"Hubble tension": Rotating universe could solve the riddle of cosmology
People are still puzzling over why nearby objects and distant galaxies move away from us at different speeds. There may now be a simple explanation.
A long exposure of the starry sky above the European Southern Observatory.
(Image: Zdeněk Bardon (bardon.cz)/ESO)
If our universe revolves around itself – and even if only very slowly – this could explain the so-called Hubble tension and thus one of the greatest mysteries of cosmology. At least that is the opinion of a research team led by astronomer István Szapudi from the University of Hawaiʻi. They developed a mathematical model of the universe that followed the “standard rules”. When they added just a small rotation to this, it made a big difference. Without contradicting other astronomical measurements, this small change helped to resolve the great paradox surrounding the speed at which the cosmos expands. However, further research is still needed.
Simple explanation for persistent discrepancy?
In astronomy and cosmology, an ever-increasing discrepancy in the so-called Hubble constant (H0) is referred to as “Hubble tension”. The latter is a fundamental quantity in cosmology that indicates the speed at which an object at a distance of one megaparsec (3.26 million light years) is moving away from us due to the expansion of the universe alone. This refers to objects outside our galaxy; the Andromeda Galaxy, for example, is 0.89 megaparsecs away from us. Measurements in the comparatively nearby universe now give a significantly different value for the constant than high-precision measurements in the epoch directly after the Big Bang.
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Szapudis now explains that, according to previous interpretations, the universe expands equally in all directions and does not revolve around itself. This is consistent with most astronomical observations. To the great surprise of his team, however, it did not harm the coherence of their model when such a rotation was added. On the contrary, this resolved the Hubble tension without contradicting other fundamental measurements. A comparatively slow rotation, in which the universe requires around 500 billion years for a complete rotation, was sufficient.
A universe that revolves around itself would not contradict any laws of physics, the research team assures us. At the same time, it could explain the persistent discrepancy in the Hubble constant. However, the model would have to be further developed to verify this, and at the same time it would be necessary to find out whether there are signs of such rotation in the real universe. Just a month ago, another research team made a puzzling discovery in the early universe that could also be explained by a rotating universe. The work of Szapudi's team is now presented in the Monthly Notices of the Royal Astronomical Society.
(mho)
