Gravity is one force that acts on a body without the source of the force actually touching it.

引力是一种受力物体收到了力的作用,但却没有接触施力物体的力

耶鲁公开课 - 基础物理课程节选

Two pieces of memory actually touching each other or you touching memory that you don't actually own, in which case the computer doesn't really know what to do and just, bam.

两块内存相互覆盖,或者你覆盖了不存在的内存，那样的话计算机不知道,该怎么做，只有崩溃。

哈佛公开课 - 计算机科学课程节选

You've got a loop, you've got a condition and a boolean to check if he's touching the edge, and some statements to tell him to shout or to actually turn around.

我们有一个循环，通过一个条件和一个布尔值来判断,是否触到了边缘，还有一些语句,让它回头并咆哮。

哈佛公开课 - 计算机科学课程节选