Exploring event distributions with a simple granular flow experiment

Abstract

Probability distributions describing random events are central to many areas of physics, from radioactive decay to photon detection. Yet laboratory demonstrations of counting statistics often rely on specialized, costly instrumentation that is unavailable in many educational settings. Moreover, traditional experiments typically present the underlying random processes as a ‘black box,’ limiting students’ ability to connect physical mechanisms with statistical models. This work introduces a simple, inexpensive, and visually transparent experiment in which granules are released from a funnel through manual mechanical shaking and collected on a digital precision balance. Rather than serving merely as a verification tool, the system naturally violates key prerequisites of the classical Poisson distribution due to funnel geometry and granular‑flow mechanics, thereby placing students at the center of active model evaluation. The proposed task offers an accessible introduction to counting statistics, stochastic processes, and data analysis for introductory physics courses.