Claims

Two years after Einstein's 1905 paper, mathematician Hermann Minkowski, who had been one of Einstein's professors, proposed that the correct interpretation of special relativity is to view space and time as a unified four-dimensional spacetime rather than separate entities, a mathematical reformulation Einstein initially dismissed as unnecessary but later recognized as useful for further development.

Einstein's solution to the Maxwell-Newton conflict was to reject the idea that electromagnetic waves travel through a medium and instead take literally Maxwell's equations that predict everyone measures the same speed of light, which required completely reconceptualizing space and time.

Einstein attempted to create a version of Newton's theory of gravity compatible with special relativity but found it impossible, which forced him to realize that gravity is not a force on top of spacetime but rather a feature of spacetime itself—specifically, spacetime geometry that is curved and dynamical, responding to the presence of mass and energy.

In classical mechanics under Newton's laws, space is absolute and agreed upon by everyone; this assumption held for hundreds of years before being challenged by Einstein's theories of relativity.

Einstein's equations of general relativity are so complex that Einstein initially believed no one might ever solve them, but Carl Schwarzschild, a German astronomer who attended Einstein's lectures in Berlin, taught himself general relativity, solved the equations for the gravitational field around the sun, and returned from World War I to present the solution to Einstein, who immediately recognized its brilliance.

The development of electromagnetism in the 1800s revealed a conflict between Maxwell's equations and Newton's mechanics: Maxwell's equations predicted a special velocity (the speed of light), while Newtonian mechanics allowed all velocities to be equivalent, leading physicists to struggle for decades with reconciling this inconsistency.