› added 3 months ago

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TIL about the discovery of IR and UV light: in 1800, William Herschel discovered that in prismed sunlight the invisible area just beyond red light heats up; In 1801, Johann Wilhelm Ritter searched for "cooling rays" on the other end of the spectrum but instead found it induces a chemical reaction

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MLN8 TIL in 1926 a Pasadena mailman planted some avocado seeds intending to graft with the desirable Fuerte variety. The graft repeatedly failed on one tree and he was going to cut it down, but was advised to “wait and see what happens”. It became the mother tree from which all Hass avocados originate.
kJOYm TIL when the number of kangaroos was getting close to 50 million in 2017, Australians were encouraged to eat more kangaroo meat, as a means of population control.
7kgZ TIL in Sweden it is legal to sell sex for money, but illegal to buy it.
x6Nj7 TIL that average human height went down from 5'10" (178 cm) for men and 5'6" (168 cm) for women to 5'5" (165 cm) and 5'1" (155 cm) 10,000 years ago and it took until the 20th century for average human height to match pre-Neolithic Revolution levels.
X9PD TIL the reason that so many working-class British men wore a flat cap is that a 16th-century Act of Parliament designed to stimulate wool consumption penalized non-nobles over the age of 6 if they weren’t wearing a woolen cap.