So, in order to have fast transmission you do that by transmitting electrical signals; that happens pretty quickly.

所以 为了使信号迅速地传播,细胞使用电信号,它速度非常快

耶鲁公开课 - 生物医学工程探索课程节选

Let's talk about velocity just for completeness.

为了完整起见，我们接下来要讲速度。

麻省理工公开课 - 固态化学导论课程节选

And this is a very fast speed, of course, it's about 700 million miles per hour. So, one way to put that in perspective is to think about how long it takes for a light beam to get from earth to the moon. Does anyone have any guesses? Eight seconds, that sounds good.

当然这是一个非常快的速度，它大约是每小时7亿英里,为了更形象化，我们,看看光从地球到月球,需要多少时间，你们猜猜是多少？,8秒，猜的不错。

麻省理工公开课 - 化学原理课程节选