Wie kam Eratosthenes auf die Distanz 5000 Stadien?
Aus der Entfernung zwischen Assuan und Alexandria (= 5000 Stadien, das entspricht heute etwa 800 Kilometer, die der Gelehrte von einem Läufer genau vermessen ließ) und dem Einfallswinkel der Sonne (= 1/50 des Vollkreises) kam er auf einen Erdumfang von 50 mal 5000, also 250.000 Stadien.
Wann hat Eratosthenes gelebt?
276 v. Chr. – 195 v. Chr.
Eratosthenes/Lebensjahre
Wie hat man den Erdradius herausgefunden?
Wird für die Erdfigur näherungsweise eine Kugelform angenommen, kann der Erdumfang mittels der Umfangsberechnung für einen Kreis näherungsweise aus dem Erdradius berechnet werden: U = 2 π ⋅ r . Das ergibt bei einem Erdradius von 6.378 km einen Erdumfang von etwa 40.074 km.
Wie hat man den erdradius herausgefunden?
50 * (5000 * 157,5 m) = 39 375 000 m = 39 375 km lang sein. Eigentlich beruht die Bestimmung des Erdradius nach Eratosthenes auf der Grundlage des Winkels der sich zwischen dem Lot der Säule in Syene und dem Lot des Brunnenes in Alexandria ergibt.
What was Eratosthenes famous for?
Eratosthenes is famous for many things, including a mapping method that used latitudes and longitudes, and his accurate computation of the circumference of earth. To compute for the circumference of the earth, Eratosthenes used the principles of trigonometry and available data on the altitude of the sun in two specific locations at noontime.
What contributions did Eratosthenes make to science?
One of the main contributions of Eratosthenes to science and astronomy was his important work regarding the measurement of the earth . Eratosthenes, studying the papyri of the Alexandria library, found a report in which it was said that when the sun’s rays fall on a rod during the midday of the summer solstice no shade was produced.
What did Eratosthenes do?
Eratosthenes was a prominent Greek mathematician, astronomer and geographer who lived between 276 BC and 194 BC. He was born in what is now Libya, to parents who were probably Chaldean. Eratosthenes is famous for many things, including a mapping method that used latitudes and longitudes, and his accurate computation of the circumference of earth.
How Eratosthenes found the circumference of the Earth?
In 240 B.C., the Greek astronomer Eratosthenes made the first good measurement of the size of Earth. By noting the angles of shadows in two cities on the Summer Solstice, and by performing the right calculations using his knowledge of geometry and the distance between the cities, Eratosthenes was able to make a remarkably accurate calculation of the circumference of Earth.