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Start swiping — it's freeSchopenhauer imagined a group of porcupines on a cold night, driven together for warmth, only to prick each other with their quills and scatter — then drift back together as the cold returns. He used it as a parable for human relationships: we need closeness, but closeness has a cost, so we settle on a bearable middle distance.
Ancient geometers spent over two thousand years trying to construct, using only an unmarked straightedge and compass, a square with exactly the same area as a given circle. Countless attempts failed. Was it simply a matter of not being clever enough, or is the task fundamentally impossible?
It's impossible, and the proof took until 1882. Ferdinand von Lindemann showed that pi is a 'transcendental' number — not the solution to any polynomial equation with rational coefficients — and only non-transcendental (algebraic) lengths can ever be constructed with compass and straightedge. Since squaring the circle requires constructing a length involving the square root of pi, the ancient problem was mathematically doomed from the start.
— Ferdinand von Lindemann, Squaring the circle — Proof of pi's transcendence, 1882
On 19 September 1783 the Montgolfier brothers sent a sheep, a duck and a rooster aloft in a hot air balloon to see if animals could survive at altitude. Two months later, on 21 November, Pilâtre de Rozier and the Marquis d'Arlandes became the first humans to fly, drifting nearly six miles over Paris in 25 minutes with no steering and no parachute.
— Richard Holmes, Falling Upwards: How We Took to the Air — Chapter 1, 2013
In 1952, anesthesiologist Virginia Apgar introduced a simple score, checking a newborn's color, pulse, reflexes, muscle tone and breathing one and five minutes after birth. It gave hospitals a fast, standardized way to spot babies in danger, and is still used on virtually every baby born today.
Blanket octopuses show one of the most extreme size differences between sexes of any animal on Earth: females can grow up to two meters long, while males stay smaller than a walnut. Males also carry a detachable mating arm that breaks off inside the female and keeps fertilizing her eggs after he's gone. Females are additionally immune to the deadly sting of the Portuguese man o' war and will rip off its tentacles to use as weapons.
— Wikipedia contributors, Blanket octopus — Tremoctopus sexual size dimorphism