The entire universe may be rotating—just like its individual components, from massive galaxies to solar systems and planets—a possibility that could help explain the long-standing “Hubble tension” that has puzzled scientists for years. None of the currently accepted models of the universe account for any overall spin. Instead, they describe it as expanding uniformly in all directions. However, these models run into trouble with the so-called Hubble tension, a discrepancy where different methods of measuring the universe’s expansion yield conflicting results. “To paraphrase the Greek philosopher Heraclitus of Ephesus, who famously said ‘Panta Rhei’—everything moves—we thought that perhaps Panta Kykloutai—everything...