Cripple. History Major. Irritable and in constant pain. Vaguely Left-Wing.

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Joined 2 years ago
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Cake day: July 21st, 2023

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  • Explanation: Not only did the ancient Greek philosopher Eratosthenes (born and raised in what-is-now Libya) know the earth was spherical, he used that knowledge to measure the circumference of the earth - with two sticks and some carefully applied mathematical thought - to an astounding accuracy!

    According to Cleomedes’ On the Circular Motions of the Celestial Bodies, around 240 BC, Eratosthenes calculated the circumference of the Earth in Ptolemaic Egypt.[8] Using a vertical rod known as a gnomon and under the previous assumptions, he knew that at local noon on the summer solstice in Syene (modern Aswan, Egypt), the Sun was directly overhead, as the gnomon cast no shadow. Additionally, the shadow of someone looking down a deep well at that time in Syene blocked the reflection of the Sun on the water. Eratosthenes then measured the Sun’s angle of elevation at noon in Alexandria by measuring the length of another gnomon’s shadow on the ground.[9] Using the length of the rod and the length of the shadow as the legs of a triangle, he calculated the angle of the sun’s rays.[10] This angle was about 7°, or 1/50th the circumference of a circle; assuming the Earth to be perfectly spherical, he concluded that its circumference was 50 times the known distance from Alexandria to Syene (5,000 stadia, a figure that was checked yearly), i.e. 250,000 stadia.[11] Depending on whether he used the “Olympic stade” (176.4 m) or the Italian stade (184.8 m), this would imply a circumference of 44,100 km (an error of 10%) or 46,100 km, an error of 15%.[11] A value for the stadion of 157.7 metres has even been posited by L.V. Firsov, which would give an even better precision, but is plagued by calculation errors and false assumptions.[12] In 2012, Anthony Abreu Mora repeated Eratosthenes’s calculation with more accurate data; the result was 40,074 km, which is 66 km different (0.16%) from the currently accepted polar circumference.[10]
















  • Sherman, during the US Civil War, embarked on a march through the US South in which he destroyed infrastructure (especially railroads), seized food for his army to ‘live off the land’, and burned the personal property of enemy officials and rebels. He is remembered for his statement that he would “make Georgia howl” on his march (hence the title), and his campaign, wildly successful, left a deep cultural scar on the slaver plantation class in the South for generations to come.




  • I’m going to continue posting on dbzer0, personally. If it was just the matter of a mistake or a bad take, that would be one thing, but the admin’s behavior clearly indicates an attitude of hostility in his behavior as an admin towards people he considers ‘libs’, which, likewise, appears to be a very broadly applied label.

    The admin has every right to trim his community in such a fashion but that necessarily means that some people will not feel welcome. The Fediverse means an individual can choose communities on an instance where they feel welcome, or at least where they don’t feel like the sword of Damocles is hanging above their head. For me, that’s not Midwest.social at this point.