AI Insight
Current cosmological observations indicate that the universe appears geometrically flat on large scales, yet this measurement does not uniquely determine its global topology. Mathematicians and physicists have identified 18 possible three-dimensional shapes, known as Euclidean manifolds, that are consistent with a flat local geometry while differing in their overall structure. Among these possibilities is a toroidal shape, often compared to a donut, in which space wraps around on itself in one or more directions.
Why it matters
Understanding the true topology of the universe has fundamental implications for cosmology, including how we interpret the cosmic microwave background radiation and whether the universe is finite or infinite. Determining the actual shape could reshape foundational models in physics and our understanding of the origins and fate of the cosmos.
Our universe appears flat—but this observation still leaves plenty of options for its true shape. In fact, our cosmos could resemble a donut