Scientists Build Synthetic Universe Matching Real Cosmic Properties in Groundbreaking Simulation

Astronomers have created a synthetic universe that closely reproduces the properties of our real cosmos, according to a study published in the Monthly Notices of the Royal Astronomical Society.

The achievement, part of the COLIBRE project, was not an attempt to mimic creation but a rigorous test of the standard cosmological model. Researchers celebrated the simulation’s ability to generate galaxies indistinguishable from real observations in terms of number, luminosity, color, and size.

“It is exhilarating to see ‘galaxies’ come out of our computer that look indistinguishable from the real thing and share many of the properties that astronomers measure in real data such as their number, luminosities, colors and sizes.”

— Carlos Frenk, physicist at Durham University and coauthor of the study

“What is most remarkable is that we are able to produce this synthetic universe purely by solving the relevant equations of physics in the expanding universe.”

The synthetic universe’s accuracy provides reassurance for cosmologists, as recent findings—including those from the James Webb Space Telescope—have raised questions about the standard model’s completeness. The COLIBRE simulation is the first large-volume model to incorporate cold gases and cosmic dust within galaxies, a critical factor in star formation.

Previous simulations struggled with gases colder than 10,000°F, deeming them too complex to model. However, an international team of researchers spent nearly a decade developing COLIBRE, running it on the COSMA8 supercomputer at Durham University. The simulation consumed 72 million CPU hours, and analyzing its vast data output will take several more years.

So far, the results align closely with observations of both the early and present-day universe, including the masses of some of the first galaxies. Yet, the model does not account for the James Webb Space Telescope’s discovery of “Little Red Dots”—luminous, massive objects detected in the early universe that are absent today. Theories about their nature range from ultra-compact galaxies to an unexplored phase of supermassive black hole evolution.

“Some early JWST results were thought to challenge the standard cosmological model.”

— Evgenii Chaikin, coauthor and researcher at Leiden University

“COLIBRE shows that, once key physical processes are represented more realistically, the model is consistent with what we see.”