Fibonacci Day Nov. 23, 2025

Fibonacci Day

Look closely at this ammonite fossil. Its swirling shell, once home to a prehistoric sea creature, holds a mathematical secret—a spiral pattern. Each new chamber is proportionally larger than the previous one, maintaining a consistent growth ratio, often associated with the Fibonacci sequence.

© ThomasLENNE/Shutterstock

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Today in History

Nature, art, and...math?
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