What Is a Manifold? | Quanta Magazine

What Is a Manifold?

In the mid-19th century, Bernhard Riemann introduced a revolutionary way of understanding mathematical spaces, laying the groundwork for modern geometry and physics. Though we stand on a spherical Earth, it appears flat to us because of our limited perspective. Similarly, many shapes appear flat locally but have more complex global structures. Mathematicians call these shapes manifolds.

The Concept and Its Impact

Manifolds changed the way mathematicians view space: no longer just a backdrop for mathematical objects, space became an abstract entity worthy of study itself. This shift enabled rigorous analysis of higher-dimensional spaces and sparked the development of modern topology, the branch of mathematics focused on studying spaces like manifolds.

Applications and Importance

Manifolds now play a central role in various disciplines, including:

They provide mathematicians with a common language to solve diverse problems and are as fundamental to mathematics as the alphabet is to language.

“If I know Cyrillic, do I know Russian?” said Fabrizio Bianchi, a mathematician at the University of Pisa in Italy. “But try to learn Russian without learning Cyrillic.”

This analogy highlights that understanding manifolds requires grasping the underlying language of mathematics, not just isolated concepts.

Author’s Summary

Manifolds, introduced by Riemann, revolutionized the study of space, becoming essential tools across mathematics and science for understanding complex shapes and dimensions.

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Quanta Magazine Quanta Magazine — 2025-11-04