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The math, myths, and magic of Friday the 13th
Uncover the surprising history, global twists, and hidden mathematics behind the world's most famous bad luck day.
4 chapters68 assets
by today · Nov 13, 2026
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Chapter 1
The roots of the rumor
1Loki crashes Valhalla's banquet
2The Last Supper's fateful table
3The dawn raid on the Knights Templar
4The Thirteen Club's defiant dinners
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Chapter 2
The math and calendar magic
1The 400-year calendar loop
2The most common day for the thirteenth
3The Sunday start rule
4The triplicate years
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Chapter 3
Global flavors of bad luck
1Tuesday's curse in Spanish-speaking cultures
2Italy's fear of the seventeenth
3The silent four in East Asia
4The lucky thirteen elsewhere
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Chapter 4
The science of superstition
1The mouthful that means fear
2The surprising safety of bad luck
3The phantom thirteenth floor
4The price tag of superstition
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