2025 - Short Course on Computer Simulation in Today's World

Since the very beginning, in the late 1940s, computers have been used not only for data storage, organization and analysis, but also for simulation and forecasts. For example, the idea of using computer models for weather forecasting was initiated at the US Weather Bureau headquarters in January 1946, and the first operational computer-generated forecasts were issued in May 1955. Since then, the science of computer simulation has expanded exponentially. Today, all fields of science and engineering are investigated via computer simulation, especially those fields (e.g., astronomy and climate) where actual physical experiments in laboratory conditions are impossible (or too expensive).
Once a physical system is correctly simulated by a computer program, the same program can be used to evaluate "what if" scenarios, thus providing useful information to decision makers. For example, the same model that correctly simulated the sinking of Venice due to historical underground water extraction, can be used to simulate a possible reversal phenomenon with future injection of water underground. Computer models can also be used in forecasting mode to predict short-term or long-term events. For example, a global atmospheric circulation model can simulate the trajectory and impact of an accidental radioactive release on a scale of hours/days. And an econometric model can simulate the evolution of selected parameters (e.g., inflation, GNP) over a scale of months/years. Monte Carlo methods can be added to simulation models to include variations and uncertainties, thus obtaining a spectrum of likely results, instead of a unique solution.
Recently, computer simulation has expanded to cover every aspect of our lives. Traffic models provide drivers in real time with best alternative routes. Large entities (e.g., hospitals, amusement parks) rely on computer models to operate, purchase and storage products, and optimize operations. Often, even a minor change suggested by a computer program can provide improved efficiency and million dollars savings. These developments have created the need for specialized experts to develop models and algorithms, run the computer codes, and interpret the results. These fields are a major job opportunity for a new generation of scientists.