Scientists Propose We Live in a Slowly Rotating Universe That Completes One Rotation Every 500 Billion Years

A team of scientists has proposed a revolutionary idea to explain one of the greatest contradictions in our understanding of the universe: the discrepancy in measuring its rate of expansion, known as the Hubble Tension. According to a study published in the journal Monthly Notices of the Royal Astronomical Society, the answer might lie in the fact that the universe rotates slowly, like a gigantic cosmic whirlpool.

For years, astronomers have measured the speed at which the universe is expanding, a value known as the Hubble constant (H₀). However, there’s a problem: measurements made in the nearby universe (using supernovae and stars called Cepheids) yield a higher value than those obtained from the radiation of the Big Bang (the oldest light in the cosmos, called the cosmic microwave background radiation).

This difference, which reaches a statistical significance of 5 sigma (which in science is considered very solid), has baffled experts and led to searches for explanations beyond the standard model of cosmology.

The Idea: A Rotating Universe

The study, led by Balázs Endre Szigeti and his colleagues, suggests that if the universe had a slow but constant rotation, this could explain the discrepancy. The idea is inspired by earlier work from mathematician Kurt Gödel, who imagined a rotating universe. Although Gödel’s original model had problems (such as the possibility of time travel), modern versions like the one proposed by the researchers avoid these complications.

According to the study, a rotation with an angular velocity today of approximately 0.002 turns per billion years (Gyr⁻¹) would be enough to reconcile the Hubble measurements. Interestingly, this value is close to the maximum allowed so that the rotational speed does not exceed the speed of light at the edges of the observable universe.

universe rotates slowly — Antennae Galaxies. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration / Wikimedia Commons

To understand it, imagine the universe as a dark fluid that rotates slowly. This rotation would act as an additional force affecting the expansion of the cosmos, similar to how centrifugal force pushes outward on a merry-go-round. The scientists used simplified fluid dynamics equations to model this effect and discovered that, with the right rotation, local Hubble predictions match observations.

What’s most striking is that this rotation, although minimal, would have a cumulative effect over billions of years. In the past, right after the Big Bang, the universe would have rotated much faster (about 3.5 million years per rotation), but over time, this motion would have slowed to its current value.

Is It Possible That the Universe Rotates?

The idea isn’t as far-fetched as it might seem. Everything in the universe rotates: planets, stars, galaxies, and even black holes. Moreover, there have been recent hints that the universe’s expansion might be slightly uneven in different directions, which would fit with a global spin. However, so far, no rotation has been detected in the cosmic microwave background radiation, which suggests that, if it exists, it would be extremely slow.

The authors acknowledge that their model is preliminary and needs to be tested against other cosmological observations. For instance, it would be necessary to see whether this rotation affects the formation of galaxies or the distribution of dark matter. Additionally, the study is based on Newtonian approximations, and a more precise description would require applying Einstein’s theory of general relativity.

Even so, the proposal is fascinating because it offers an elegant solution to the Hubble puzzle without introducing new particles or exotic energies, as other theories have done. If future research confirms this idea, it would change our view of the universe: not only is it expanding, but it is also rotating, like a cosmic ballet on an unimaginable scale.

SOURCES

Balázs Endre Szigeti, István Szapudi, Imre Ferenc Barna, Gergely Gábor Barnaföldi, Can rotation solve the Hubble Puzzle?, Monthly Notices of the Royal Astronomical Society, Volume 538, Issue 4, April 2025, Pages 3038–3041, doi.org/10.1093/mnras/staf446