Have you ever heard of the amazingandinspirational Carl Sagan?
Carl Sagan was an American astronomer, astrophysicist, cosmologist, author and science communicator. Why inspirational? Well, there are many intelligent beings in the world but not all of them are capable of communicating and appealing to the people like Carl Sagan did. Carl Sagan did this through his books and various media (The Cosmos being especially popular).
Why bring him up now?
Well, today, along with many other humans, Carl Sagan was born 78 years ago on November 9th 1934. So happy Carl Sagan Day!
“For small creatures such as we the vastness is bearable only through love.” - Carl Sagan.
“If you wish to make an apple pie from scratch, you must first invent the Universe”. - Carl Sagan.
“You’re capable of such beautiful dreams, and such horrible nightmares. You feel so lost, so cut off, so alone, only you’re not. See, in all our searching, the only thing we’ve found that makes the emptiness bearable, is each other.” - Carl Sagan,Contact
“To make this journey, we’ll need imagination, but imagination alone is not enough, because the reality of nature is far more wondrous than anything we can imagine.”
These are just a few of the beautiful visual effects from Cosmos: A Spacetime Odyssey
Aaaaah! Okay, it’s been awhile, but for good reason: NEWNESS. These are just a few of the new rubber stamps (based on some inked illustrations I worked on over the summer). Also. also. also. periodictableofelements stamp. in it’s freaking brilliant entirety (photos soon).
bipch erastosthenes schooled b.o.b. 2,230 years ago
Ok so this is cool but I always wondered how they knew the shadows were different at the same instant. I mean it is not like they had phones. How did they sync up that instant. I feel like that would be interesting to know but no one ever says.
^^^Does anybody know this one? How, that far apart, the time at which the shadows were observed was synced up? I am genuinely curious, not a goddamn moron asking a gotcha question. High/Low tide? (I live in the middle of the country I do not know for the precise habits of tidal activity.) The appearance of a star (or planet) in the sky? Something as utterly mundane as sunrise?
Well, first of all, it wasn’t actually pillars! Eratosthenes was told about a well in Syene that, in the summer solstice every year (June 21st) would be illuminated at the bottom entirely and without any cast shadows. This indicated that the sun was directly overhead. Going off that well known curiosity and an intelligent hunch, our dude Eratosthenes waited until high noon of the summer solstice to measure the angle of a shadow cast by a stick in Alexandria. (Sidenote: Eratosthenes was a librarian of the infamous Library of Alexandria.)
His next course of action was to hire bematists, surveyors of the time whose professional specialty was to measure distance by walking with equal length steps. They measured a distance between Alexandria and Syene of about 5000 stadia. (Guess where the word stadium comes from.) Once he had that measurement, Eratosthenes did his math-y thing, and there you have it.
ANSWER EVEN COOLER THAN I HOPED!!
Eratosthenes’ work was thorough enough that by the time he finished revising his calculations, he ended up only 66 km off of the actual polar circumference of the Earth, or an error margin of 0.16%. [wiki]
“It’s hard to understand how ‘conservatives’ could oppose safeguarding the environment that all of us—including conservatives and their children—depend on for our very lives. What exactly is it conservatives are conserving?”
