They did not yet understand that they were seeing the problem from the opposite direction.

VOA: special.2009.04.21

This was a problem but the direction is constantly changing.

在这个问题中,但是方向是在不断变化的

耶鲁公开课 - 基础物理课程节选

This was a problem but the direction is constantly changing.

在这个问题中,但是方向是在不断变化的

耶鲁公开课 - 基础物理课程节选