At the time, people believed that light waves, just as sound waves, ocean waves or shock waves, had to travel through a medium.

当时，人们认为，光波就像声波、海浪波或冲击波一样，它们的运行必须穿过介质。

youdao

The researchers also charted sound waves passing through nine quiet regions of the sun, where no sunspots were developing, and found no significant anomalies in the waves' travel time.

在无黑子活动的九个太阳宁静区，研究人员发现声波的传播时间没有这么大的变化。

youdao

It takes time for both light and sound to travel.

光和声音的传播都需要时间。

youdao

The NOAA ship Okeanos Explorer mapped the locations between Nov. 2 and Nov. 20 using multibeam sonar, which produces detailed images of the seafloor by calculating the amount of time and distance it takes for sound waves to travel from the ship to the seafloor and back.

MSN: Expedition finds 40 unknown gas seeps off US East Coast