We thought we knew the shape of the universe. We were wrong

For decades, scientists believed the universe was flat like an infinite plane based on cosmic microwave background data that showed no circular patterns indicating the cosmos loops back on itself. However, new research from the COMPACT collaboration reveals this conclusion was flawed—scientists expected these telltale loops would intersect our line of sight, but loops can orient in ways that completely miss observers even when detectable. This means many cosmic shapes previously ruled out are back in consideration, leaving the universe's true form unknown and opening up numerous topological possibilities.