Fluorine is an extremely reactive chemical element with atomic number 9. At standard conditions, pure fluorine is a toxic pale yellow diatomic gas. Fluorite, the element's primary mineral source, was first described in 1529, and fluorine was proposed as an element in 1810. As the lightest halogen and most electronegative reactive element, it is difficult to separate from its compounds, and several early experimenters died or were injured in the attempt. French chemist Henri Moissan finally succeeded in 1886 using low-temperature electrolysis, a process still used today. Global fluorochemical sales amount to more than US$15 billion a year, including in toothpaste and water fluoridation, refrigerants, Teflon for electrical insulation and cookware, pharmaceuticals, aluminium refining and steelmaking. Fluorocarbon gases are generally greenhouse gases. Fluorine has no known metabolic role in mammals, but a few plants and sea sponges synthesize poisonous fluorocarbons to deter predators. (Full article...)

Māori warrior on the New Zealand shilling

• ... that the Māori warrior on the New Zealand shilling (pictured) was actually depicted wearing a dance uniform?
• ... that with Gogoliad, Dmitri Shostakovich ended his film career with Grigori Kozintsev, the same director with whom he started?
• ... that during the Mongol campaigns in Siberia, the Mongols defeated rival tribes at the Battle of Irtysh River?
• ... that in 2014, BBC Three cancelled a debate on being gay and Muslim featuring Asifa Lahore, a Muslim drag queen, citing security concerns at the mosque where it was filmed?
• ... that "Thy Strong Word" replaced an anti–Mexican–American War hymn in the Episcopal Church?
• ... that despite Daniel Lopatin's electronic album Chuck Person's Eccojams Vol. 1 having a limited 2010 release on cassette tapes, it became a foundational album for the vaporwave genre?
• ... that Shanthi Kalathil believes Radio Free Asia "filled a critical role in combating Chinese disinformation"?
• ... that a pornographic screenplay about Jesus led to papal and royal condemnations, a firebombing, the writer's ban from the UK, and thousands of letters per week demanding the ban of a non-existent gay Jesus film?

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