我们以科学为指引，试图重建恐龙的最后时刻。

　　The first effect was the impact itself.

　　第一个效果是撞击本身。

　　So when a 10-kilometer diameter asteroid enters through the atmosphere and impacts the surface of the earth,

　　当一颗直径10千米的小行星，进入大气层，并且撞击到地球表面时，

　　you have to realize that 10-kilometer object is comparable to the size, the height scale of the atmosphere itself.

　　你得知道那个10千米的物体在尺寸上基本与大气层本身的高度相当。

　　And so the object almost effectively never even sees the atmosphere.

　　所以这东西基本就没受大气影响。

　　At that time, a 10-kilometre impactor is going to vaporize, melt and displace something like well over 10,000 cubic kilometers of the surface of the earth.

　　那时，这10千米的撞击物将要使地球表面上超过一万立方千米的东西被蒸发、融化和被撞飞。

　　You've got 10,000 cubic kilometers of limestone and evaporate and granite being vaporized and excavated and thrown around the planet.

　　一万立方千米的石灰岩和大理石被蒸发汽化，或是被从地球上抛出。

　　It's a hideously violent event the impact of an object of that size.

　　那个尺寸的物体的撞击是一个极其暴力的事件。

　　The initial impact would have instantaneously vaporized nearly 73 billion tons of solid rock.

　　撞击的一瞬间会立刻蒸发掉近七百三十亿吨坚硬的坚硬岩石。

　　You would be able to hear this blast around the world, probably multiple times going around it.

　　全世界都能听到这个轰鸣，可能会环绕地球多次。

　　We know from human history that when Krakatoa, the great eruption occurred in Indonesia, that people heard it in the mainland and other parts of Eurasia,

　　我们知道在人类历史上，印度尼西亚的喀拉喀托火山大爆发时，印度尼西亚主岛和欧亚大陆其它地方的人们都能听到，

　　and it certainly was detected by barometers all the way around the world.

　　而且全世界范围内的气压表都能探测得到。

　　This is something far larger, so you could probably hear this all the way around the world.

　　而这是比火山爆发大得多的事情，所以很可能在全球各地都能听到。

　　There may have even been noticeable earthquakes, spreading out from it around the world.

　　可能还会有明显的地震，从撞击地点传到世界各地。

　　And then things would begin to get really weird.

　　之后的事情会变得非常奇怪。

　　The impact of the asteroid striking the sea would set off another form of destruction - tidal waves.

　　小行星撞击到大海会引发另一种破坏方式——海啸。

　　These tsunamis would have been over 3 miles high!

　　这些大海啸高度可达3英里！

　　At the time of the impact, the impact site itself was under a shallow sea of a couple hundred feet deep and so very naturally,

　　在撞击的同时，撞击地点本身就是在几百英尺深的浅海下面，所以很自然，

　　one of the immediate effects of the impact itself was to launch an enormous Tsunami.

　　撞击的一个直接效果就是引发极剧烈的海啸。

　　This is unlike any Tsunami any human has ever witnessed.

　　这种海啸从没有人见过。

　　We're talking kilometers height of water moving across the what was then the early Gulf of Mexico.

　　海浪的高度达几千米从那时早期的墨西哥湾穿过。

　　After the initial impact, shockwaves and tsunamis, things began to really heat up.

　　在最初的冲击，冲击波和海啸之后，便真正开始升温。

　　The upper atmosphere would heat to maybe 1,200,1,500 degrees, hotter than the elements in your oven on self-clean.

　　上层大气被加热到1200到1500度，比家里烤箱自洁时的电热元件温度都高。

　　Another way of looking at it is that 20% of 100 million megatons is 20 million megatons, which amounts to 1 megaton hydrogen bomb at 6 kilometer intervals all around the planet.

　　看待这个问题的另一种方法是，一亿兆吨的百分之二十即两千万兆吨，这相当于在整个地球上每隔6千米放1百万吨氢弹。

　　The heat from the upper atmosphere would've ignited fires everywhere that fuel was available.

　　上层大气层的热量会在所有有燃料地方引发的火灾。

　　And the quantity of energy probably hit several thousand degrees on the surface for several hours, hot enough to melt steel.

　　其热量可能达到让表面温度几小时内都是几千度，足够融化钢铁。

　　The vaporized material blown out of the crater, in this big expanding fireball, if you will, that was hundreds of kilometers across, is glowing and is as hot as the sun.

　　被抛出陨石坑的被蒸发的物质，在这个不断扩大的直径几百千米的火球里，闪耀着像太阳般炽热。

　　So you've got these little millimeter and dust size little beads of glassy material recondensing, from that vaporized rock,

　　所以这些几毫米灰尘大小的玻璃材质的小珠子，岩石蒸气在其表面上再凝结，

　　raining back through the atmosphere all across the entire planet, tens and tens of billions of tons of this stuff.

　　穿过大气层雨滴般落下在整个地球上，这个东西有数十亿。

　　The combined effect of all these trillions upon trillions of reentering meteorites heated, shock heated the upper atmosphere to the point

　　所有这些千万亿重新进入的陨石结合在一起的影响是，加热了，冲击波加热了上层大气层到达一定温度，

　　that we all standing on the surface of the earth looking up it, for all the world would like the, the whole atmosphere had been turned into a pizza oven.

　　我们站在地球表面抬头看它，因为整个世界就像是，整个大气层变成了披萨炉。

　　For those animals and plants which survived the initial impact, fires and darkness, the asteroid impact had one more deadly gift - a chemical assault.

　　对于那些从最初的撞击、大火和黑暗中幸免的动物和植物，小行星撞击还有一个更致命的礼物——化学攻击。

　　If you had to choose the worst possible place on earth for an asteroid to strike, it would have been the exact spot where the Baptistina asteroid struck in the Yucatan.

　　如果必须选择在地球上小行星撞击最糟糕的地方，那就是巴蒂斯缇娜小行星在尤卡坦的撞击地点。

　　Because lying beneath the seafloor, directly under the spot where the asteroid struck, were layers upon layers of anhydrite and limestone.

　　因为在海床的底下，小行星撞击地点的正下方，是一层一层的硬石膏和石灰石。

　　Now normally these minerals are perfectly harmless.

　　这些矿物质通常完全无害。

　　But something very nasty happens when you add intense heat and pressure and mix that with water.

　　当你对其施加很大的热量和压力并加之以水的话，就会发生很危险的事情。

　　And trust me, a 100 million megaton explosion cause a heck of a lot of heat and a huge amount of pressure.

　　相信我，一个一亿兆吨当量的爆炸会产生非常多的热量和大量的压力。

　　The end result was an acid that rained down on the world.

　　最终结果就是在世界各地落下酸雨。

　　Those materials are very bad to impact into, because when you vaporize and distribute the vapor from those particular rocks, you turn the carbonate-containing limestone into greenhouse warming CO2, carbon dioxide.

　　那些物质在撞击时非常危险，因为那些特殊石头会被汽化蒸发并且散播到全世界，这就把含碳的石灰石变成了温室气体，二氧化碳。

　　You turn the sulfate containing evaporate into sulfuric acid aerosols in the atmosphere.

　　把含硫的蒸汽在空气中变成硫酸气溶胶。

　　But then that sulfate acid aerosol tends to want to rain out of the atmosphere over time, and you've got this sulfuric acid rain, dripping all over the landscape.

　　之后硫酸气溶胶随时间从大气中变成液滴落下，所以就会有硫酸雨落到各种地形地貌上。