Flux

Flux refers to the flow or transfer of a physical quantity—such as energy, particles, or fluid—through a specific area over a certain period of time. Think of it as the rate at which something passes through a surface; for example, the amount of sunlight reaching a surface per second, or water flowing through a pipe's cross-section. In science and engineering, understanding flux helps us quantify these flows, analyze processes, and design systems effectively. It’s a fundamental concept used across fields like physics, meteorology, and electrical engineering to describe how quantities move within a system.