Leisure does not simply mean rest or inactivity but leisure is necessary for education or what he sometimes calls by the term philosophy.

安逸不单意指休憩或静止不动,安逸是教育的必备条件,或是套用,他有时会使用的词汇－哲学。

耶鲁公开课 - 政治哲学导论课程节选

It's very clear you don't need a force if something is doing nothing, just sitting there.

显而易见,如果物体没有运动,只是静止状态,那是不需要力的

耶鲁公开课 - 基础物理课程节选

Because we find in that plane, when objects are left at what you think is at rest with no external agency acting on them, they all slide backwards towards the rear end of the plane.

因为我们发现,在飞机上,当物体掉在地上,你认为它不受外力作用,应该保持静止时,它却朝着飞机的尾部滚去

耶鲁公开课 - 基础物理课程节选

The Law of Inertia says that, "If a body has no forces acting on it, then it will remain at rest if it was at rest to begin with, or if it had a velocity to begin with, it will maintain that velocity."

惯性定律就是,"如果一个物体不受外力作用,那么静止的物体依然保持静止,如果物体有个初速度,那么就保持此速度不变"

耶鲁公开课 - 基础物理课程节选