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Mathematics

What Is Curvature and How Do We Measure It?

Quick fact

On a perfectly straight line, the curvature is zero. On a circle, the curvature is the same at every point and equals 1 divided by the circle’s radius.

Why this is interesting

You’ve likely heard that space itself bends around massive objects, but what does it actually mean for something to be curved? And how can we measure that bend with numbers?