First of all, negative time should not bother anybody; t=0 is when I set the clock, I measured time forward, but yesterday would be t = -1 day, right?

首先,负的时间对我们不存在任何干扰,t=0使我们设定的初始时间,我是用顺序计时,所以昨天就可以记为-1天,对吗

耶鲁公开课 - 基础物理课程节选

suppose I asked you to time a 100 meter spring in the Olympics, but I give you a stopwatch that is measured in units of 15 seconds?

如果我要求你,在奥林匹克数给100米短跑计时，但我会给你一个秒表,它可以测出15秒的大小？

麻省理工公开课 - 固态化学导论课程节选

The unit for time will be a second, and time will be measured in seconds.

时间的单位是"秒",时间都是按秒来计的

耶鲁公开课 - 基础物理课程节选

You could take weights on people measured over a period of many years and look at the variability over time in weight and then link it to things like heart disease and cancer, and I'll come back later and talk about the results of that particular study.

我们还可以得到人们很长一段时间里,每年的体重数据,观察体重随着时间变化的变动,并将观察结果与心脏疾病和癌症联系起来,我等一下会告诉大家这项研究的结果

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

So, time is measured as a parameter along the motion of the particle.

这样,时间就被记为质点运动的一个参数

耶鲁公开课 - 基础物理课程节选