Culture is part of the unholy trinity—culture, chaos, and cock-up—which roam through our versions of history, substituting for traditional theories of causation. – Filipe Fernández–Armesto "Pathfinders: A Global History of Exploration"

"As by his claw, we know the lion."

Gottlob Frege (1848-1925) was a German mathematician who didn't invent mathematics, but did invent modern predicate logic and quantified variables -- the language of mathematics in his 1879 book, Begriffsschrift. -> wikiwand.com/en/Gottlob_Freg…

100 years ago, Tait et al argued for quaternions and Gibbs argued for vectors, vectors won out. --> fexpr.blogspot.com/2014/03/t…

The volume on medicinal alchemy that I have coedited with Lawrence M. Principe is finally heading to press. ⚗️Medicinal Alchemy, 1250-1700: Origins, Theories, Practices or ⚗️Making Medicines: Aspects of Alchemy and Healing, 1250-1700? Which is your favorite title? 🔥🦎🙏

June 13, 1911, birthday of physicist Luis Walter Alvarez (1911-1988). He worked on the first A-bomb. In more peaceful times he developed - together with his son Walter Alvarez - the end-Cretaceous "impact-theory" to explain the mass extinction 65 million years ago 🦖☄️

Internet: Medieval people didn't care about filth & bad smells and their castle latrines dumped human waste where people walked. The Kwidzyn Castle architect: Yeah but no, let's build a special tower with a bridge for the toilets over the river!

Vance displaying his ignorance as per usual

The crowd at the White House UFC fight will be one of the most diverse ever. There will be convicted felons, rapists, pedophiles, sex traffickers, domestic abusers and insurrectionists.

Johann Fabricius published the first book on the telescopic observation of sun spots on 13 June 1611 #histsci thonyc.wordpress.com/2011/01…

#FossilFriday E. Stromer von Reichenbach, German palaeontologist who discovered #Spinosaurus, was born on June 12, 1870 wp.me/p3ihHu-vk #histsci ⚒️🧪

“Andrea Wulf’s magnificent book … George’s efforts to adapt to life and work at sea, as laid out in “The Traveler,” are as exciting as anything in the pages of Robert Louis Stevenson” – John Banville in the Wall Street Journal wsj.com/arts-culture/books/t…

“Wulf’s biography is filled with marvellous details …this is a fascinating book about a fascinating life” – Financial Times ft.com/content/e902b6d2-f7f5…

🚨EXCLUSIVE: A commercial airline pilot tells MeidasTouch they filed FAA and NASA safety reports after lighting from Trump’s UFC event at the White House allegedly flooded their cockpit on approach to Reagan National. The pilot called it “10 times worse than any laser illumination event” they’d ever experienced. meidasnews.com/news/white-ho…

Around 240 BCE, Eratosthenes of Cyrene produced one of the most remarkable measurements in the history of science: he estimated the circumference of the Earth using sunlight, shadows, geometry, and the known distance between two Egyptian cities. He had heard that in Syene, near modern Aswan, the Sun shone almost directly overhead at noon on the summer solstice, illuminating the bottoms of deep wells and leaving little or no shadow. At the same moment in Alexandria, farther north, a vertical stick, or gnomon, did cast a shadow. That difference was the key. In Alexandria, Eratosthenes measured the relation between the height of the gnomon and the length of its shadow. From that right triangle, he deduced that the Sun’s rays there made an angle of about 7.2 degrees from the vertical, equivalent to one fiftieth of a full circle. Since sunlight reaches Earth from such a great distance that its rays are effectively parallel, the angle measured in Alexandria could be interpreted as the angle between Syene and Alexandria at Earth’s centre. If the distance between the two cities represented one fiftieth of a full circle, then Earth’s total circumference had to be fifty times that distance. Eratosthenes multiplied the estimated distance from Syene to Alexandria by 50 and obtained a value of about 250,000 stadia. The exact modern equivalent remains debated because the ancient stadion was not a single fixed unit, but his result was still remarkably close to the true circumference of Earth. The importance of the calculation lies not only in the numerical result, but in the reasoning behind it. Eratosthenes transformed a local observation, the length of a shadow in one city and the reported absence of one in another, into a measurement of the entire planet. Without telescopes, satellites, or modern instruments, he showed that the size of Earth could be inferred through careful observation and geometry. It remains one of the clearest examples of how science can reveal a global truth from simple, ordinary evidence.

Yup

"This Sunday night’s UFC spectacle on the South Lawn...captures something about this moment in our history. It's vulgar, violent, commercial, grandiose, tacky, and it dishonors a place once thought worthy of care and respect. In other words, it’s Donald Trump." open.substack.com/pub/thebul…

I really recommend reading this excellent paper by Dr Mehdy Shaddel, which puts this old canard to bed and demonstrates that non Muslim sources do not in fact contradict the traditional death date for the Prophet. Its central argument also has much wider implications for how scholars should approach the periodisation of early Islamic history, in order to prevent such misinterpretation of sources from arising in the first place.

All the sensible people on Earth would beg the aliens to keep you

Have you ever wondered what major discoveries were made in mathematics exactly 100 years ago? This webpage answers. mathshistory.st-andrews.ac.u…