* Special Relativity: This theory, developed by Albert Einstein in 1905, is based on two postulates:
* The laws of physics are the same for all observers in uniform motion.
* The speed of light in a vacuum is the same for all inertial observers, regardless of the motion of the light source.
* General Relativity: This theory, also developed by Einstein in 1915, extends special relativity to include gravity. It describes gravity not as a force, but as a curvature of spacetime caused by the presence of mass and energy.
So, depending on which "law of relativity" you're referring to, the answer is either 1905 for Special Relativity or 1915 for General Relativity.
