Eratosthenes (l. c. 276-195 BCE) was a Greek astronomer, geographer, mathematician, and poet best known for being the first to calculate the circumference of the earth and its axial tilt. He is also recognized for his mathematical innovation, the Sieve of Eratosthenes, which identified prime numbers, and his position as head of the Library at Alexandria.
https://www.worldhistory.org/Eratosthenes/ #Eratosthenes #GreekAstronomy #GreekMathematics

Eratosthenes (l. c. 276-195 BCE) was a Greek astronomer, geographer, mathematician, and poet best known for being the first to calculate the circumference of the earth and its axial tilt. He is also recognized for his mathematical innovation, the Sieve of Eratosthenes, which identified prime numbers, and his position as head of the Library at Alexandria.
https://www.worldhistory.org/Eratosthenes/ #Eratosthenes #GreekAstronomy #GreekMathematics

Ein kurzer #Schnappschuss vom #Mond. Die #Krater #Copernicus und #Eratosthenes.

A quick lunar #snapshot. The craters Copernicus and Eratosthenes.

#Mondfotografie #Lunarimaging #Astrofotografie #Astrophotography #Amateurastronomie #Amateurastronomy