Earth isn’t flat, but what about the universe? A bold new theory emerges

Produced by: Mohsin Shaikh

Cosmic puzzle

The universe may not be infinite or flat. Physicist Glenn Starkman and his team propose it could have a complex topology, possibly shaped like a 3-torus, resembling a hyperdimensional doughnut.

Microwave clues

The cosmic microwave background (CMB)—a faint remnant of the Big Bang—shows anomalies that hint the universe might curve back on itself, like Pac-Man’s screen.

Credit: ESO

Donut universe

Unlike simple shapes like spheres, a 3-torus topology loops in three dimensions. Traveling through one side could bring you back from the opposite side, like a cosmic corridor of mirrors.

Credit: ESO/J. Law

Repeating patterns

CMB analysis might reveal repeating patterns or cosmic “fingerprints” that suggest a curved universe, but the vastness of space makes such detection extremely challenging.

Copy worlds

If the universe loops, there could be duplicates of our world. However, the finite speed of light makes spotting these cosmic copies almost impossible with current tools.

Tech to rescue

ESA’s Euclid space telescope and machine learning tools are poised to map galaxy distributions and identify patterns that could validate the doughnut-shaped universe theory.

Risky pursuit

Theoretical physicist Yashar Akrami calls the idea “high risk, high reward,” while cosmologist Andrew Jaffe admits, “I’d be surprised if we find anything, but thrilled if we do.”

Credit: X

Einstein’s lens

Einstein’s theory of general relativity shows gravity can curve space, supporting the possibility of nontrivial topologies in the universe.

Endless exploration

Starkman’s team now considers 17 potential shapes, with each new discovery pushing the boundaries of understanding how space-time itself is structured.