"Frederic Schuller's lecture notes on General Relativity," she said. "He derives the Einstein field equations from the Hilbert action on page 142."
After the defense, she walked back to her apartment. The red-rubber-banded stack of Schuller’s notes still sat on her desk, now dog-eared and coffee-stained. She opened the PDF again, not to study, but to read the acknowledgments at the end—a section she had always skipped. frederic schuller lecture notes pdf
She looked out her window at the rain streaking down the glass. The droplets followed geodesics, she realized. Not because a force pushed them, but because the geometry of the air-spacetime system demanded it. The Earth’s mass curved the manifold, and the raindrops were simply following the straightest possible paths—the geodesics—in that curved geometry. She opened the PDF again, not to study,