1879-1955. German-born theoretical physicist.
Developed special and general relativity, redefining spacetime, gravity, and the relationship between mass and energy (E=mc²).
Explained the photoelectric effect, confirming the quantum nature of light and contributing to the birth of quantum mechanics.
Predicted gravitational waves, gravitational lensing, and the equivalence principle.
His field equations describe the geometry of spacetime as shaped by mass-energy, the foundation of modern cosmology.
Demonstrated that observation and measurement are frame-dependent, a principle echoed in decentralized consensus and cyber protocol design.