英语听力：自然百科 地球力场 Earth's Force Field—9

 As the vast sphere reaches / maximum speed, something incredible happens. Huge lines of magnetism¹ arc in and out of the model core. 

Well, we can't see the magnetic field coming out of the experiment, we can measure them, we can put many different magnetic field sensors², and then map out these magnetic fields were coming out, rotating, changing. It's fantastic. 

 

Interactions between the inner and outer core create what's known as a dynamo. This generates a powerful, stable and self-sustaining magnetic field. This is showing magnetic field patterns: red coming out of the experiment, blue going into the experiment,  nothing like I imagine that would be.

 

Lathrop's mechanical core supports the theory that Earth's magnetic field is produced by a geodynamo in its interior. The motion of liquid metal in the outer core is vital to this process. The geodynamo depends on the flow of hot molten metal in the Earth's core. Does Mars' cold core explain how it lost its magnetic shield? Could the Earth suffer the same fate as Mars? 

 

So, / cooling is gonna continue and eventually the Earth's solid inner core is gonna grow larger, larger, and larger. At some point, it may solidify³ completely, and it's possible that even before it solidifies⁴ completely, the Earth's magnetic field will shut off.

 

Is the South Atlantic Anomaly a sign that the Earth's core is cooling? Lathrop doesn’t think so.

 

People think about the Earth's magnetic field as just being North, South, right? You have a compass, it points North. Everything is simple. But if you look carefully on maps, you notice that magnetic North and geographic⁵ North are not the same thing. That's in part because magnetic pole is actually in Canada. 

 

The magnetic North Pole is illusive⁶. Whenever explorers look for it, they find it in a different place.

1 magnetism   

n.磁性，吸引力，磁学

参考例句：

• We know about magnetism by the way magnets act.我们通过磁铁的作用知道磁性是怎么一回事。
• His success showed his magnetism of courage and devotion.他的成功表现了他的胆量和热诚的魅力。

2 sensors   

n.传感器，灵敏元件( sensor的名词复数 )

参考例句：

• There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
• Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时，有很大变化。 来自辞典例句

3 solidify   

v.(使)凝固，(使)固化，(使)团结

参考例句：

• Opinion on this question began to solidify.对这个问题的意见开始具体化了。
• Water will solidify into ice if you freeze it.水冷冻会结冰。

4 solidifies   

（使）成为固体，（使）变硬，（使）变得坚固( solidify的第三人称单数 )； 使团结一致； 充实，巩固； 具体化

参考例句：

• Jelly solidifies as it gets cold. 肉冻冷却就凝固。
• It is stirred with 10%sodium carbonate solution(50ml)and then with water (50ml), after which It'solidifies. 与10％碳酸钠溶液（50毫升）混合搅拌，然后再用50毫升水混合搅拌，从而析出固体。

5 geographic   

adj.地理学的，地理的

参考例句：

• The city's success owes much to its geographic position. 这座城市的成功很大程度上归功于它的地理位置。 来自《简明英汉词典》
• Environmental problems pay no heed to these geographic lines. 环境问题并不理会这些地理界限。 来自英汉非文学 - 环境法 - 环境法

6 illusive   

adj.迷惑人的，错觉的

参考例句：

• I don't wanna hear too much illusive words.我不想听太多虚假的承诺。
• We refuse to partake in the production of illusive advertisements.本公司拒绝承做虚假广告。