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Astronomy

The Shape of the Universe: Topological and Geometric Constraints

Quick fact

Observations of the cosmic microwave background have shown that the universe is geometrically flat to within 0.4%, meaning the geometry of space follows Euclidean rules—where parallel lines never meet, and the angles of a triangle sum to 180 degrees—on a cosmic scale.

Why this is interesting

Have you ever wondered if the universe has an edge, or if it wraps around like a video game screen? Its shape isn't just a philosophical puzzle—it's actually dictated by the laws of physics and measurable by telescopes.