Manatees fart to maintain the right buoyancy in water.

海放屁是为了在水中保持适当力。

Their size gives them increased buoyancy and musculature to be great swimmers.

它们体型增了它们力和肌肉组织，使得它们成为了优秀游泳运动员。

Their natural buoyancy comes from their body structure.

它们自然力来自于它们身体结构。

Any such churning is overwhelmed by the extra buoyancy of the warmer surface layers.

海洋任何搅动都被表层海水所增力给掩盖了。

It's buoyant, it weighs less than the milk it displaces.

它是有力，它重量比它排开轻。

So as you travel deeper, the buoyancy force from the metallic hydrogen counteracts gravity's downward pull.

所以当你下降得更深，来自金属氢力，抵消掉向下重力。

But buoyant objects don't rely on surface tension, so they continue surfing the meniscus.

但是有力物体不依赖于表面张力，所以它们会继续在弯月面动。

Floating in space is similar to floating in water, so astronauts practise their spacewalk in swimming pools.

在太空中受到力和在水中受到力相同，所以宇航员在泳池中练习太空行走。

The way we practise spacewalk is in water. Water gives us the neutral buoyancy that we need.

我们训练太空行走是在水中进行。水能给我们提供我们需要中性力。

A buoyant object will always be pushed up the liquid to the highest point on a meniscus.

有力物体总是会被向上推到弯月面最高点。

And I argued if one balloon provides some unit of lift, why wouldn't we be able to scale that?

我想说，如果每个气球都能提供一定力，那我们多用些气球不就行了吗？

A buoyant object will always repel something held up by surface tension's stretchy membrane.

一个有力物体总是会排斥由表面张力弹性膜支撑东西。

And that buoyant object did the opposite, it floated to the middle.

而那个有力物体则相反，它漂到l了中间。

If the length or diameter of the bamboo is not long enough, it will not be buoyant enough to float.

如果竹子长度或者直径不够，便不会产生足够力。

Tiny hairs on their legs trap air bubbles and increase their buoyancy.

它们腿上细毛捕获气泡并增它们力。

In turn, a buoyant force equal to the weight of the displaced water pushes up, counteracting you and your board's weight.

这会产生一股向上推力，其力量大小等同于被排开水重量，可以抵消你和冲浪板重量。

Our buoyancy, our swimming, our search for food, and, finally, his successful capture of a fish, all had to evolve together.

保持相同力、泳姿、找寻猎物，最后他成功捕获到一条鱼，这些全部都要配合得天衣无缝。

That's because the upward buoyant force is always stronger than the downward force of gravity.

这是因为向上力总是大于向下重力。

So when you're in salty water, you're gonna have a lot more buoyancy.

所以当你在咸水中时，你会有更大力。

So, being underwater already starts to destabilize  them, because it adds an uplift force.

所以，处于水下已经开始使它们变得不稳定，因为这会增一个向上力。