Astronomers who examined the sound waves from the Big Bang say that the Earth — and the entire Milky Way galaxy we call home — could be trapped in a huge void billions of light years across.
Their study, which was just presented at the Royal Astronomical Society's National Astronomy Meeting in the UK, could solve one of cosmology's greatest mysteries: the Hubble tension, or why the older universe appears to be expanding more slowly than younger regions. (Whether it could also explain why our world is a humongous mess remains unclear.)
"The Hubble tension is largely a local phenomenon, with little evidence that the expansion rate disagrees with expectations in the standard cosmology further back in time," Indranil Banik, a cosmologist from the University of Portsmouth who led the research, said in a statement about the work. "So a local solution like a local void is a promising way to go about solving the problem."
Our universe is expanding at an accelerated rate, but precisely what rate is a matter of intense debate. When astronomers analyze the cosmic microwave background, the light leftover from the Big Bang and the oldest light in the universe, the rate is slower compared to that derived from observations in the nearby universe of Type Ia supernovas and luminous, pulsing stars known as Cepheids.
The discrepancy has become undeniable, and its implications are so profound that it's been dubbed a "crisis in cosmology." Is our understanding of the universe wrong? Is there some new physics we are yet unaware of?