听力文本

Chapter one in our particular case
第一章，生物起源
takes us back to 4.5 million years.
要将我们带回450万年前
to when the earth was really quite young.
当时的地球，初生不久
Exactly what triggered life here is still a mystery
生命的起源至今仍是未解之谜
but there are several theories.
但也有不少理论
The most common one is that life began purely by accident.
最常见的理论认为生命的起源完全是巧合
In pools of primodial soup,
起源于原始汤的水池里
full of chemicals called amino acids
富含名为氨基酸的化学物质

These molecules would have collided at random for millions of years
数百万年来，这些分子不断地随机碰撞
until the perfect combination just happened
直到一次完美地化合反应发生
the ultimate lucky break that started the chain of life.
这次幸运之极的碰撞，开启了生物起源之门
It is extremely unlikely that life could spontaneously create itself.
生命的自发产生，乍看之下让人难以置信
But I don't think that's a problem with this theory.
但在这一理论中，这却并非不可能之事
It's like winning a lottery.
就像是中彩票
with the odds are astro-nomical most weeks someone hits the jackpot.
虽然概率微小，但几乎每周都有人中头彩
But there is another intriguing idea called "panspermia,"
另一种有趣的理论，被称为"有生源说"
which says that life could have originated somewhere else ..
称生命可能起源于其它地方
and it's been spread from planet to planet
被传播到各个行星
by asteroids.
载体就是小行星
It seems possible that lumps of rock could carry frozen organisms inside them
小行星内部似乎可以携带被冰冻的微生物
organisms able to with stand extremes of temperature and the vacuum of space.
能够忍受极端的温度和真空条件的微生物
If so, asteroids could even now
若真如此，小行星现在依然
be transporting life to other worlds.
能够作为行星间生物传播的载体
Regardless of which theory is right,
无论哪一种理论是对的
once life begins, the next chapter starts.
生命一旦出现，我们便进入了下一章
That's all about survival.
物竞天择，适者生存
survival links you me and ET
它将你我还有外星人联系在一起
and it generates rules all of its own.
并且演变出了一套自己的法则
Survival demands a source of energy what we call food,
生存需要能量，即食物来维持
or else it would grind to a halt.
否则生命便会慢慢消亡
Once nourished, life can then copy itself to
一旦有了养料，生物便开始了繁殖
protect against the death of any one individual.
来抵御种族的灭亡
Ultimately, that leads to evolution
最终，这导致了进化
evolution that would happen even on alien worlds,
这种进化即使在其它星球同样可能发生
producing, in some instances,
在某些情形下
animals that I think we would recognize as being alive,
产生的动物我认为我们可以称之为生命
even if they look a bit strange.
即便它们看起来有些奇怪

视频及简介

《与霍金一起了解宇宙》纪录片耗时3年多制作，期间霍金曾多次坚持对剧本作大幅修改。霍金指出外星生物在消耗尽自己星球上的资源后便会乘坐大型飞船到他们能够到达的星球掠夺资源，并将那里开拓成为他们的殖民地；如果有外星生物到访地球，那将会像当年意大利航海家哥伦布登陆美洲大陆一样，最后给人类带来毁灭性的灾难。

重点讲解

重点讲解：
1.by accident 偶然地；意外；不小心
例句：I found out the secret of the matter by accident.
我偶然发现了那件事情的秘密。

2.at random 随便地；随机地
例句：The children sat around the table at random.
小孩们随便的围坐在桌子旁边。

3.with the odds 可能性
例句：Even with the odds of detecting dark matter not in their favor, astrophysicists maintain an unwavering optimism.
对于天体物理学家们来说，尽管发现暗物质的可能性并不大，但他们一贯保持着乐观的态度。

4.grind to a halt 慢慢停下来；慢慢停止
例句：Every thirty seconds, the server experiences a huge storm of disk-writing activity, causing the system to nearly grind to a halt.
每隔30秒，服务器就会遇到磁盘写活动高峰，导致系统几乎陷于停顿。