Several contributions of significance were brought forth by Greeks living in empire during the Greco-Roman era. Advancements in Astronomy included Ptolemy deepening our understanding that the planets followed circular orbits. His research on the cosmos was also cleaner than Aristotle’s and would go on to serve as the basis for Medieval European and Islamic cosmic understanding. A man of many interested, he also published a text on the science of Geography. Hypatia, credited as the first female natural philosopher, is said to have edited one of his works called the Almagest. Perhaps the most famous scientist of the time, Archimedes would go on to invent many practical devices with his knowledge of mathematics.
Similarly, there were also a number of reasons for the eventual decline of science and natural philosophy towards the end of the era. Overall there seemed to be a general loss of interest in applicable sciences as time went on since the days of Plato and Aristotle. Also worth mentioning is that it was not as sociable, which otherwise may have helped limit this decline through the continued sharing and proliferation of ideas. The rise of, and attacks by, religious cults throughout the period could also have helped stymy scientific growth. Finally, the death of Archimedes during the Roman invasion of Syracuse in 212 BC silenced a brilliant mind in a time where political turmoil and conquest increasingly overshadowed the pursuit of scientific knowledge.