>[!warning] >This content has not been peer reviewed. # Matter has a maximum computation rate ## What it is (established result) Physical limits from quantum mechanics and relativity imply bounds on how fast information processing can occur in a finite physical system. A well-known estimate is **Bremermann’s limit**, giving a maximum rate of computation proportional to mass: \[ \text{ops/s} \;\lesssim\; \frac{M c^2}{h}, \] which is often quoted as a “computational capacity” per unit mass on the order of \(c^2/h\) \([1]\). More careful treatments add further constraints from finite signal speed and gravitational collapse, and relate these limits to quantum speed limits and black-hole bounds \([2,3]\). --- ## How RRT / RST uses it RST uses these limits as a **hardware governor** (A1/A4-style constraint) in a simulator: - Each tick has a maximum number of admissible “micro-evaluations” (candidate updates / checks). - If demanded compute exceeds the bound, the engine must **throttle time** (increase effective \(\Delta t\)) to remain within physical processing capacity — an explicit analog of time dilation as performance management. The `Reality Engine` demo implements this as a `BremermannGovernor` that computes a per-tick budget \(\propto M c^2/h\) and increases `dt` if the tick is oversubscribed. --- ## Links | Role | Link | |:---|:---| | Simulator application | [[further applications/Reality Engine/Reality Engine (RST)]] | | Simulator code | [[further applications/Reality Engine/Reality Engine - Code]] | --- ## References [1] H.-J. Bremermann, "Quantum Noise and Information," in *Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability*, Vol. 4, University of California Press, 1967. [2] N. Margolus and L. B. Levitin, "The maximum speed of dynamical evolution," *Physica D* **120**, 188–195 (1998), `https://doi.org/10.1016/S0167-2789(98)00054-2`. [3] S. Lloyd, "Ultimate physical limits to computation," *Nature* **406**, 1047–1054 (2000), `https://doi.org/10.1038/35023282`.