时差N小时 隧道里没信号怎么办?(下)

（单词翻译）

They generally go from eighty-eight to one-hundred-and-eight megahertz.

通常会从88到108兆赫。

That's over a hundred million cycles per second.

超过每秒一亿次。

Wow! That's pretty fast.

哇!那可是相当快。

As a result, a single radio wave from an FM station is only a few meters long, about the size of a car.

结果，FM电台单一的无线电波只有几米长,约相当于一辆车。

An AM station is putting out radio waves that are hundreds of times as long!

而AM电台伸展数百倍长的无线电波!

So the longer wavelengths¹ can't make it as easily into tunnels?

那长的电波不是更容易进入隧道吗?

Long wavelengths tend to be absorbed or blocked as they try to enter the smaller tunnel.

长电波在试图进入较小的隧道时往往被吸收或阻碍。

The higher-energy and shorter-wavelength waves from an FM station aren't absorbed or blocked as much.

而FM电台的高能量和短波长电波没有被吸收或阻碍。

Instead, they tend to bounce² around and get reflected off of surfaces.

相反,它们被从表面反弹和反射。

Like the inside of a tunnel.

像是隧道里。

Yep. Of course, they only bounce so far.

是的。当然,它们只是反弹到这段。

If the tunnel is long enough, even FM stations fade out until you come out the other end.

如果隧道足够长,甚至直到你从隧道另一端出来FM电台也会渐渐弱化。

Here we are!

我们现在就出来了!