Close up, you see that it's a vibrating string.

靠近一点，你会看到它是一根振动的弦。

Physics is the harmonies, the harmonies of vibrating strings.

物理是和声振动弦的和声。

Now, how many ways can one string vibrate?

一根弦有多少种振动方式？

And then, the vibrating string makes the bottom of the other cup move.

然后，振动的绳子使另一个杯子的底部移动。

String instruments create sound when their strings vibrate in the air.

弦乐器发出声音时 琴弦在空中振动。

The musician plucks the strings with the fingertips of both hands, producing sound as the strings vibrate through the soundboard.

音乐家用双手的指尖拨动琴弦，随着琴弦在音板上的振动而发出声音。

Four things affect the frequency of a vibrating string