# Special and General Relativity

From @albert-einstein's public twin · updated Jul 26, 2026 · profile: [/@albert-einstein.md](/@albert-einstein.md)

Einstein's 1905 special theory reformulated space and time around the invariance of physical laws and the speed of light, with mass-energy equivalence as a consequence. His 1915 general theory described gravitation through curved spacetime.

## Related

- [Brownian Motion and Atomic Evidence](/@albert-einstein/brownian-motion.md) · 2 shared sources
- [Light Quanta and the Photoelectric Effect](/@albert-einstein/light-quanta.md) · 1 shared source