2015-05-06 BBC:星光七纪元-31

 And with his colleagues, he did the calculations to prove it. The key was the conditions created in the final stages about massive stars fighting against its gravity. These stars are so massive and hot that they can go through a whole series of nuclear reactions. The ashes of one set of nuclear reactions becomes the fuel for the next set of nuclear reactions. The most massive stars are able to fuse heavier and heavier elements in the series of layers, creating the energy to resist the relentless¹ inward pull of gravity. There is neon and magnesium² and more oxygen, then the silicon³ and sulphur, and finally, in the middle, a core of Iron. And that’s where the fusion⁴ starts. With fusion at an end, there is no more energy to fight back. And gravity wins the battle. The star is doomed⁵. When that ball of iron, which is a certain critical mass, about the size of the earth but much, much more massive, the electron pressure is no longer able to support it against the inward force of gravity, so it starts to collapse⁶. It collapses⁷ to a ball, about the size of a city and then rebounds⁸, and that rebounce hits the surrounding layers, launching a supernovae explosion. It’s the speed and violence of the collapse of the star’s iron core that triggers the supernovae.

1 relentless   

adj.残酷的，不留情的，无怜悯心的

参考例句：

• The traffic noise is relentless.交通车辆的噪音一刻也不停止。
• Their training has to be relentless.他们的训练必须是无情的。

2 magnesium   

n.镁

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The water contains high amounts of magnesium.这水含有大量的镁。

3 silicon   

n.硅(旧名矽)

参考例句：

• This company pioneered the use of silicon chip.这家公司开创了使用硅片的方法。
• A chip is a piece of silicon about the size of a postage stamp.芯片就是一枚邮票大小的硅片。

4 fusion   

n.溶化；熔解；熔化状态，熔和；熔接

参考例句：

• Brass is formed by the fusion of copper and zinc. 黄铜是通过铜和锌的熔合而成的。
• This alloy is formed by the fusion of two types of metal.这种合金是用两种金属熔合而成的。

5 doomed   

命定的

参考例句：

• The court doomed the accused to a long term of imprisonment. 法庭判处被告长期监禁。
• A country ruled by an iron hand is doomed to suffer. 被铁腕人物统治的国家定会遭受不幸的。

6 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

7 collapses   

折叠( collapse的第三人称单数 )； 倒塌； 崩溃； （尤指工作劳累后）坐下

参考例句：

• This bridge table collapses. 这张桥牌桌子能折叠。
• Once Russia collapses, the last chance to stop Hitler will be gone. 一旦俄国垮台，抑止希特勒的最后机会就没有了。

8 rebounds   

反弹球( rebound的名词复数 )； 回弹球； 抢断篮板球； 复兴

参考例句：

• V is the velocity after the gas particle rebounds from the wall. V是粒子从壁上弹开后的速度。
• In the former case, the first body rebounds with practically its original velocity. 在前一种情况下，第一个物体实际上以原来的速度弹回。