Ever thought about how weather is predicted so well or how we can gain knowledge of a galaxy's life cycle without observing it for billions of years? In earlier times scientists had only two choices: derive some theory or make some experiments. Today's grand challenges to research, like climate prediction, semiconductor technology, biotechnology, or materials sciences, need virtual experiments performed on a computer. Working in this thriving field, i.e. scientific computing, means dealing with both mathematical and informatical fundamentals and getting familiar with the background of the field of application. In this video scientists from mathematics, computer science, physics, mechanical and electrical engineering, and medicine join their efforts for better mathematical models, faster numerical algorithms, enhanced numerical software for supercomputers, and up-to-date experimental validation techniques. This film will allow an insight into the wonderful world of numerical simulation.