Geomagnetic archaeology 地磁考古

Geomagnetic archaeology 地磁考古

Earth’s magneticfield illuminates biblical history

第一段：

When sennacherib, King of Assyria, sent his army to the kingdom of Judah in 701BC, and had it destroy the city of Lachish, 43km south-west of Jerusalem, he was doing his bit for science as well. As Yoav Vaknin of Tel Aviv University told this year’s meeting of the American Geophysical Union, held in New Orleans and online, residual magnetism in the burnt-down buildings is helping archaeologists to date other finds in the area. It also helps geophysicists to chart the ups and downs of terrestrial magnetism.

公元前701年，亞述王西拿基立出兵攻打猶大王國，摧毀了耶路撒冷西南43公里的拉吉城，這也是他為科學(xué)所做的貢獻。正如以色列特拉維夫大學(xué)的Yoav Vaknin教授今年在新奧爾良舉行的美國地球物理聯(lián)盟會議上所說的那樣，被燒毀的建筑物中的殘余磁力正在幫助考古學(xué)家確定該地區(qū)其他發(fā)現(xiàn)的年代。它還可以幫助地球物理學(xué)家繪制地磁的起伏圖。

第二段：

Mr Vaknin’s work at Lachish is the most recent of a series of studies he has performed that were enabled by arsonous ancient kings. The first examined a building destroyed when Jerusalem was burned by Babylonian troops in 586BC. According to the biblical Book of Kings, this happened “in the fifth month, on the seventh day of the month, which was the nineteenth year of King Nebuchadnezzar, King of Babylon”.

瓦克寧在拉吉什的工作是他在古代國王縱火的情況下所進行的一系列研究的最新成果。第一組研究了公元前586年耶路撒冷被巴比倫軍隊燒毀時的一座建筑。根據(jù)圣經(jīng)《列王記》，這件事發(fā)生在“五月，該月的第七天，也就是巴比倫王尼布甲尼撒十九年”。

第三段：

Mr Vaknin says that date is considered reliable by biblical scholars. So he and his colleagues were able to pinpoint the moment when this building, the remains of which were found under a car park, was destroyed. Those remains included pieces of the polished upper floor and the burnt wooden beams that once supported it.

瓦克寧先生說，圣經(jīng)學(xué)者認(rèn)為這個日期是可靠的。所以他和他的同事們能夠確定這座建筑的殘骸在停車場下被摧毀的確切時間。這些殘骸包括拋光的上層地板的碎片和曾經(jīng)支撐它的燒焦的木梁。

第四段：

The fire’s heat would have erased any magnetism in the minerals of this floor. Earth’s magnetic field then left its mark as those minerals cooled, magnetising them anew. Assuming the fragments have not moved since then, the alignments of their magnetic fields will point in the direction of Earth’s field as it was on that fateful day.

火的熱量會抹去地板上礦物的磁性。隨著這些礦物冷卻，地球磁場留下了它的印記，重新磁化它們。假設(shè)這些碎片從那時起就沒有移動過，它們的磁場就會指向地球磁場的方向，就像那災(zāi)難性的一天一樣。

第五段：

Looking for magnetic alignments in this way was well understood when Mr Vaknin began his investigation. But he and his colleagues also did an experiment. They heated samples of the fallen floor in their laboratory and exposed them to a magnetic field as they cooled down, thus repeating what had happened when the edifice was destroyed. By comparing the resultant magnetisation with the original one, and knowing the strength of the field they had themselves applied, they were able to estimate the strength of Earth's magnetic field on the day of the sack.

當(dāng)瓦克寧先生開始他的研究時，以這種方式尋找磁場排列是很容易理解的。但他和他的同事們還做了一個實驗。他們在實驗室里加熱掉下來的地板樣本，并在它們冷卻時將它們暴露在磁場中，從而重復(fù)了大廈被摧毀時發(fā)生的事情。通過將合成的磁化強度與原來的磁化強度進行比較，并了解他們自己施加的磁場強度，他們就能夠估算出在洗劫當(dāng)天地球的磁場強度。

第六段：

They have now repeated this approach at other sites, leading to well-dated reconstructions of the magnetic fields connected with the sackings of Gath, Kinneret, Bethsaida and Ekronin, as well as Lachish and Jerusalem, courtesy of military campaigns by Aramean, Assyrian and Babylonian kings. The dates range from about 830BC to exactly 586BC.

現(xiàn)在，他們在其他地點重復(fù)了這種方法，導(dǎo)致了與迦特、Kinneret、Bethsaida和Ekronin，以及拉吉和耶路撒冷被洗劫有關(guān)的磁場的年代久遠的重建，這些都是由于亞蘭、亞述和巴比倫國王的軍事行動。日期從公元前830年到公元前586年。

第七段：

That is more or less the maximum span for which this approach is feasible. Written accounts of earlier invasions, in the Bible and other texts, are thought insufficiently reliable. And after the Babylonians came the Persians, who were, as Mr Vaknin observes, “kind enough not to destroy cities”.

這或多或少是這種方法可行的最大跨度?！妒ソ?jīng)》和其他文本中關(guān)于早期入侵的書面記載被認(rèn)為不夠可靠。巴比倫人之后是波斯人，正如瓦克寧所言，波斯人“非常善良，不會摧毀城市”。

第八段：

It is, though, an extremely useful span, for it coincides with a hiatus in the archaeological record called the Hallstatt plateau. This “plateau” is a flat stretch of the calibration curve used for a technique called radiocarbon dating. It is a period, from 400-800BC, when, for reasons not entirely clear, radiocarbon dating breaks down.

然而，這是一個非常有用的時間段，因為它正好與考古記錄中被稱為哈爾斯塔特高原的一個空白期相吻合。這個“平臺”是一種被稱為放射性碳年代測定法的校準(zhǔn)曲線的平坦延伸。這是公元前400-800年的一個時期，由于不完全清楚的原因，放射性碳定年法被打破了。

第九段：

Samples from the time of the plateau have hitherto been undatable within that four-century span. This might now change. Radiocarbon dating relies on measuring the amount of 14C, an unstable isotope of carbon, in organic materials such as wood. Thanks to the ingenuity of Mr Vaknin and his colleagues, and the ruthlessness of ancient kings, the magnetisation of inorganic materials that have been exposed to heat, such as shards of pottery from cooking vessels, offers an alternative.

迄今為止，高原時期的樣本還無法確定這四個世紀(jì)的時間跨度。這種情況現(xiàn)在可能會改變。放射性碳年代測定法依賴于測量有機材料(如木材)中碳的一種不穩(wěn)定同位素——14C的含量。多虧了瓦克寧先生和他的同事們的聰明才智，以及古代國王們的冷酷無情，諸如烹飪器皿上的陶瓷碎片等暴露在高溫下的無機材料被磁化，提供了另一種選擇。

第十段：

Mr Vaknin’s data points are also valuable for geophysicists who want to understand how movements in Earth’s core change the planet’s magnetic field. The period Mr Vaknin studies was one in which this field was usually about 50% stronger than it is today, and for short periods was double today’s strength.

對于想要了解地核運動如何改變地球磁場的地球物理學(xué)家來說，瓦克寧先生的數(shù)據(jù)點也很有價值。在瓦克寧研究的時期，這一領(lǐng)域通常比現(xiàn)在強50%，而且在短期內(nèi)是現(xiàn)在的兩倍。

第十一段：

As to Lachish, history did not forget it. Sennacherib celebrated victory by ordering huge alabaster reliefs of his victory (one of which is depicted above) to decorate his palace in Assyria’s capital, Nineveh. They are now in the British Museum.

至于拉吉，歷史沒有忘記它。西拿基立下令用巨大的雪花石膏浮雕來裝飾他在亞述首都尼尼微的宮殿，以此來慶祝勝利。它們現(xiàn)在收藏在大英博物館。