According to the Priestly source, blood, the blood that courses through one's veins, represents the life force.

根据祭司资料，血,在人血管中流动，代表着生命的力量。

耶鲁公开课 - 旧约导论课程节选

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