# Landauer Limit **Domain:** Physics / Computation / Continuity **Doc Type:** Formal Constraint Node **Maturity:** Developed **Related:** [[wiki/Energy Budget of Persistent Persons|Energy Budget of Persistent Persons]], [[wiki/Thermodynamic Constraints|Thermodynamic Constraints]], [[wiki/Computational Process|Computational Process]] --- ## Definition The **Landauer limit** is the thermodynamic lower bound associated with erasing one bit of information in a logically irreversible operation. At temperature \(T\), the minimum heat dissipated is: \[ E_{min} = k_B T \ln 2 \] where \(k_B\) is Boltzmann's constant. At room temperature this is on the order of \(10^{-21}\) joules per erased bit. ## What It Establishes Rolf Landauer's result connects information processing to physical entropy. Computation is not outside physics, and indefinite computational continuity cannot be literally resource-free. ## What It Does Not Establish The bound is not an estimate of the energy required to run a mind, preserve a person or operate a data center. Real systems dissipate far more energy through switching, memory movement, cooling, networking, redundancy and error correction. The number of irreversible operations required by a conscious process is also unknown. Multiplying a guessed mental bit rate by \(k_B T\ln 2\) therefore produces a theoretical floor, not an operating budget. Reversible computation may reduce the erasure component, but it does not remove the material costs of control, fault tolerance, input-output, storage maintenance or physical implementation. ## Continuity Relevance The Landauer limit disciplines two opposite errors: treating digital existence as immaterial, and treating a physics lower bound as a forecast of attainable service cost. Continuity planning belongs between those extremes, using measured system loads while preserving the lower bound as a statement of principle. ## Source - [IBM — Rolf Landauer and the physical nature of information](https://www.ibm.com/history/rolf-landauer) ## See Also [[wiki/Cost of a Continuant|Cost of a Continuant]] · [[wiki/Carbon Accounting for Continuity Infrastructure|Carbon Accounting for Continuity Infrastructure]] · [[wiki/Minimum Viable Continuity|Minimum Viable Continuity]]