# Large Hadron Collider **Domain:** Particle Physics / Scientific Instrumentation **Doc Type:** Research Infrastructure Node **Maturity:** Operational **Primary Source:** [[articles/The Art is Long|The Art is Long: Vespucci of Immortality]] **Related:** [[wiki/CERN|CERN]], [[wiki/Observer Stack|Observer Stack]], [[wiki/hls4ml|hls4ml]], [[wiki/Recoverability|Recoverability]] --- ## Definition The **Large Hadron Collider (LHC)** is CERN's high-energy particle collider and a distributed instrumentation, trigger, storage, and analysis system. ## Observer-Stack Context Collision detectors produce signals at a rate far beyond permanent retention capacity. Hardware and software triggers therefore select a small fraction of events under strict latency constraints before the rest are irreversibly lost. The LHC makes the observer stack visible as a physical necessity: selection determines what can enter the scientific record.