The first principle of Einstein's Special Theory of Relativity is that the speed of light is always the same regardless of the motion of the observer or the light source.
The first principle of Einstein's Special Theory of Relativity is that the speed of light is always the same regardless of the motion of the observer or the light source.
爱因斯坦的狭义相对论中第一条定律就是光速是恒定的，完全不依赖于观测者及光源的速度。