Ancient Greek astronomers and early Islamic scientists used astrolabes as mechanical computers to calculate time, determine height and navigate by the stars April 29, 2026 10:07 a.m. The astrolabe weighs more than 18 pounds. Sotheby’s In the early 17th century, during the Golden Age of the Mughal Empire , two engineering brothers in present-day Pakistan created a prodigious brass astrolabe for a powerful nobleman. More than 400 years later, their intricate computer was auctioned by Sotheby’s in London, and it fetched some $2.75 million. Astrolabes, invented by Greek astronomers around 200 B.C.E., spread through the Islamic world by the eighth century. The device “reached its zenith in the hands of Islamic scientists,” according to a 2023 episode of NOVA by PBS. People used the circular instruments’ engraved, interchangeable plates to calculate heights, tell time and navigate by the stars.…