(单词翻译:单击)
Hey there welcome to Life Noggin.
大家好！欢迎来到脑洞大开的生命奇想。
Why can't humans live underwater?
为什么人类不能在水下生活？
With everyone focusing on colonizing other worlds, maybe we can colonize other parts of the one we already have!
现在每个人都关注着移民到其他的世界，也许我们可以移民当前这个世界的其他地方！
Could we engineer ourselves to live in the ocean? Let's find out... and hopefully avoid anything hiding deep in the ocean.
我们能把自己改造一下以便生活在海洋里吗？一起来看一下，希望不会碰到隐藏在海洋深处的那些东西。
Because we already did a video on that. And it's scary. So why can't humans breathe underwater?
因为关于那个我们已经做过一期视频了。真可怕。那么为什么人类不能在水下呼吸呢？
Well, human respiratory systems were designed to get oxygen from air, which we need to live.
人类的呼吸系统原本要从空气中获取氧气，供我们生存。
Oxygen from the air you inhale makes its way through your body, eventually being absorbed by your blood.
你从空气中吸收氧气，氧气通过你的身体，最终被血液吸收。
Your heart then pumps all that blood throughout your body to provide that oxygen to the cells of your tissues and organs.
然后你的心脏将血液泵入全身，为组织和器官的细胞提供氧气。
Carbon dioxide is produced and absorbed into your blood as the cells use the oxygen.
细胞使用氧气，会产生二氧化碳，二氧化碳又被吸收到血液中。
This carbon dioxide is then eventually removed from the body as you exhale. But the air people breathe isn't just oxygen.
呼气的时候，这些二氧化碳最终会从身体中清除出去。但是人们呼吸的空气不仅仅是氧气。
In fact, the chemical makeup of the air you breathe is only about 21 percent oxygen.
事实上，你呼吸的空气中只有大约21%是氧气。
Since water is H20, a combination of hydrogen and oxygen, can't we get oxygen from water then too? Unfortunately, no.
既然水是H20，是氢和氧的结合，那么我们就不能从水中获得氧气吗？很不幸，不能。
To get oxygen underwater, we'd probably need to have gills like a fish.
为了在水下获得氧气，我们可能需要有像鱼一样的鳃。
However, even the primary source of oxygen that fish get is not from the oxygen in H2O, but from microscopic bubbles of dissolved oxygen in the water.
然而，鱼类的主要氧气来源也不是来自水中的氧气，而是水中的溶解氧微小气泡。
Many different gases can dissolve in liquids, which you can see when you open up your favorite can of carbonated beverage!
许多不同的气体可以溶解在液体中，打开你最喜欢的碳酸饮料，你就能看到了！
My favorite is Blocko Cola. It has zero calories because it's not real.
我最喜欢的是宝高可乐。它是零卡可乐，因为它不是真的。
Their gills are designed to utilize that dissolved oxygen in water, which is found in far lower concentrations than in air.
它们的鳃可以利用水中的溶解氧，而水中的溶解氧浓度远低于空气中的溶解氧浓度。
Also, if humans could be engineered to have gills, they might need to take in more oxygen with their gills than fish in order to survive for a long time.
而且，如果人类可以长出鳃，他们可能需要用鱼鳃吸入比鱼类更多的氧气，才能生存很长一段时间。
While there would probably be other things to take into account, like a change in diet and pressure differences, breathing underwater is one of the biggest obstacles we'd have to overcome to engineer ourselves to live underwater.
也许还有其他的事情需要考虑，比如饮食和压力的变化，但是在水下呼吸是我们要克服的最大的障碍之一。
We could maybe solve that problem if we could make humans with gills, or we could potentially live in the water if we could hold our breaths for significantly longer durations.
如果我们能让人类有鳃，或许我们可以解决这个问题，或者如果我们能屏住呼吸更长时间，我们可能就能生活在水里。
This is the case with animals like dolphins and whales, who still get their oxygen from air like people do. It would also be good if we could travel faster in the water as well.
海豚、鲸鱼等动物也是如此，它们仍然像人类一样从空气中获取氧气。如果我们也能在水里游得更快的话，那就更好了。
Researchers have found that the average sprinting speeds among swimmers is about 1.64 meters per second, or about 3.7 watery miles per hour.
研究人员发现，游泳者的平均冲刺速度约为每秒1.64米，约为每小时3.7英里。
However, even this speed is unlikely to be sustained over long distances.
然而，即使是这样的速度也不太可能维持很长的距离。
To put that in perspective, Tuna can swim as fast as 50 miles per hour for short bursts and typically move about 5-10 miles per hour for sustained periods of travel.
从这个角度来看，金枪鱼在短时间内速度可以到每小时50英里，在长途旅行中速度通常是每小时5-10英里。
While their fins sure do help them swim, fish often use their fins more for stabilization.
虽然鱼鳍确实能帮助它们游泳，但鱼通常更喜欢用鱼鳍来稳定自己的身体。
In many fishy cases, it's actually muscles on the sides of their body contracting that cause their tail to whip very rapidly from side to side, giving fish their speed.
许多鱼实际上是身体两侧的肌肉在收缩，使得它们的尾巴从一边迅速地甩到另一边，从而给自己加速。
There are some fishy super hero dude that would know a thing or two about that!
有个鱼类的超级英雄会知道这一点的！
So do you think people would ever be able to live underwater? Would you even wanna live underwater?
那么你认为人们能在水下生活吗？你想住在水下吗？
Let me know in the comments section below or tell me what should we talk about next!
请在下面的评论区告诉我，或者告诉我接下来我们该谈些什么！
Genetically modifying ourselves living underwater might seem awesome. But wanna know something more awesome?
从基因上改变自己以便生活在水下，这可能看起来很棒。但是想知道更棒的东西吗？
Genetically modifying mosquitoes to remove disease.
通过基因改造蚊子来消除疾病。
For more on that, I highly recommend you watch this video from our friends, Above the Noise, where they explore this very idea.
如果想了解更多，我强烈推荐你看看我们的朋友做的这期视频，《噪音之上》，在视频里他们会探索这个想法。
Make sure you go subscribe to them. They are one of my favorite channels.
你一定要订阅他们。它们是我最喜欢的频道之一。
My name is Blocko. This has been Life Noggin. Don't forget to keep on thinking!
我的名字叫宝高。这里是脑洞大开的生命奇想。思考不要停！
