Ancient Egyptian chronology and the astronomical orientation of pyramids

Nile waterscapes facilitated the construction of the Giza pyramids during the 3rd millennium BCE

The pyramids of Giza originally overlooked a now defunct arm of the Nile. This fluvial channel, the Khufu branch, enabled navigation to the Pyramid Harbor complex but its precise environmental history is unclear. To fill this knowledge gap, we use pollen-derived vegetation patterns to reconstruct 8,000 y of fluvial variations on the Giza floodplain. After a high-stand level concomitant with the African Humid Period, our results show that Giza's waterscapes responded to a gradual insolation-driven aridification of East Africa, with the lowest Nile levels recorded at the end of the Dynastic Period. The Khufu branch remained at a high-water level (∼40% of its Holocene maximum) during the reigns of Khufu, Khafre, and Menkaure, facilitating the transportation of construction materials to the Giza Pyramid Complex.

Mysterious Civilizations: Is There a Connection between Medicine and Architecture in Ancient Egypt and Peru?

The ancient Egyptian and Peruvian Civilizations are two of the earliest cultures in human history. Through medical and architectural similarities, we wish to show a possible connection between these two cultures. A literature search was conducted by searching the database of Medline, National Geographic magazine, history books, and Google Scholar using the search terms: neurosurgery, pyramids, pyramidal architectures, ancient Egypt, ancient Peru, the connection between ancient Egypt and Peru. Both the ancient Egyptian and Peruvian Civilizations are well-known for their pioneering work in medicine and architecture; their accomplishments in these areas have been well-documented in the walls of uncovered tombs and discovered papyrus. Both these cultures also firmly believed in an afterlife and built pyramids to serve as tombs and homes for royalty in the afterlife. The sloping sides of the pyramids were inclined to signify the emergence of the physical body from Earth towards the Sun. Both civilizations independently pioneered the art of neurosurgery with different techniques and approaches. In this paper, we discuss the potential links between both civilizations. We recognize and appreciate the brilliance of these ancient cultures in mastering the medicinal and architectural sciences.

Radiocarbon-based chronology for dynastic Egypt

The historical chronologies for dynastic Egypt are based on reign lengths inferred from written and archaeological evidence. These floating chronologies are linked to the absolute calendar by a few ancient astronomical observations, which remain a source of debate. We used 211 radiocarbon measurements made on samples from short-lived plants, together with a Bayesian model incorporating historical information on reign lengths, to produce a chronology for dynastic Egypt. A small offset (19 radiocarbon years older) in radiocarbon levels in the Nile Valley is probably a growing-season effect. Our radiocarbon data indicate that the New Kingdom started between 1570 and 1544 B.C.E., and the reign of Djoser in the Old Kingdom started between 2691 and 2625 B.C.E.; both cases are earlier than some previous historical estimates.

Ancient chronology. Astronomical orientation of the pyramids

Spence speculates that Egypt's pyramid builders found true north by using a plumb line: when the stars Kochab and Mizar were seen on the same vertical, one was facing north. As evidence in support of this hypothesis, she points to the proposed interstar-line precession past the north celestial pole at a rate of 27' per century (cy). We argue that a mathematical error affects this result, which when corrected points more strongly to a different pair of stars. This suggests that the conventional ancient chronology, instead of being compressed, may actually have to be expanded slightly.

Diffusion of astronomy in the ancient world

Astronomical techniques, calendars and devices were developed independently in many places around the world. However, there was much cross-cultural exchange of technology over the centuries. The cultures of Egypt, Greece, India and China influenced each others' astronomy and each cannot be treated in isolation.