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What is the most powerful thing in the universe? The time. Time can heal the pain, time can smooth the memory, most of all, time can shape the world. 在浩瀚宇宙中，什么是最具有能量的东西？是时间。时间可以抚平伤痛，时间可以让回忆变得美好，最重要的是，时间创造了这一切。

Our entire solar system formed from the debris of dead stars just like other stellar system forming today. There are at least 140 solar systems that had been observed today, and it doesn't seem that the formation process of our solar system is unique in any sense whatsoever.
就像其他所有太阳系一样，我们的太阳系也是由死星残骸形成的。科学家们至今已经观测了至少140个太阳系，但是就形成过程来说，我们的太阳系跟其他的如出一辙。
About 4.5 billion years ago, the cloud of stardust and gas that was to become our solar system began to spin. As the gravity pulled the material into the centre, it heated up. All of a sudden the young Sun ignited. The lighter gas was swept far out into the solar system, leaving heavier and rocky material near the Sun which soon condensed to form rocky planets: Mars furthest from the sun, then the earth, then Venus. At this stage, was there anything different from each other? The answer is not. They are actually very similar. They've all got an iron core, they've all got lighter silicate stuff floating on top. The earth has exactly the same components as the sun and all the other planets except one, we have a large satellite: the Moon.
大约45亿年前，宇宙中的星云跟气体开始旋转，这些物质后来组成了我们的太阳系。当重力将所有物质拉向旋转中心的时候，中心部位的温度开始升高。也就在某个瞬间，年轻的太阳在爆炸中诞生。质量轻的气体被横扫到太阳系边缘，而重的气体跟岩石类物质都留在了太阳周围，而这些物质很快凝缩成了我们今天太阳系里的行星：火星离太阳最远，地球适中，金星最近。在行星刚形成的这个阶段，这三个星球彼此之间有很大差别么？答案是否定的。他们其实非常相似。它们都拥有铁核心，他们也都被硅酸盐气体覆盖。不过除了跟太阳还有其他行星组成成分一样，地球拥有一个巨大的卫星：月球。
How Mars became a cold dead world, how Venus beneath a permanent cloud cover, developed a surface temperature of a molten lead and only on earth are the conditions right for life? Why should the earth have developed so differently from our planetary neighbors?
火星如何变成了一个冰冷的死亡世界？而永远笼罩在厚厚云层下的金星为何表面温度能熔化铅？为何只有地球的条件适合孕育生命？我们如何变得跟我们的邻居截然不同？

4 bllion yeas ago, Mars was warm and wet just like Earth, but it changed later. The cloud was full of clouds of water vapour, from the clouds the rain fell, and streams and rivers formed eroding valleys. The volcanoes on Mars are huge and they grow and grow. They produces a lot of gases including carbon dioxide which get added to the atmosphere. And the carbon dioxide has a decisive effect on the planet's surface temperature. It's so called the green house gas acting like a thermal blanket keeping the plant warm. But today Mars is cold and dry, and there is no sign of running water, what happened? The rain picks up carbon dioxide from the atmosphere and washes it into the lake and surface, and the carbon dioxide would have been replaced by the erupting of volcanoes, and it appeared that this volcanic activity was ceased. Mars is much smaller than Earth and its internal store of heat powering volcanoes was quickly reduced. The distance from the Sun is farther, and eventually the volcanic activity stopped and all of the carbon dioxide in the atmosphere was removed by rains. 3 billion years ago, Mars entered a permanent Ice Age. Its water was locked up below the surface，and it remained frozen till this day.
40亿年前，火星跟地球一样温暖湿润，但是情况后来发生了改变。那时火星的大气里充满了大团大团的水蒸气，雨从这些云雾中落下，落到地上就形成了侵蚀山谷的小溪跟大河。火星原本有很多火山，火山喷发二氧化碳储存在大气中。二氧化碳对星球表面温度的影响十分显著，它是一种温室气体，就像电热毯一样能让整个火星变得温暖。今天我们看到的火星寒冷干燥，而且没有发现液态水的迹象，到底发生了什么？原来降水过程让大气中的二氧化碳被冲刷到地表的湖中，但是并没有火山喷发出的二氧化碳补充道大气里，火星体积比地球小很多，内部的能量很快衰竭，火山活动很快停止，大气中的二氧化碳几乎被迅速被雨水消耗殆尽，加上本身离太阳就很远，所以气温骤降。30亿年前，火星进入了永久冰河期，水被冰层封在了地表之下，一直到今天。
What about Venus which mysterious surface is covered with layer of clouds? It is the same size as earth, so it wouldn't cool down as the smaller Mars did. About three and a half billion years ago, Venus and Earth are not that different, their atmospheres are very similar at this point, but Venus is closer to the Sun and it's warmer. Instead of being a liquid on the surface, the water on Venus exist in the form of water vapour in the atmosphere. Meanwhile the volcanoes are all over the planet, they are pumping a lot of gas into the atmosphere: carbon dioxide. Together with water vapour, carbon dioxide keeps the heat of the Sun in, the surface begins to warm up and the climate became unstable. It was too hot and there is no rains, no rivers, no lakes no seas, no plate tectonics.
那么云雾笼罩下的神秘金星情况怎么样呢？金星跟地球一样大，所以内部能量不会很快耗尽。在35亿年前，与地球并无太大差异，它们的大气层几乎都是一样的只不过金星离太阳更近，所以进行更热。金星的水通常不是液态的，而是水蒸气存在于空气中。同样，金星火山到处都是，二氧化碳喷射的也都到处都是--。加上水蒸气，这些气体让太阳的热量无法散去，气温不断上升，气候开始变得不稳定。这里很热，没有雨水，没有河流，没有湖或者海，没有板块运动。

By contrast what seems to make the earth so special is its extraordinary climatic stability over a long period of time. For example, there's been liquid water on the surface of the planet for nearly four billion years, and it's constantly changing. Earth's surface is made up of a few giant rocky plates, their edges marked by chains of volcanoes, mountain ranges and earthquakes, this system of geological change is called plate tectonics and it has a tremendous effect on maintaining earth's climatic stability. But keeping this astonishing system going over billions of years has required another surprising factor. The shifting orbits of other planets produce a fluctuating gravitational pull on the earth and make the Earth's own tilt shift. These shifts have a major influence on climate, and without the gravity of our satellite Moon to keep the earth's tilt within the narrow limits,these fluctuations could even cause catastrophe worse than any Ice Age. If the moon did go away, there may be no seasons on earth, or one hemisphere would stay light for months while the other dark for months. Every life exists on earth today is because of the protection of the Moon.
对比一下不难发现地球命运如此不同得归功于长期稳定的气候。举个例子，40亿年来地表一直都有液态水。地球表面有几个巨大板块组成，板块边缘都由火山带，巨大山脉与地震带组成，这种地质运动叫做“板块运动”，它对气候的稳定有着举足轻重的作用。地球有着活跃的地质运动：板块运动，而这些分布地表的板块对地球稳定的气候有这事关重要的影响。但是要让这样的地质系统稳定运行数十亿年，还需要另外一个惊奇的因素：其他行星的不断公转对地球的引力波动变化，甚至让地球自己倾斜角度发生改变，而一旦改变对地球气候的影响是决定性的，如果没有月球引力的平衡，一些小的引力波动带来的后果可能是灾难性的甚至比冰河时期还要可怕。如果没有了月球，地球上将没有了四季；或者整个半球数月看不到太阳，同时另外一半球被太阳炙烤数月。地球上今天每个生命的存在，都是因为月球的保护。

Within the first billion years of Earth's history, life appeared in the oceans and began to affect the atmosphere and surface. And this may be the answer to our question, what makes our planet so special is the unique partnership between earth and all living things. The planet activity shapes life, but through the carbon cycle life plays a major role in maintaining earth activity. For example, some of the carbon dioxide come out of the volcanoes would be fixed in plants, if the plants are eaten, some of that carbon dioxide may be breathed out. Rain water may dissolve it, and it will be end up in the ocean, where living things may use it to make their shells. Shells may eventually form new rock deep on the ocean floor. From there it will, in time, be subducted, and perhaps 100 million years from now the carbon dioxide will be erupted again from a volcano to complete this remarkable cycle. For millions of years, this partnership controlled the level of carbon dioxide in our atmosphere, keeping the earth's climate in the narrow zone where water remains liquid neither freezing as on Mars, nor boiling away as on Venus. In turn, liquid water lubricated the motion of the plates, and of course without it, life would be impossible. So every part of this cycle is essential. Life to draw down carbon dioxide, the earth's activity to return it to the atmosphere, and water to keep the whole cycle running. Our world is not just a rock spinning in the universe, instead it's an intricate system where change to one part affect all the others. Everyone is part of this world, the places we go to, the views we see, the people and the animals and flowers and trees we are all familiar with are part of the destiny. And it maybe the explanation why I am telling you all this today.
地球刚诞生的十亿年内，生命出现，并且逐。渐开始影响空气与地表。这也许就是我们的问题的答案了：我们星球为什么这么特别的原因是因为整个星球与生命之间独特的合作关系。地球的一切活动创造了生命，而生命也通过碳循环的过程，维持着地球的活动。比如说一部分从火山喷发的二氧化碳会被锁定在植物里；作物被吃掉了，二氧化碳还是会被呼出来；雨水可以溶解空气中的二氧化碳，最后还是会进入海洋，浮游生物们又用海里的二氧化碳构建自己的壳，而这些壳类物质又在海床上形成新的岩石。从那里，岩石渐渐地又开始“潜没”（地表板块边缘互相挤压并向地心沉没的现象）的过程，也许再过个一亿年，潜没的岩石中的二氧化碳又重新被火山喷发出来，一个伟大的碳循环过程就又完成了。数百万年来，生物与地球的合作维持了大气中二氧化碳含量，让地球的气候保持稳定，所以才没出现火星上冰冻封于地下与金星上烧开了气体这样的情况。有了液态水，地球板块运动就像有了润滑剂，当然也就有了生命。这个循环里的每个环节都是必要的，生命吸收二氧化碳，地球活动重新放二氧化碳到大气中，水保证了整个循环的顺利运转。我们生活的这个世界，绝不是宇宙中的一个会旋转的大石头，相反它是个前一发动全身的复杂系统。我们每个人都是这个世界中的一个环节，我们要去的地方，我们看到的风景，我们熟悉的人，动物，花草，树木也都是命运中的小小零件

Please go outside and take a close look at the dirt we stand on, the sky we walk beneath, the air we are breathing, the planet we all live on, our ancient astonishing living home.
请走出房间，仔细地看看我们站立的土地，头顶的苍穹。我们生活的这个星球，是我们古老悠久，令人称奇，鲜活生动的家园。

冷知识专家为你总结：为什么我们的地球这么特别？
地球气候一直非常稳定，40亿年来地表都有液态水。地球有着活跃的地质运动：板块运动，而这些分布地表的板块对地球稳定的气候有这事关重要的影响。火山喷发的二氧化碳被雨水带到地表，被岩石吸收后沉积海底，随着板块挤压，这些含有二氧化碳的岩石被潜没到地下越来越深的地方加热，然后随着岩浆再次喷发到地表，释放大量二氧化碳，这就是地球地质的循环现象。
地球有巨大卫星月球，这对地球自转稳定性起了决定性作用。如果没有月球的引力，地球会受到全太阳系任何星球引力的作用，从而自转轴会随机地偏转。这意味着地球可能没有了四季，气候极其不稳定：在一天之内有可能经历酷暑与极寒；或者整个半球整月整月的没有阳光，而另一半球却被太阳连续炙烤几个月。

太阳现在比刚出生时热了30%，但是为什么地球未受影响？绝大多数能锁住二氧化碳岩石都在石灰岩或者木炭这类的沉积层中，这些东西都是由远古时期的海床中的浮游生物沉积形成的。浮游生物使用大气中的二氧化碳来生长自己的外壳，它们不停地吸收二氧化碳，为地球降温做出了巨大贡献。所以在很久以前的某个时间，地球上出现了生物，并在阳光能量增加的情况下快速繁殖，越来越多的生物加入到了吸收二氧化碳的队伍中，进一步减弱温室效应。
地球内部能量驱动的地质运动与生物不停地的代谢活动，合作了这一场完美的循环过程，让地球远离二氧化碳的积累，让气候保持稳定，让液态水的存在更加稳定。而液态水是板块运动的润滑剂，没有板块运动，生命也不能孕育。
火星原本有很多火山，火山喷发二氧化碳储存在大气中让火星温暖潮湿，但是降水过程让大气中的二氧化碳永久被锁定在岩石中，加上火星体积比地球小很多，火山活动很快停止，大气中的二氧化碳几乎被迅速消耗殆尽，所以气温骤降，进入冰冻期。
金星跟地球一样大，在35亿年前，与地球并无太大差异。但是由于它离太阳更近，表面温度更高，所以并没有那么多液态水把大气中的二氧化碳冲下来侵蚀岩石，被岩石吸收，加上它不像火星那么小，火山不会一会就喷发完，所以大气中的二氧化碳越来越多，恶性循环，地表温度越来越高，液态水越来越少。没有海洋的金星，含二氧化碳的岩石也无法潜没到其他岩层下方，自然不可能有板块运动。

Fun Facts Dictionary《冷辞海》
1.Earth is the third planet from the Sun, the densest planet in the Solar System, the largest of the Solar System's four terrestrial planets, and the only astronomical object known to harbor life.
我们的地球是离太阳第三近的行星，是太阳系中密度最大的星球，四个类地行星中体积最大的，也是目前唯一已知孕育生命的星球。

2.Earth formed about 4.54 billion years ago. The Moon is the Earth's only permanent natural satellite; their gravitational interaction causes ocean tides, stabilizes the orientation of Earth's rotational axis, and gradually slows Earth's rotational rate.
地球形成于45.4亿年前。月球是地球唯一的自然卫星。我们熟知的潮汐现象是因为地月之间的引力相互作用。月球的引力还让地球自转更加稳定，并且让自转变的平缓。

3.The sun will stop igniting in 5 billion years. 太阳将在50亿年以后熄灭。


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