Our Universe Is Rotating, Simulation Shows, and That Explains a Lot

Galileo Galilei’s legendary phrase “And yet it moves!”, allegedly said after his trial by the Inquisition for refuting the geocentric model of the solar system, may soon be applicable to the entire Universe. Signs of its rotation have already been detected by scientists, and the new work is the first step toward modeling this phenomenon.

A long-exposure image of Earth’s sky. Image credit: KPNO/NOIRLab

Previously, there have been published works that make one think about the possible rotation of our entire universe. In particular, in February 2025, based on the results of observations by the James Webb Observatory, a study was conducted that showed a sharp imbalance in the directions of rotation of galaxies in the early Universe. In the case of a non-rotating Universe, purely statistically, the directions of rotation of galaxies should be distributed approximately equally. In practice, it turned out that about 75% of galaxies rotate in one direction, and about 25% in the other. The Milky Way, by the way, is included in those same 25% of “incorrectly” rotating galaxies.

The predominance of one direction of rotation of galaxies may indicate that matter in space was already rotating before the formation of stars and galaxies – and at the maximum possible speed, which also set the momentum of rotation of more complex matter that appeared in the Universe. But even in the 13.8 billion years of its existence, the Universe has not managed to make even one complete rotation. This may take trillions of years.

Strictly speaking, in the new work, the scientists did not try to create the most complete model of the rotating Universe. This task will be solved in the next stages of research. So far, they have only demonstrated the influence of the Universe’s rotation on the Hubble constant – a value characterizing the speed of its expansion, which remains one of the main mysteries of modern cosmology. More precisely, with the help of the hypothesis of a rotating Universe, the scientists tried to explain the so-called “Hubble tension” – the discrepancy between the speed of the Universe’s expansion in the early era and in the modern era.

The curve shows the change in the Hubble constant for a rotating universe. Image credit: MNRAS 2025

The simulation has coped brilliantly with the task. If the Universe really does rotate, this could explain why its expansion rate in the first millions of years was slightly lower than what is observed today. Moreover, the model of a rotating Universe remains consistent with other cosmological models of its development. The researchers promise to create a more accurate model in order to further search for confirmation of the hypothesis of rotation in the entire array of astronomical observations.