(单词翻译:单击)
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感谢Brilliant对本期节目的支持！前往Brilliant.org/SciShow了解更多。
At 8,848 meters above sea level, Mount Everest reaches further into the sky than any other peak on our planet.
珠穆朗玛峰海拔8848米，是地球上海拔最高的山峰。
It's often called the "roof of the world," but it might also be pretty close to the ceiling—the upper limit of mountain height.
它通常被称为“世界屋脊”，但它也可能非常接近“天花板”——山脉高度的上限。
See, a mountain can't just rise indefinitely. There are limits. Much of this has to do with how mountains form.
一座山的高度不可能无限期的上升。它们的高度也是有限度的。其限度很大程度上与山脉的形成有关。
Most major mountain ranges come about where two segments of Earth's crust are crashing slowly into each other.
大多数主要的山脉都发生在地壳两段缓慢地相互碰撞的地方。
Though the Earth's crust is solid rock, it still changes shape under enough pressure.
虽然地壳是坚固的岩石，但在足够的压力下它也会变形。
And when rock pushes up against rock, you end up with what's called crustal shortening as the plates squish together,
当岩石相互挤压时，随着板块挤压在一起，你最终会得到所谓的地壳缩短；
and crustal thickening as the crust bunches and bulges like a carpet pushed against a wall.
随着地壳的聚集和隆起，也会造成地壳增厚，就像地毯被推到墙上。
This can gradually push parts of a plate kilometers into the air, forming mountains through what geologists call uplift.
这可以将一个板块的某些部分推到几千米的空中，通过地质学家所说的隆起从而形成山脉。
Mount Everest and the surrounding Himalayas are the result of a particularly forceful collision
珠穆朗玛峰和周围的喜马拉雅山脉就是现在的印度
between what is now India and the rest of Asia, which created a lot of uplift.
和亚洲其他地区之间特别强烈的碰撞的结果，碰撞造成了很多隆起。
But, like with everything on this planet, gravity ultimately gets the final say.
但是，就像这个星球上的所有事物一样，重力拥有最终决定权。
Mountains are really heavy, and that mass causes the underlying crust to bend and sag like a person sitting on a trampoline, which lowers the peak somewhat.
山脉真的很重，这样的质量会导致地壳弯曲和下垂，就像一个人坐在蹦床上一样，这在一定程度上降低了山峰的高度。
And, if those peaks grow tall enough, they can become so heavy that their weight overpowers the tectonic forces pushing them upward, and uplift stops.
如果这些山峰长得足够高，它们会变得非常重，以至于它们的重量超过了推动它们向上的构造力，这时隆起就会停止。
As the pieces of crust keep pushing together, the pressure leads to shortening and thickening under lower peaks instead,
随着地壳碎片不断挤压在一起，压力会导致较低峰缩短和增厚，
causing the slopes on either side of the central peaks to rise.
导致中心山峰两侧的斜坡上升。
So when the mountains can't grow upward anymore, they expand outward into plateaus.
因此，当山脉不再向上生长时，它们就会向外扩展形成高原。
This has been observed in mountains all over the world, from the Rockies to the Andes to the Himalayas.
从落基山脉到安第斯山脉再到喜马拉雅山，世界各地的山脉都观察到了这种现象。
And though we don't have an exact number for max height, we can assume Everest is pretty close to it,
虽然我们没有关于最高高度的准确数字，但我们可以假设珠峰非常接近这个值，
since it and other mountains in its range started growing outwards instead of up.
因为它和它范围内的其他山脉开始向外生长，而不是向上。
But the mountain might be a bit shorter now than it used to be, and that's because there's another possible limiter on mountain size: ice.
但是这座山可能比以前矮了一点，这是因为还有其他可能的因素限制了山脉的规模：冰。
The idea is that once a peak reaches high enough into the atmosphere, glaciers begin to form which then slowly carve at the summit.
这种想法是：一旦山峰达到触及大气层的高度，冰川就开始形成，然后冰川慢慢侵蚀山峰。
You see, mountains around the world all seem to top out at about 1500 meters above the local snowline
世界各地的山脉似乎都在当地雪线以上约1500米的地方达到极限
—an altitude which varies depending on the climate of the region.
——这一高度取决于该地区的气候。
And this trend suggests that glacial erosion carves away mountains faster than they can grow their tallest peaks, a hypothesis known as the glacial buzzsaw.
这一趋势表明冰川侵蚀山脉的速度比它们长出最高峰的速度还快，这一假说被称为“冰川电锯”。
But there are some mountains that don't seem to suffer from the glacial buzzsaw: highly active volcanoes.
但还有一些山脉没有出现冰川电锯现象：高度活跃的火山。
It's not because their lava melts the ice or anything, but because they form somewhat differently from other mountains.
这并不是因为它们的熔岩融化了冰或其他东西，而是因为它们的形状与其他山脉有些不同。
Mauna Kea on the island of Hawaii measures more than 10,000 meters from its base at the seafloor to its peak,
夏威夷岛上的莫纳克亚山从海底基地到山顶的距离超过1万米，
making it technically taller than Everest, though the majority of it is underwater.
虽然山脉大部分都在水下，但严格来讲，它比珠穆朗玛峰还要高。
It's so big because it's a shield volcano that formed through successive eruptions depositing layer upon layer of lava.
它之所以这么大是因为它是一个盾状火山，是由连续的火山喷发，一层又一层的熔岩沉积而成。
Like other mountains, Mauna Kea causes the crust beneath it to sag downward—
和其他山脉一样，莫纳克亚山造成它下边的地壳向下凹陷—
it and its neighbor Mauna Loa depress the seafloor by as much as 6,000 meters!
它和旁边的莫纳罗亚火山则将海底压低了6千米！
But that weight doesn't keep it from growing since it's growth doesn't depend on tectonic uplift.
但这个重量并没有抑制它的生长，因为它的生长不依赖于构造隆起。
And it's thought that the speed of volcanic buildup can outpace glacial erosion.
人们认为火山形成的速度可以超过冰川侵蚀的速度。
In fact, Mauna Kea probably would be taller, except it lost its fuel source.
事实上，莫纳克亚山可能会更高，除非它失去了燃料来源。
The mountain formed because a mantle plume beneath the crust produced magma which powered the volcano—
山脉的形成是因为地壳下的地幔柱产生的岩浆为火山提供了动力—
But now, the plate has moved it away from this plume, slowing the pace of eruptions.
但现在，板块将它移离了地幔柱，减缓了喷发的速度。
There are bigger mountains in our solar system, though.
不过，我们的太阳系中还有更大的山脉。
On Mars, the crust doesn't move around like it does on Earth, and there's less gravity pulling things down—
在火星上的地壳运动和在地球上的不一样，并且将事物牵扯向下的重力少了—
which is how Olympus Mons is able to reach a staggering 25,000 meters above the surrounding plains!
也因此奥林匹斯山的海拔能够达到令人震惊的25000米！
Sadly, a mountain that large is probably not possible on Earth. Physics just aren't on our side.
可悲的是，这么大的山脉在地球上或许不可能存在。物理学不支持我们。
"How big can mountains get" is the kind of question that forces you to apply everything you learned in science, math, and engineering courses.
“山能有多大”这个问题会迫使你把你在科学、数学和工程课程中学到的所有知识都应用到这个问题上。
And if you like that kind of thing, you'll probably really enjoy a subscription to Brilliant.org.
如果你喜欢这样的问题，你或许会想要订阅Brilliant.org。
You see, Brilliant's Daily Challenges make you think about how the world works and apply your scientific reasoning skills.
Brilliant的每日挑战会让你思考，世界如何运转并运用你的科学推理技巧。
And there are new ones every day, so they're kind of a daily workout for your brain.
每天都有新挑战，你的大脑每天都能得到锻炼。
And if you're worried your brain is a bit out of shape for that kind of daily grind,
如果你担心你的大脑有点不适合这种每日挑战，
well, Brilliant has you covered there, too, with over 50 engaging, interactive courses on everything
Brilliant上还有各种迷人的交互式的课程
from algebra and puzzle-solving to quantum mechanics and differential equations.
主题涉及代数、解谜量子力学和微分方程。
If you're one of the first 200 SciShow viewers to sign up at Brilliant.org/SciShow, you'll get 20% off an annual Premium subscription.
前200名注册Brilliant.org/SciShow的《科学秀》观众将获得8折优惠。
And you'll be supporting SciShow, too, so thanks!
这样是在支持《科学秀》，所以感谢大家！
