History
The Eiffel Tower Grows in Summer
The iron of the Eiffel Tower expands in heat, making it up to 15 cm taller in summer. This thermal expansion is a well-known property of metals.
Science
Honey Never Spoils
Archaeologists found 3,000-year-old honey in Egyptian tombs that was still edible. Honey's low moisture and acidic pH make it inhospitable to bacteria.
Science
Octopuses Have Three Hearts
An octopus has three hearts: two pump blood to the gills, while the third pumps it to the body. When swimming, the body-heart stops — which is why octopuses prefer crawling.
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