Name an advance made in science, technology, and mathematics during hellenistic times?

The Hellenistic Erasistratus discovered the heart was the pump to push blood through the arteries.

Aristarchus developed the theory that the sun was the center of the universe.

Euclid wrote the basic geometry book, Elements, that was used for 2000 years.

Hero of Alexandria devised the first steam engine although he considered it merely a toy.

During the Hellenistic period the sciences as a whole were separated from philosophy, which allowed a great advance in different fields of study. We can name the following events that occurred within this period:

 Eratosthenes de Cirene, librarian of Alexandria created the mathematical geography and was able to measure the length of the Earth's meridian. Hipparchus of Nicea spent much of his time observing the sky from his Rhodes observatory, where he was able to draw up a large map of the sky with more than 800 stars cataloged and studied by him. Regarding the health of people, the image of the magician disappears and the image of the Doctor is born. The health of the people is entrusted to the doctors and they enjoy a great reputation.