Edward Lorenz was an American mathematician and meteorologist, best known for his pioneering work in chaos theory. He discovered that small changes in initial conditions could lead to vastly different outcomes, a concept often illustrated by the "butterfly effect." This idea has significant implications in various fields, including weather forecasting and climate science. Lorenz's research in the 1960s laid the groundwork for modern chaos theory, which studies complex systems that are highly sensitive to initial conditions. His work has influenced not only meteorology but also areas such as economics, biology, and engineering, highlighting the interconnectedness of various scientific disciplines.