The Fermi Paradox: Are We Alone in the Universe? With all those planets out there, you would expect that we would find intelligent life somewhere.

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The Hidden Rules of the Puritan Fashion Police. Any time fashions changed, new laws were put in place to forbid them.

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Caterpillar Tracks. The story of how we got modern tanks, tractors, and heavy equipment.

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Pitch Perfect: A History of Vocal Groups. Yes, there are videos.

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The Strange, High-Pressure Work of Presidential Interpreters. They are expected to not only be highly skilled at languages, but also intuitive, trustworthy, dedicated, and knowledgeable in other areas.

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The Massive Volcano That Scientists Can't Find. There are conflicting clues, so no one knows for sure what happened in 1465.

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Food Courts Are Out; Food Halls Are In. Yes, they are different.

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11 Monuments to Cats. They all deserve to be remembered.