After 50 years of silence, I think the time has come to take stock and say, maybe we should mobilize all of the sciences to look for anything fishy, anything weird,any anomaly, both in our own little corner of the universe here on Earth and in the solar system, and far out across the galaxy."

VOA: standard.2010.04.16

And this is literally a time of silence in a class.

也就是课堂上的安静时刻。

哈佛公开课 - 幸福课课程节选