Einstein later recalled thinking. He came to realize that since all the laws of physics remain the same whether you're at rest or in steady motion, the speed of light has to be constant as well.
Einstein later recalled thinking. He came to realize that since all the laws of physics remain the same whether you’re at rest or in steady motion, the speed of light has to be constant as well.
An object in an inertial frame remains in motion or at rest until an external force acts upon it. The second postulate ...