E. g. I The principle of relativity can be translated into simpler terms.

相对论的原理可以用较为简单的措词加以说明。

Newtonian gravity assumes action at a distance, in clear violation of the principle of relativity.

牛顿的重力理论假设了超距作用, 明显违反了相对论原理.

The well established principle of relativity, going all the way back to Galileo, stated that absolute motion could not be defined.

在两个基础的物理原理间，被广泛接受的相对性原理，在伽利略时期就已经被确立，它阐明绝对的运动是无法定义的。

Why does combining the principle of relativity with the invariance of the speed of light lead one to conclude that no medium is required for light to propagate?

为什么由相对论原理以及光速的不变性可以推导出光不需要介质即可传播?。