by NADER HABIB
Eratosthenes. Image/Wikipedia
On 21 June this year it was time for the Bibliotheca Alexandrina to measure the circumference of the earth. A re-enactment of the original feat, carried out by Eratosthenes (b 276 BCE), third director of the original Alexandria Library in antiquity, for the past nine years, the Bibliotheca has been inviting students to attend the re-enactment that is held each year on the summer solstice. This year, nearly 450 people gathered for this day of scientific celebration, organised by the library’s Planetarium.
Sitting in a hall full of teenagers, one expects random noise and spontaneous energy. But not this time. As Shaymaa El-Sherif, unit chief of the francophone library at the Bibliotheca, took the podium you could hear a pin drop. Her presentation of this almost incredible piece of scientific research was so riveting that the middle-school students listened in silence, as if in a trance.
El-Sherif wrote her PhD thesis about the world view of Eratosthenes as seen in fiction. In her lecture, she mentioned that Eratosthenes was born in Cyrene, in today’s Libya, in 276 BCE. Cyrene at that time was almost as well-known as Alexandria or Athens. He studied in Athens and then settled in Alexandria to teach and research.
Shedding light on Alexandria’s history, El-Sherif noted that Alexander the Great did not build Alexandria. Instead, the architect Dinocrates did so on the orders of Ptolemy I, who ruled Egypt after Alexander’s death. A student of Aristotle, Ptolemy prided himself on patronising science and scientists, and when he acceded to the Egyptian throne he asked Straton of Lampsakos, a prominent scientist with encyclopaedic knowledge, to teach his son.
The son grew up to take the name of Ptolemy II Philadelphus, or “lover of his sister”. A statue of Ptolemy II stands at the Bibliotheca’s entrance on Port Said Street in Alexandria in recognition of his role in establishing the original library. For tutoring his son, Ptolemy I rewarded Straton with 80 talents, or the equivalent of two tonnes of silver.
Ptolemy II was just as passionate about science as his father, and it is he who put the final touches to the ancient library. His son Ptolemy III Euergetes (his name means “good-doer”) is the one who hired Eratosthenes. Impressed by what he heard of the latter’s brilliance, Ptolemy III offered the young scientist, living in Athens at the time, the chance to become resident scientist in Alexandria and tutor to his son. The latter would later rule under the name of Ptolemy IV Philopater (his name translates as “father-loving”).
In 245, Eratosthenes, still in his early 30s, became a scientist at the mouseion, Alexandria’s Temple of the Muses, which was also the city’s top institution of learning and included the famous library. It was a high-ranking job with many perks, including unfettered access to the royal family.
Before long, Eratosthenes became the mouseion’s most important scientist, and, when Apollonius of Rhodes, second director of the library died shortly afterwards, Ptolemy III issued a decree appointing Eratosthenes in his place. It was a position that Eratosthenes kept for 40 years. According to El-Sherif, Eratosthenes owed his long tenure to his tendency to steer clear of politics and focus on his work and research.
Eratosthenes coined the word geography, which he would have pronounced geographicus. He is also credited with drawing up the first map of the earth, which he based on information available in Alexandria at the time. He considered cartography, or the science of mapping, to be an independent branch of knowledge, and he drew a full map of the River Nile, an achievement that brought him considerable criticism from his contemporaries as during his time the Nile was thought to originate not on earth but in heaven.
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