-1525 B.C. contexts at Tell el^cAjjul and Tell Nami in Canaan.<ref>Malcom H. Wiener, "Times Change: The Current State of the Debate in Old World Chronology," in ''SCIEM'' 3, p. 40.</ref></blockquote>  

<blockquote>In addition to the pottery evidence, the contexts of waterborne pumice from the Theran eruption found in Egypt and the Near East have ben considered as evidence relating to the date of the eruption. At Tell el-Dab^ca, Theran pumice in large quantities was found at five locations, three of which the excavator believes were workshops active during the reign of Thuthmosis III and not abandoned until late in his reign or the following reign of Amenophis II, in any event after c. 1450 B.C. . . . Pumice from the Theran eruption has also been found in Eighteenth Dynasty, likely post-1525 B.C. contexts at Tell el^cAjjul and Tell Nami in Canaan.<ref>Malcom H. Wiener, "Times Change: The Current State of the Debate in Old World Chronology," in ''SCIEM'' 3, p. 40.</ref></blockquote>  

The "excavator" at Tell el-Dab^ca mentioned in this quote was Manfred Bietak. Bietak takes the "low chronology" for Egypt's Dynasty that places the reign of Tuthmosis III from 1479 to 1425 BC. (The "high chronology" of 1504 to 1450 BC is still held by some historians.) On p. 15 of ''SCIEM'' 3, Bietak has a chart that locates the Thera pumice in the palace district at Tell el-Dab^ca to about 1450 or 1455 BC.  

The "excavator" at Tell el-Dab^ca mentioned in this quote was Manfred Bietak. Bietak takes the "low chronology" for Egypt's Dynasty that places the reign of Tuthmosis III from 1479 to 1425 BC. (The "high chronology" of 1504 to 1450 BC is still held by some historians.) On p.&nbsp;15 of ''SCIEM'' 3, Bietak has a chart that locates the Thera pumice in the palace district at Tell el-Dab^ca to about 1450 or 1455 BC.  

This latest statement from Egyptologists, therefore, maintains that the 1663 to 1599 (median 1631) BC date for the eruption of Thera is about (1631 – 1450) = 180 years too early, in contrast somewhat with the earlier statements by Bietak<ref>''Science'' 28 April 2006, p. 509.</ref> that radiocarbon dates were too high by 120 to 150 years. This represents a movement away from, rather than toward, a compromise solution. The latest version of ''SCIEM'' (Vol. 3) carries on the debate, with no resolution in sight. Articles in ''SCIEM'' 3 by archaeologists Manfred Bietak, Felix Hoffmayer, and Kenneth Kitchen maintain that it is not possible to move Egyptian and related histories 100 or more years back in time, while Sturt Manning and other physicists insist that this must be done if archaeologists are to be consistent with the findings of "science." For those who are not familiar with the issues, the bias would be in favor of the physicists, since in the current culture physicists are higher on the totem pole than archaeologists. For those who are more acquainted with the actual facts of the case, however, there remains adequate reason for questioning the various assumptions that the physicists rely on to arrive at their results.

This latest statement from Egyptologists, therefore, maintains that the 1663 to 1599 (median 1631) BC date for the eruption of Thera is about (1631 – 1450) = 180 years too early, in contrast somewhat with the earlier statements by Bietak<ref>''Science'' 28 April 2006, p. 509.</ref> that radiocarbon dates were too high by 120 to 150 years. This represents a movement away from, rather than toward, a compromise solution. The latest version of ''SCIEM'' (Vol. 3) carries on the debate, with no resolution in sight. Articles in ''SCIEM'' 3 by archaeologists Manfred Bietak, Felix Hoffmayer, and [[Kenneth Kitchen]] maintain that it is not possible to move Egyptian and related histories 100 or more years back in time, while Sturt Manning and the physicists insist that this must be done if archaeologists are to be consistent with the findings of "science." For those who are not familiar with the issues, the bias would be in favor of the physicists, since in the current culture physicists are higher on the totem pole than archaeologists. For those who are more acquainted with the actual facts of the case, however, there remains adequate reason for questioning the various assumptions that the physicists rely on to arrive at their results.

==Possible explanations of the conflict==

==Possible explanations of the conflict==

It has been proposed by various observers that the Thera event itself may be responsible for the discrepancy between radiocarbon dates and archaeological dates in the middle of the second millennium BC. It is already recognized that a change in the earth's magnetic field will affect the number of cosmic rays reaching the upper atmosphere, and hence the number of C¹⁴ isotopes being formed, and this explanation is used as part of the explanation of why the C¹²/C¹⁴ ratio does not follow a straight line over the centuries, as compared to figures derived from [[dendrochronology]]. But a cataclysmic event can also distort the ratio of these two isotopes. Nuclear and thermonuclear tests in the late 1950s and early 1960s that were carried out mostly (entirely, for the thermonuclear events) in the South Pacific affected the C¹²/C¹⁴ ratio in both southern and northern hemispheres. If the Thera event gorged up old carbon material from inside the earth, then the distribution of the old carbon in the atmosphere would make any plant material than took it up to appear older than it actually was when measured in mass spectrometers some 3500 years later.  

It has been proposed by various observers that the Thera event itself may be responsible for the discrepancy between radiocarbon dates and archaeological dates in the middle of the second millennium BC. It is already recognized that a change in the earth's magnetic field will affect the number of cosmic rays reaching the upper atmosphere, and hence the number of C¹⁴ isotopes being formed, and this explanation is used as part of the explanation of why the C¹²/C¹⁴ ratio does not follow a straight line over the centuries, as compared to figures derived from [[dendrochronology]]. But a cataclysmic event can also distort the ratio of these two isotopes. Nuclear and thermonuclear tests in the late 1950s and early 1960s that were carried out mostly (entirely, for the thermonuclear events) in the South Pacific affected the C¹²/C¹⁴ ratio in both southern and northern hemispheres. If the Thera event gorged up old carbon material from inside the earth, then the distribution of the old carbon in the atmosphere would make any plant material that took it up to appear older than it actually was when measured in mass spectrometers some 3500 years later.  

This explanation, however, does not seem possible because of the olive branch that was buried in Thera's eruption. Growth rings in the branch represented 70 years of growth for the tree. Samples from various rings were subjected to radiocarbon analysis. The result was that the earliest rings returned values that measured about 70 years earlier than the latest rings and the leaves. This implies that if something had disturbed the atmospheric C¹²/C¹⁴ ratio for the mid-second millennium BC, the disturbance was in effect at least 70 years before the Thera eruption.

This explanation, however, does not seem possible because of the olive branch that was buried in Thera's eruption. Growth rings in the branch represented 70 years of growth for the tree. Samples from various rings were subjected to radiocarbon analysis. The result was that the earliest rings returned values that measured about 70 years earlier than the latest rings and the leaves. This implies that if something had disturbed the atmospheric C¹²/C¹⁴ ratio for the mid-second millennium BC, the disturbance was in effect at least 70 years before the Thera eruption.