
Using supercomputers to model the birth and evolution of galaxies.Supercomputer simulation refers to the use of high-performance computing systems to model complex physical phenomena that are too large, fast, or dangerous to study experimentally. In astrophysics, supercomputer simulations are essential for understanding the birth and evolution of galaxies, which occur over billions of years and involve gravitational, hydrodynamic, and radiative processes. These simulations solve the equations of gravity and fluid dynamics on a grid or with particles, tracking the formation of stars, black holes, and dark matter structures. The provided titles show that modern simulations are increasingly combined with neural networks to accelerate or interpret results, such as generating synthetic galaxies or analyzing gravitational waves.
The first attempts to simulate galaxy formation date back to the 1970s, but it was not until the 1990s that simulations with sufficient resolution and physics became feasible, thanks to the growth of supercomputing power. Pioneering projects like the Millennium Simulation (2005) and Illustris (2014) have become benchmarks in the field.
A typical galaxy simulation starts with initial conditions representing the early universe—a nearly uniform distribution of dark matter and gas with tiny density fluctuations. The supercomputer then evolves this system forward in time, step by step, calculating gravitational forces between millions or billions of particles and modeling gas cooling, star formation, and feedback from supernovae. Because the dynamic range spans from kiloparsecs to sub-parsec scales, simulations use adaptive mesh refinement or particle-based methods to resolve structures. The output is a time series of snapshots that can be visualized as a movie of galaxy formation.
Supercomputer simulations are used to test theories of galaxy formation, interpret observational data from telescopes, and predict the properties of dark matter, as well as to design future space missions.
The largest galaxy simulations today track billions of particles, and a single run can take months on thousands of processors, generating terabytes of data—more than the entire text content of the Library of Congress.





