Kevin C. Abblett
Reevaluating the Legacy of Egyptian Astronomy
The last of the Great Wonders of the World, the great pyramid of Cheops at Giza, is built along an ancient prime meridian that miraculously is even more precise than our own modern achievement in Greenwich observatory today. It is so perfectly aligned in fact, that if one were to strike out from its eastern face and trace a path north, one would reach True North at a point not farther than roughly 3’6” off center (Schoch/McNally). Add this to the discovery of the Tropical year to the precise measure of 365 ¼ days, which Egypt had mapped as early as 5,000 years ago, and one has a strong case for an advanced mathematics that stretches back to the very dawn of civilization. It is curious then, that even when “the genuine accomplishments of the Egyptian astronomers . . . are recognized, we still find them relatively unappreciated by historians of science” (Krupp). Two scholars exemplify these divergent theories: Sir Norman Lockyer, writing in the late nineteenth century, who first hypothesized the presence of advanced mathematics in the orientation of ancient temple structures, and Otto Neugebauer, who wrote nearly a half-century later and argues against the existence of advanced mathematics in any but the centuries comprising the first millennium BC. Lockyer’s work suffers from the stigma of centuries of esoteric speculation on Egypt, coupled with a speculative approach and “in some cases wrong, remarks about Egyptian history and culture [that] led many prominent Egyptologist to dismiss his work” (Krupp). Neugebauer, on the contrary, is able to demonstrate that in the surviving texts of the ancient world, “no systematic and comprehensive observation of the sun, moon, planets, and stars . . . remains.” In spite of this lack of evidence, however, there were astronomers in ancient Egypt. Their legacy lies scattered along the Nile valley in their remaining megaliths and in the endurance of their calendar for more than 5,000 years. (Krupp). Neugebauer argues that the development of predictive astrology in late-Babylon is the source for the development of mathematics and science for the Greeks and, subsequently, our modern world and allows for little to no cross pollination from Egypt. Until recent years, it has proven impossible to refute his claims, but new research has revealed a fundamental flaw in Neugebauer’s conclusions that have opened the door for a much needed reevaluation of Sir Lockyer’s hypothesis and the accompanying stellar accomplishments of ancient man.
Sir Lockyer’s thesis was born from a chance observation of the Greek Parthenon. Borrowing a compass from a friend, he was struck by the precision with which the Temple was aligned along the cardinal points of the Earth and conjectured that such a technical skill must have come from some more ancient technology. In Lockyer’s time, Egypt was viewed as the source of much if not all of the scientific and mathematical knowledge of the ancients, and he hypothesized that “[t]he determination of the stars to which some of the Egyptian temples . . . were directed, opened a way . . . to a study of the astronomical basis of parts of [their] mythology” (Lockyer). Missing data, and needing to corroborate his thesis against observable facts, he traveled to Egypt to take more detailed readings of the alignments of certain temples because “when the orientations were [originally] observed and recorded, it was not known what use would be made of them” (Lockyer). At sites like the Temple of Isis at Dendera, he observed “an alignment with the star Sirius” (Krupp). Finding similar data with several additional sites, Lockyer concludes that Egyptian mythology, and thus religion, “was intensely astronomical, and crystallized early ideas suggested by actual observations of the sun, moon and stars” (Lockyer). His hypothesis suggests that the Egyptians “oriented their temples astronomically and used them as observatories and as ceremonial centers for significant celestial events.” Lockyer believes that the Egyptian temple structure was “designed around a long passage . . . arranged to permit a beam of light from the sun or other celestial object to reach all the way down the passage to a darkened sanctuary [at its limit].” He believes that this passage would allow for “the chamber [to be] illuminated for only a few moments on just the right day.” His calculations then argue that this “would have allowed the Egyptians to estimate the length of the tropical year to one minute’s precision, or one ten-thousandth of a year” (Krupp). Lockyer’s conclusion was that “it is impossible to doubt [in light of this new evidence] that these structures were erected by a people possessing much astronomical knowledge” (Lockyer). E. C. Krupp, an astronomer and author working out of Griffith Observatory notes that “[a]lthough it is possible that the temples were used as Lockyer described . . . his system of alignments is difficult to confirm in detail. His arguments are incomplete, and until a comprehensive picture of practical Egyptian astronomy is available . . . the case will remain unresolved.” He notes, however, that it “seems likely that his approach . . . and his evaluation of Egyptian astronomical endeavor are destined for a rebirth” (Krupp).
One of the key difficulties with Lockyer’s hypothesis has to do with the effects of precession, an astronomical phenomena that causes the regular appearance of stars along the belt of the ecliptic to slip or “fall back” below the horizon at a speed of roughly 30° every 2,200 years. This means that a stellar alignment would only work for “a few centuries . . . and a temple aligned precisely on a particular star would become useless” and would need to be continually realigned. Lockyer points out that “[i]n fact, such reconstruction [does] occur . . . [and that] four additions to the temple at Luxor, each of which deviates slightly from the previous orientation [can be observed]” (Krupp). Precession as a phenomenon was not articulated until after 300 AD, well into the Hellenistic period, when Hipparchus of Alexandria “noticed that every one of the longitudes of stars recorded by the Babylonians [was] less than what he had observed . . . and rightly reasoned that the Babylonian figures would not all have been in error. The skies had shifted” (Sellers). This late discovery of precession seems to argue against Lockyer’s hypothesis, but Giorgio Santillana, historian of Science at MIT, in his controversial book Hamlet’s Mill, argues that knowledge of precession predates Hipparchus’ “discovery” by more than 2,000 years, and that the key to unlocking Egypt’s and other ancient people’s knowledge of the stars lies in the interpretation of myth in line with astronomical phenomena. He argues that “[t]he sun’s position among the constellations at the vernal equinox was the pointer . . . of the precessional cycle” and goes on to argue that, in the time before civilization began, “the sun was in [the constellation] Gemini; it moved . . . from Gemini into Taurus, then Aries, then Pisces, which it still occupies [today].” In support of his mythological and religious hypothesis, he demonstrates that “[t]he preceding age . . . [of] Aries, had been heralded by Moses coming down from Mount Sinai as ‘two-horned,’ that is, crowned with the Ram’s horns [of Aries], while his flock disobediently insisted upon dancing around the ‘Golden Calf’ . . . [or] ‘Golden Bull,’ [of] Taurus.” He also notes that “[t]he advent of Christ the Fish marks our [current] age [of Pisces].” (Santillana/Von Dechend). This hypothesis stands squarely in the face of the consensus of modern scholarship. E. C. Krupp points out that “[c]omprehensive knowledge of precession seems to be incompatible with the descriptive non-mathematical picture of astronomy” offered by Otto Neugebauer” (Krupp). Neugebauer, however, “a very vocal opponent of the idea that ancient Egyptians possessed an ‘ancient science’ had conceded that ‘For ancient astronomy, precession required nothing more than sufficiently remote and sufficiently reliable records of observations of positions of fixed stars’” which do in fact exist, quite abundantly in the archeological record (Sellers).
In his Exact Sciences in Antiquity, Neugebauer states that the ancient Egyptians possessed a calendar that is “the only intelligent calendar which ever existed in human history.” He states that this calendar of 365 total days, “originated on purely practical grounds, with no relation to astronomical problems.” He points out, however, that eventually, this calendar would be beneficial to the later astrologies of the Babylonians and Greeks (Neugebauer). “By 2100 BC [the Egyptian Middle Kingdom], thirty-six star gods had been set in relation to this civil calendar and these gods of the heaven appeared on coffin lids” (Sellers). Neugebauer, in his monumental study, The Egyptian Astronomical Texts, co-authored with R. A. Parker, examines the evidence of these coffins and finds no traces of the type of mathematics or observations that would allow for their calendar being derived by stellar means. E. C. Krupp concurs that “from the evidence that is available, Egyptian astronomy was inferior to its Babylonian counterpart . . . [and] for the present nothing comparable to the systematic, mathematical astronomy . . . [of the Babylonians] is known” (Krupp). In assessing these claims, it must be kept in mind that the majority of these astronomical inscriptions come primarily from Thebes in the south of Egypt, where it is likely that “the archeological record . . . may be distorted” (Quirke). Thebes was modeled after the Northern city of the sun, Iunu, or Heliopolis to the Greeks. During the period of the 21st and 22nd Dynasties, a few fragments of these types of star-filled coffin inscriptions exist in Northern territories, but they date from a very late period in Egypt’s history. Northern Egypt was home to Iunu, the Cult of the Sun God Ra and was the birthplace of Egypt’s calendar and time-keeping systems. It lies within the moist, fertile plain of the Nile delta, in contrast to the dry, arid climate of Thebes in the south, and it is likely that “[i]f the royal Delta cities ever produced any [stellar] coffins or papyri of their own, such organic material could not have survived in the damp soil” (Quirke). The majority of the remains of Heliopolis, and thus the great center of Egyptian celestial observation, lies in ruins beneath the city of modern-day Cairo. Until a full survey of this buried metropolis is completed, it’s likely that questions about its observational history will remain unanswered (Quirke).
In addition to their civil calendar, another contribution to the development of astronomy was the Egyptian’s “division of the day into 24 hours” (Neugebauer). This division is based upon the celestial observation of 36 decans, a Greek word for 10 representing the 36 stars that in the Egyptian New Kingdom, heralded the corresponding 10-day weeks of their year. Though in the earliest attested examples the Egyptians used a heavily flawed Lunar calendar, it appears that near the start of their civilization, they abandoned this and instead “counted the days between [the] successive heliacal risings of [the bright star] Sirius, a system, it is suggested, that led to a year 365 days long” (Sellers). The heliacal rising of a star is the period in its annual orbit when it is seen to rise near the sun, in the moments just before dawn, and disappears just as the sun breaches the horizon. Neugebauer, as I will demonstrate, mistakenly asserts that these heliacally rising decans “have left no traces in modern astronomy.” He finds this curious, however, since the decans “are the actual reason for the 12-[hour]-division of the night and hence . . . of the [whole] 24-hour system” (Neugebauer). The decans first appear on the same Middle Kingdom coffin lids attested above. Of these 36 decans, to date “[o]nly two can be directly identified, namely Sirius and Orion” (Neugebauer). E. C. Krupp states that “[t]he Egyptians considered the heliacal rising of Sirius to be so important that they marked the beginning of the new year by this event. Even more compelling was the fact that the heliacally rising Sirius and the rising Nile coincided, approximately, with the summer solstice” (Krupp). The rising of the Nile in Egypt was more than any other single event, the evident life-blood of the land that yearly renewed the harsh desert and brought life and prosperity to its devout people. “The pattern of Sirius at the summer solstice became the plan for the entire year [and] for all of the decans [that followed it].” (Krupp).
In assessing the evidence of the star-inscribed coffins of the Middle Kingdom, Neugebauer mistakenly concludes that the pattern of Egyptian decans was abandoned by the later developments of Babylonian and Hellenistic astrology. He examines two primary Egyptian texts that describe the patterns followed by all decan stars. One is a New Kingdom “cenotaph [or false tomb] of Seti I [describing] at length how one decan after another ‘dies’ . . . [and] is ‘purified’ in the embalming house of the nether world, to be reborn after 70 days of invisibility” (Neugebauer). The other is the Roman-era Carlsburg papyrus which “tells us that Sirius sets the pattern of behavior for all the decan stars by doing four things over the course of a year. It is ‘first,’ then 90 days later, it is ‘šn dw3t.’ 70 days after that, it is ‘born.’ 80 days after that, it ‘works’ or ‘serves.’ Then, 120 days later, it is back to ‘first.’” Based on observations of Sirius’ annual pattern, Neugebauer then notices that it “disappears from the sky for roughly 70 days following its heliacal setting . . . [and assumes] that the 70-day period that stars are said to be šn dw3t refers to [this] period of invisibility.” Though this hypothesis seems reasonable in theory, in practice, it “posits a pattern that no stars fit” (Conman). Due to this inability of his model to reveal the identity of any accompanying decans related to Orion and Sirius on the Middle and New Kingdom star-coffins, Neugebauer asserts that “[t]o attempt to go further in the determination of the decans is not only of very little interest but would necessarily imply ascribing to our texts an astronomical accuracy which they were never intended to have,” effectively dismissing the stellar observations of the ancient Egyptians as nothing more than a “sound, however primitive, procedure of marking time at night by means of stars” (Neugebauer).
Joanne Conman, writing just a few years ago, revisited these conclusions of Neugebauer’s and discovered that his “model does not and cannot match the pattern required by the . . . [coffin star maps]” (Conman). She argues that by utilizing the information provided in the cenotaph of Seti I and the Carlsburg papyri, “one should be able to find stars that were observable at some time and place in Egypt” and put them into one of the many star-maps that have been found in the archeological record (Conman). Applying Neugebauer’s model of the decans to these maps proved conclusively that a fundamental flaw existed in his conclusions. Conman then demonstrates that, because of this “erroneous theory, Neugebuer and Parker failed to recognize the decan system’s assimilation directly into Hellenistic astrology” (Conman). She abandons Neugebauer’s model completely and takes a different approach to understanding the decanal lifecycle. Realizing that the heliacal rising of Sirius was a cornerstone of Egyptian religious life, she posited this phenomena as one of the four key decan events and not the 70 day disappearance of Sirius that Neugebauer postulated. Remarkably, this new approach reveals a pattern of observations that satisfies both the Carslburg and earlier Seti star-maps both at different times and locations throughout Egypt’s vast history (Conman). The implications of this discovery allowed for her to observe a pattern of decanal behavior that offered an explanation for one of the oldest, and most obscure, points in Greco-Babylonian astrology: the exaltations, or “places of power” of the planets along certain points of the ecliptic. At certain points along a planet’s regular orbit, it hits a particular point of maximum power or influence upon the earth. In Babylon, this point was located in the general region of a constellation, whereas in Greece, it was found in a specific degree of the ecliptic itself. These phenomena have long been understood as Babylonian inventions, carried forth into the astrologies of the later Greeks and Arabs. Conman’s new approach demonstrates that these exaltations are “very likely the result of ideas adopted from the Egyptians” and that they predate their Babylonian counterparts by over 1,000 years. (Conman). She finally notes that, “it would be an extraordinary coincidence [if] the Babylonians just happened to choose a pattern . . . [that matches] the Egyptian decans so closely” (Conman).
Conman’s study is still relatively new, and the full implications of her findings will likely take decades to fully infiltrate the archeological community, which is still heavily indoctrinated by the towering figure of Neugebauer. The past seventy years of scholarly research have been guided by the notion that Egyptian astronomy, if it existed at all, had little or no effect on the scientific approaches of the Babylonian and Hellenistic periods. This assertion has been severely crippled by this new discovery, and claims, like those of Sir Norman Lockyer from more than a century past, that the Egyptians possessed a sophisticated and articulate knowledge of the movement of the heavens, deserve to be reexamined in the light of this new evidence. The time has again come for questions about the stellar knowledge of the ancient Egyptians to be allowed entrance into the great debate over the scientific and mathematical legacy of the ancient world. As the picture of the far ancient skies continues to unravel before us, it is essential that we remain open to the possibility that our so-called knowledge of how our world evolved is incomplete and ever-changing.
Conman, Joanne. “The Egyptian Origins of Planetary Hypsomata.” Discussions in Egyptology 64. 2006-2009. Academia.edu. Web. 7 Mar. 2015. Online.
Krupp, E. C. In Search of Ancient Astronomies. Garden City,: Doubleday, 1977. Print.
Lockyer, Norman. The Dawn of Astronomy; a Study of the Temple Worship and Mythology of the Ancient Egyptians. Cambridge: M.I.T., 1964, Print.
Neugebauer, O. The Exact Sciences in Antiquity. 2nd ed. New York: Dover, 1957. Print
Quirke, Stephen. The Cult of Ra: Sun-worship in Ancient Egypt. New York: Thames & Hudson, 2001. Print
Santillana, Giorgio, and Von Dechend, Hertha. Hamlet’s Mill; an Essay on Myth and the Frame of Time. Boston: Gambit, 1969. Print.
Schoch, Robert M., and McNally, Robert Aquinas. Pyramid Quest: Secrets of the Great Pyramid and the Dawn of Civilization. New York,: Jeremy P. Tarcher/Penguin, 2005. Print.
Sellers, Jane. The Death of Gods in Ancient Egypt: An Essay on Egyptian Religion and the Frame of Time. London: Penguin, 1992. Print.