Bay Area Skeptics

WHAT: How did the ancient Egyptians understand time, and how did they measure it? This lecture explores Egyptian timekeeping as both a science of observation and a religious way of organizing the cosmos. Drawing on objects from the collection of the Institute for the Study of Ancient Cultures Museum, including a water clock and an “astronomical instrument” associated with King Tutankhamun, Dr. Foy Scalf examines how Egyptians tracked the cycles of the sun, moon, stars, Nile flood, and seasons. Priests used star charts, shadow clocks, sundials, and water clocks to mark the hours of day and night, ensuring that temple rituals, festivals, agriculture, and funerary practices occurred at their proper moments. The talk also considers the famous claim of Amenemhet, an Egyptian official around 1500 BC who said he invented a device for measuring nighttime hours and asks what such claims reveal about ancient ideas of knowledge, technology, and discovery. Along the way, we will discuss differences between astronomy, astrology, science, and natural philosophy as we consider how Egyptian traditions relate to those of Mesopotamia, Greece, and the wider ancient Middle East.
WHO: Foy Scalf is Director of the Institute for the Study of Ancient Cultures Data Research Center and Research Archives Library at the University of Chicago. He is an Egyptologist whose work focuses on ancient Egyptian texts, religion, intellectual culture, and the transmission of knowledge in the ancient world. His research and public lectures often explore how ancient peoples understood the cosmos, organized knowledge, and used texts, images, and objects to make sense of human life, death, and the divine. He has curated exhibitions and published widely on Egyptian manuscripts, the Book of the Dead, and the history of Egyptology. At ISAC, he also works on digital research infrastructure, archives, and public access to ancient world collections.

WHEN: Thursday, Sept 10, 2026
WHERE: Online. www.bit.ly/BASscal