... contraction non Euclidean geometry Euclidean geometry first law of motion geodesic sphere geometry of gravitational waves acceleration general relativity gravity mass mass-energy equivalence observer relativity space-time special relativity Early in the twentieth century, a landmark case came...

... of relativity and of the constancy of the speed of light, followed by a discussion on the relativity of simultaneity, the mass–energy equivalence, and experimental tests of special relativity. It also examines the principle of equivalence, the concepts of spacetime curvature and general covariance, and Mach’s...