Irish-led study questions the shape of our universe

22 Nov 2023

Image: © quickshooting/Stock.adobe.com

A paper co-authored by Dr Eoin Ó Colgáin of Atlantic Technological University argues that the universe is less symmetrical than we think.

An international study led by Irish scientist Dr Eoin Ó Colgáin has flung into question our understanding of one of the most fundamental aspects of the universe: its shape.

For more than a century, scientists have explained gravity across various scales – from our solar system to the vast expanse of the universe – using Einstein’s theory of general relativity. And an assumption that has been a fundamental aspect of this paradigm is that the universe is isotropic, which means that the underlying spacetime remains uniform in all directions while it expands.

The assumption of an isotropic universe is supported by both the European Space Agency and NASA and greatly simplifies mathematical modelling and astronomical observations.

“The isotropic universe assumption has noticeable benefits,” said Ó Colgáin, a physicist and data scientist based at Atlantic Technological University.

“On one hand, it makes gravity equations easier to solve. On the other hand, astronomers can point telescopes in a single direction on the sky and assume findings are representative.”

But according to a paper published in Classical and Quantum Gravity earlier this year, Ó Colgáin and his team suggest that the expansion of the universe is not, in fact, a perfect bubble-type shape but has a less uniform look that bulges in different locations.

While cosmic microwave background radiation – relic radiation from the Big Bang – has been confirmed as isotropic to good approximation, matter distribution across the universe, such as atoms and electrons, have been shown to display what’s known as anisotropic patterns.

This idea that the universe may not be isotropic has garnered significant attention internationally, with the Royal Society London hosting a debate on the topic next year.

“The philosopher of science Thomas Kuhn separates science into normal science, marked by incremental advancements within a paradigm, and breakthroughs or paradigm shifts,” Ó Colgáin went on. “Our emerging results raise the exciting prospect that a paradigm shift is on the horizon.”

10 things you need to know direct to your inbox every weekday. Sign up for the Daily Brief, Silicon Republic’s digest of essential sci-tech news.

Vish Gain is a journalist with Silicon Republic

editorial@siliconrepublic.com