Magnetic mysteries of Earth's Core
The magnetic field emanating from Earth's core helps create the Northern Lights
* Jules Verne (1828-1905), 法國小說家, 現代科學幻想小說的奠基人
Molten metal
熔融金屬
東京Kei Hirose教授的技術研究所
但是，地震學已使科學家感覺進入行星的核心方向是正確的。大地震震動時從地球的一側到其他地方所產生的地震波，讓科學家們建立一個內部的圖形。
This core is as large as Mars. But - like a planetary Russian doll - another core was found within this one. An inner-core - a solid metal ball almost the size of the Moon.
Crystal
地球的磁場在過去的 180年已經穩步的減弱了。還有一個區塊比任何其他地方弱化的速度更快。它被科學家們稱為“南大西洋異常”的一個地區，它位於南大西洋和南美洲的中心。
這已知會危害航空器，因為它在場域裡創建了一個浸染地，使帶電粒子進入軌道衛星和擾亂他們的電子產品和儀器儀表。
該磁極可以漫步例如到赤道，並伴隨壯觀的北極光。它會不會出於特徵之外 - 轉移流動的核心以前扭轉地球磁場數百次。
“如果地球是要扭轉磁場，這不是一個問題是，但是什麼時候，”Lathrop說：。這可能仍然是核心的許多保留的奧秘之ㄧ。但經過幾個世紀的炒作，科學家們終於開始認識到躺在我們腳下6000公里這個偉大的奇蹟。
地平線：核心是在BBC TWO 21:00 BST8月31日 （星期三）播出。
Source: By Gaby Hornsby BBC Horizon31 August 2011 Last updated at 00:45 GMT
從地球核心所產生的磁場幫助北極光的創建
Earthquakes, explosions and observations of Earth's ever-changing magnetic field are helping scientists open up a new window on the heart of our planet.
When Jules Verne wrote A Journey to the Centre of the Earth over 100 years ago, he imagined a place of glowing crystals and a turbulent sea, complete with prehistoric animals and giant mushrooms.
100多年以前當Jules Verne所寫的一部著作"到地球中心的旅行"，他想像他到了一個發光的水晶叢和波濤洶湧的大海，還有史前動物和巨型蘑菇在其中。
* Jules Verne (1828-1905), 法國小說家, 現代科學幻想小說的奠基人
What was actually beneath our feet was a complete enigma. Even to this day scientists astonishingly know more about the rings of Saturn than they do about the core of our own planet.
我們地底下的世界確實是個謎團。即使到了今天的科學家驚人的對土星環的知識比他們了解我們自己的星球核心甚多。
But that is beginning to change. "We're at a golden age in terms of the real discovery of the bulk of the deep Earth," says seismologist Professor Rick Aster.
And remarkably, not everything Verne imagined was wrong.
但是，這已開始改變。 “我們真實大量的發現地球深部在這方面正處於一個黃金時期”地震學家 Rick Aster 教授說。
而且值得注意的是，Verne所想像的並非一切是錯誤。
而且值得注意的是，Verne所想像的並非一切是錯誤。
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多方探索
Wanting to discover the truth about the centre of our world is as basic a human urge as wondering what is on the Moon, although the latter has proved far easier to explore.
想要探索有關我們地球世界中心的事實是身為人類想知道的基本要求就好像我們想知道月球上有什麼，儘管後者已被證明更容易探索。
But scientists are also fascinated by the Earth's core because it is responsible for creating our planet's magnetic field which is vital to life.
As a tool for navigation, it helps honey bees find their hive, while sea turtles, birds and butterflies use it to migrate over long distances.
但科學家們也著迷於地球的核心，因為它負責創建我們的地球磁場是非常重要的生命。
作為導航工具，它有助於蜜蜂找到自己的蜂巢，而海龜，鳥類和蝴蝶使用它來進行長距離的遷移活動。
作為導航工具，它有助於蜜蜂找到自己的蜂巢，而海龜，鳥類和蝴蝶使用它來進行長距離的遷移活動。
The magnetic field also acts as a protective barrier between us and some of the dangers of space, shielding us from radiation in the solar wind.
Physically travelling to the core has proved a non-starter though, because of the rapidly increasing pressures and temperatures.
Even with remote drilling, the deepest we have managed to penetrate is 12km at the Kola Superdeep Borehole in Russia
磁場還可以作為一個讓我們與一些危險的空間隔離保護屏障，做為我們阻擋太陽風的輻射屏蔽。
由於迅速增加的壓力和溫度，按自然規律前往核心被證明無法實現，。
即使運用遙控的鑽孔，在俄羅斯科拉我們已經成功地滲透穿越超深12公里 鑽孔-到地球中心距離只有極少的0.2％。
由於迅速增加的壓力和溫度，按自然規律前往核心被證明無法實現，。
即使運用遙控的鑽孔，在俄羅斯科拉我們已經成功地滲透穿越超深
Molten metal
熔融金屬
We may have very big crystals at the centre of the Earth, maybe up to 10km ”
我們地球中心可能有非常大的晶體，也許長達 10km“
Professor Kei HiroseTokyo Institute of Technology
東京Kei Hirose教授的技術研究所
But seismology has allowed scientists to sense right into the core of the planet. The seismic waves generated during major earthquakes travel from one side of the Earth to the other, allowing scientists to build up a picture of the interior.
Seismology is "the killer application", says Aster, showing us the Earth has a molten outer-core, "an enormous ocean of white hot molten metal that's almost as runny as water".
但是，地震學已使科學家感覺進入行星的核心方向是正確的。大地震震動時從地球的一側到其他地方所產生的地震波，讓科學家們建立一個內部的圖形。
地震學是“應用級殺手”，Aster說，向我們展示了地球外有一個熔化的核心，“一個巨大的白色熱熔融金屬海洋的幾乎像水一樣流動”。
This core is as large as Mars. But - like a planetary Russian doll - another core was found within this one. An inner-core - a solid metal ball almost the size of the Moon.
Scientists believe the solid inner core is made of an iron-nickel alloy.
To understand what form it might take under the extreme conditions at the centre of the Earth, Professor Kei Hirose set himself a seemingly impossible challenge: recreate the conditions of the core in his lab at the SPring-8 synchrotron near Osaka , Japan
這個核心像火星一樣大。但是 - 像俄羅斯娃娃行星 - 在這一個被發現的另一個核心。一個內在核心 - 大小差不多像月球一樣的一個堅實的金屬球。
科學家認為，固態內核是由鐵鎳合金所組成。
要理解它從地球中心極端條件下可能採取何種形式，廣瀨 箕教授給自己定了一個看似不可能的挑戰：在靠近日本大阪，他的實驗室裡使用SPring-8同步加速器重建條件的核心。經過 10年的努力，他終於成功了。
科學家認為，固態內核是由鐵鎳合金所組成。
要理解它從地球中心極端條件下可能採取何種形式，
** 8GeV的超級光子環”，即輸出功率8千兆電子伏
日本Spring-8與美國阿貢國家實驗室的先進光子源APS（Advanced Photon Source，Argone）、法國格勒諾布爾的歐洲同步輻射光源ESRF（Europe Synchrotron Radiation Facility，Grenoble）同為世界三大高能（電子束能量超過5G eV）大型同步輻射設施。
水晶森林
Extreme conditions found at the Earth's core have been recreated in the laboratory
He has created an incredibly powerful vice using the tips of two diamonds. Between them he has pressurised a sample of iron-nickel to three million times atmospheric pressure and heated the sample to about 4,500C .
Under these extraordinary conditions, the crystal structure of iron-nickel alloy changed and the crystals rapidly grew in size. "We may have very big crystals at the centre of the Earth, maybe up to 10km ," says Hirose.
出現在地球的核心極端情境已經在實驗室中重現
他使用兩顆鑽石技巧創造了一個令人難以置信的強大替代品。在他們之間，他對鐵鎳制的樣本以300萬次的大氣壓力加壓和將樣品加熱約4500 C 。
在這種特殊條件下，鐵鎳合金的晶體結構改變，在尺寸上迅速成長。 “我們在地球的中心可能有非常大的晶體，可能高達10公里 ，”廣瀨說。
他使用兩顆鑽石技巧創造了一個令人難以置信的強大替代品。在他們之間，他對鐵鎳制的樣本以300萬次的大氣壓力加壓和將樣品加熱約
在這種特殊條件下，鐵鎳合金的晶體結構改變，在尺寸上迅速成長。 “我們在地球的中心可能有非常大的晶體，可能高達
These crystals would all align "like a forest", says Hirose, pointing at the poles.
The bulk of the Earth's magnetic field is generated not in the inner-core but in the molten metal of the outer-core. This acts as a massive electromagnetic dynamo powered by the Earth's rotation and the long-term cooling of the planet.
But although the basic principle is understood, the details of how the molten metal moves are a mystery. As Earth rotates and loses heat from the centre, complex patterns of flow are created within this vast ocean.
這些晶體都會對齊“像座森林”，廣瀨指著極點說。
地球的磁場大容量產生不是在地球內的核心，而是在熔融金屬的外核。這作為一個龐大的電磁發電機供電由地球的自轉和長期冷卻地球產生的。
不過，儘管基本原則能理解，如何熔融金屬的動作細節是一個謎。隨著地球旋轉，從中心失去熱量，複雜的區塊內的流動創建這個龐大的海洋。
"You might think of the core like the atmosphere of the Earth, being a very restless place with storms and fronts and bad weather," says geophysicist Professor Dan Lathrop from the University of Maryland
“你可能認為核心，如地球的大氣，是一個帶著風暴和鋒面，惡劣天氣等非常不安的地方，” 馬里蘭大學地球物理學家Dan Lathrop教授說：。他自己搭建一個龐大的核心模型，以幫助解釋一些場域裡奇怪的現象 - 這從來沒有固定的，而是不斷波動。
The Earth's magnetic field has been steadily weakening over the past 180 years. And there is one patch that is weakening faster than any other. It is an area scientists have dubbed the "South Atlantic Anomaly", which sits over the South Atlantic and the centre of South America .
It is a known hazard for spacecraft because it creates a dip in the field, allowing charged particles into the orbit of satellites and upsetting their electronics and instrumentation.
地球的磁場在過去的 180年已經穩步的減弱了。還有一個區塊比任何其他地方弱化的速度更快。它被科學家們稱為“南大西洋異常”的一個地區，它位於南大西洋和南美洲的中心。
這已知會危害航空器，因為它在場域裡創建了一個浸染地，使帶電粒子進入軌道衛星和擾亂他們的電子產品和儀器儀表。
Magnetic flip
Scientists have mapped the growth of a weak zone in the Earth's magnetic field
But what some scientists suspect is that it could be much more than an inconvenience to satellite operators - it could be the first indication of a profound change in Earth's magnetic field.
When scientists mapped the Earth's magnetic field down to the level of the outer-core, they discovered that under the South Atlantic Anomaly the simple north-south divide we know at the surface had broken down. There are patches where the field has actually flipped and points north instead of south.
科學家們繪製出地球磁場弱化區域的增長率
但一些科學家懷疑的是，它可能比衛星操作干擾更多 - 它可能是地球的磁場一場深刻的變革第一個跡象。
當科學家們繪製出地球磁場的弱化比外為核心磁場更低，他們發現，在南大西洋異常簡單的南北分裂，我們知道在表面已破裂。場域有地區實際上已經在翻轉和且指向北方，而不是南方。
但一些科學家懷疑的是，它可能比衛星操作干擾更多 - 它可能是地球的磁場一場深刻的變革第一個跡象。
當科學家們繪製出地球磁場的弱化比外為核心磁場更低，他們發現，在南大西洋異常簡單的南北分裂，我們知道在表面已破裂。場域有地區實際上已經在翻轉和且指向北方，而不是南方。
Using his weather analogy, Lathrop believes "a particularly violent or unusual patch of weather" in the molten metal of the outer-core is responsible for reversing the field.
If these patches continue to deepen and spread, the entire Earth's magnetic field could reach a tipping point and flip, he believes.
It is not something that would happen overnight - it could take thousands of years, during which period the field would be pretty confused.
用他的天氣比喻，Lathrop認為“特別爆烈或不尋常的天氣異常區塊”，在熔融金屬的外核是負責扭轉場域。
如果這些區域繼續深化和蔓延，整個地球的磁場可能會達到一個臨界點且翻轉，他認為。
這將不是一夕之間造成的事 - 這可能需要數千年，在此期間，該領域將是非常混亂。
這將不是一夕之間造成的事 - 這可能需要數千年，在此期間，該領域將是非常混亂。
The magnetic poles could wander to the equator for example, and take with them the spectacular Northern Lights. It would not be out of character - the shifting flows of the core have reversed Earth's field hundreds of times before.
"It's not a question of if the Earth is going to reverse the magnetic field, but when," says Lathrop.
Exactly when this might be remains one of the core's many mysteries. But after centuries of speculation, scientists are finally beginning to understand this great wonder lying 6,000km beneath our feet.
該磁極可以漫步例如到赤道，並伴隨壯觀的北極光。它會不會出於特徵之外 - 轉移流動的核心以前扭轉地球磁場數百次。
“如果地球是要扭轉磁場，這不是一個問題是，但是什麼時候，”Lathrop說：。這可能仍然是核心的許多保留的奧秘之ㄧ。但經過幾個世紀的炒作，科學家們終於開始認識到躺在我們腳下6000公里這個偉大的奇蹟。
Horizon: The Core is on BBC Two at 21:00 BST on Wednesday 31 August. Watch more clips or catch up afterwards via iPlayer.
地平線：核心是在BBC TWO 21:00 BST
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