General Relativity's deep move: gravity isn't a force in space — it's the curvature of the stage itself, and things move by following the shape. Silicon has a real analog: the crystal lattice is the stage, its band structure is the curvature, doping warps the local geometry, and that geometry rewrites a carrier's effective mass — no force applied, just shape. Place a mass on the grid below and watch a carrier follow the curve.
| General Relativity | Silicon | |
|---|---|---|
| spacetime (the stage) | the crystal lattice | solid |
| curvature of spacetime | band structure (allowed energy bands) | solid |
| mass curves spacetime | doping/defects warp the local bands | solid |
| geodesic (free-fall path) | carrier drift along the band | solid |
| curvature strength | effective mass m* — carriers act lighter/heavier/negative | solid |
| event horizon / trapped zone | band gap / depletion region (forbidden) | solid |
| gravitational well | potential well / quantum dot | solid |
| test particles (matter) | electrons & holes (carriers) | solid |
| the cosmos (system stage) | the motherboard | stretch |
The realest part, and it's genuine condensed-matter physics: in a crystal, an electron behaves as if it has an effective mass different from its true mass — lighter, heavier, even negative — because the lattice geometry bends its motion. That is exactly GR's move: the shape of the stage rewrites the dynamics, no force required. A carrier in a curved band is like a mass in curved spacetime — both just follow the geometry, and the geometry decides how heavy they act.
Stretching to the board scale — labeled honestly as illustrative, not literal: