Ad astra per intellectum.
Toward the stars by way of understanding.

Relativity and gravitation are gathered here as a study sequence rather than a finished treatise. The aim is to keep geometry, field equations, exact solutions, collapse, horizons, and cosmology within one continuous line of thought so that later frontier questions still remain anchored to the classical theory that makes them legible.

Chapter Atlas

Working Emphasis

• geometry first, then physical interpretation
• derivations kept close to the assumptions that justify them
• black-hole and horizon physics treated as the bridge from classical spacetime to quantum field theory on curved backgrounds
• source texts and lecture notes kept adjacent, so the archive remains readable rather than merely accumulative

Current Highlight

The newest demonstration note in this section is Hawking Radiation from Bogoliubov Transformations. It now sits as a subpage under Hawking Radiation, and gives a detailed lecture-note derivation of the Hawking spectrum from the mismatch between positive-frequency definitions at ${\mathcal{I}}^{-}$ and ${\mathcal{I}}^{+}$.