" Lighter than air, " said Bernard, pointing upwards.

“比空气还轻。”伯纳说，指着天上。

How are they? - Lighter than air, but that's not the point.

好吃吗？ -好吃极了，但那不是重点。

Hydrogen gas is lighter than air, and people had used it for centuries to lift aircraft like hot air balloons.

氢气比空气轻，几个世纪以来，人们一直用它来抬升飞机，就像升起热气球一样。

He didn't tell Ron this, of course, but his heart felt lighter than air as he turned to leave the enclosure.

当然啦，他没有把这个想法告诉罗恩，但当他转身离开场地时，他觉得自己的心情比空气还要轻盈。

Instead, Zeppelin's Zeppelin had a framework inside and several cells of lighter than air gas keeping it airborne.

相反，齐柏林飞艇的内部有一个框架和几个比空气轻的气体单元，使其能够在空中飞行。

Things that are lighter than air are buoyant within it, while heavier objects require an upward force, called lift, to stay aloft.

比空气轻的物体在其中有浮力，而较重的物体需要向上的力（称为升力）才能保持在空中。

An " airship" is a type of flying vehicle that is lighter than air and that can move using its own power.

“飞艇”是一种飞行器，比空气轻，可以靠自己的动力移动。

Typically, airships are filled with a gas which is itself lighter than air and therefore allows the ship to float up into the air.

通常，飞艇充满了一种本身比空气轻的气体， 因此可以使飞艇漂浮在空中。

So maybe there are some solutions for our helium-related problems, but some applications are just going to require a noble gas that's lighter than air and there's only one of those.

因此，我们的氦相关元素的短缺问题可能有解了，但一些应用还需求比空气更轻的惰性气体，这样的惰性气体只有一种。

Helium is produced by the slow decay of radioactive materials in the Earth's crust and when it reaches the surface, because it's lighter than air, it just floats up right out of the atmosphere.

氦由地壳内部放射性物质慢速衰变产生，当氦抵达地表时，因为它比空气轻，所以就会上升，飞出大气层。