Because it's so dense, there's not much room for light waves to travel, which means down here, it's pitch black.

因为压力是如此密集，所以没有多的空间让光传播，这意味着这里会漆黑一片。

Branches from this episode are how do sound waves travel?

本集的分支问题是声波如何传播？

And how fast do these waves travel?

这些波的传播速度有多快？

First, note the direction that the wave is traveling, in the x-direction.

注意向量在 -x 中的行进方向。

Today, you learned about traveling waves, and how their frequency, wavelength, and speed are all connected.

今天，您了解了行波，以及它们的频率、波长和速度如何相互关联。

And as we've talked about, sound waves are nothing but traveling pressure waves through the air.

正如我们所讨论的，声波只不过是通过空气传播的压力波。

And researchers found that P waves travel through both liquids and solids, while S waves travel only through solid matter.

同时研究人员发现P波能穿行液体和固体两种，而s波只能穿行固体物质。

But you might say that it does have special powers, because it’ll demonstrate for us the physics of traveling waves.

但你可能会说它确实有特殊的能力，因为它会为我们展示行波的物理特性。

But you might say that it does have special powers, because it'll demonstrate for us the physics of traveling waves.

但你可以说它具有非凡的力量， 因为它将向我们解释行波的物理学。

You might remember when we talked about traveling waves that a wave's speed is equal to its frequency times its wavelength.

你可能还记得当我们谈到行波时，波的速度等于它的频率乘以波长。

According to NASA, the misconception originated that no sound is in space because most of space is a vacuum where sound waves cannot travel.

据美国宇航局称，这种误解源于太空中没有声音，因为大部分太空都是真空，声波无法传播。

This early form of SONAR was a huge success, in large part because sound waves travel even faster through mediums with more tightly packed molecules, like water.

这种早期形式的 SONAR 取得了巨大的成功，这在很大程度上是因为声波在具有更紧密分子的介质（如水）中传播得更快。