Origins of the Sphinx: Two Clocks, One Monument, and the Core Nobody Has Drilled

THE BOOK

Origins of the Sphinx: Celestial Guardian of Pre-Pharaonic Civilization, by Robert M. Schoch, Ph.D., and Robert Bauval, Inner Traditions, Rochester, Vermont, 2017, paperback original, 528 pages, the edition read for this review. A preface, seven chapters written in alternating voices and each signed by the man who wrote it, an epilogue, and nine appendices that take up close to two fifths of the book: among them Schoch’s 1992 KMT paper reprinted with his 2016 corrections set inside it in brackets, his reply to the critics written in 1999 and 2000, and Breasted’s 1906 translation of the Dream Stela.

The most useful thing in this book is a missing object. Between the paws of the Great Sphinx stands the granite stela Tuthmoses IV set up around 1400 BCE, and on its thirteenth line, since 1842, Egyptology has read the name of Khafre. That line is the only ancient text ever offered to connect the monument to the king, and the cartouche is not there any more. It was drawn by Henry Salt at the time of Caviglia’s clearance, copied from Salt by Thomas Young and again for Vyse’s 1842 volumes, and pressed in paper by Lepsius the same year; the copies disagree with each other, no photograph of it has ever been found, and the sign that completes the name, the sun disc that turns “Khaf” into Khafre, is a restoration rather than a reading of the stone. The earliest reading in print, Samuel Birch’s note on the tablet in Vyse’s volumes, already gives the cartouche as “the prenomen of the king Ra-shaa-f, or Shafre,” and warns in the same sentence that “the fracture in the inscription makes it impossible to determine in what manner the name is mentioned.” The book credits Birch with supplying the disc; other accounts credit Young; the stone itself no longer says. Selim Hassan, who excavated the Sphinx in the 1930s, put it more bluntly in 1949: excepting that line, “which proves nothing, there is not one single ancient inscription which connects the Sphinx with Khafre.” Chapter three of this book walks you back through that chain, copy by copy, and it is the part of the argument that requires no geology and no astronomy at all. You can check every step of it, and the step that matters holds.

Two men wrote this book, in alternating chapters, each signed, and the design is the first thing I liked about it. Robert Bauval is an engineer who says in appendix one that he has “no Ph.D. to my name,” who first published the Orion correlation in the Oxford journal Discussions in Egyptology in 1989 and then in The Orion Mystery in 1994, and who writes the textual, historical and astronomical chapters here. Robert Schoch is a geologist with a Yale doctorate who has taught at Boston University since 1984, in its college of general studies rather than its earth sciences department, a detail the book leaves to a footnote and a passing phrase, which his critics have used, and which changes nothing about the shape of a weathered rock; he writes the excavation history, the geology and the appendices that carry the technical load. They have been friends for many years, the idea for the book came over a meal in the Rhodope Mountains in July 2014, and the preface promises the reader “not only our analyses and conclusions, but also much of the essential data and the conceptual tools to come to your own conclusions.” Most books in this genre make that promise. This one keeps it, which is why it can be argued with, and why it is worth arguing with.

The attribution the book is arguing against turns out to have a history, and the history is longer than the book says. Bauval dates it to 1908, when George Reisner, having excavated Menkaure’s temples, renamed the granite building beside the Sphinx the Valley Temple of Khafre by analogy and reasoned that whatever stood next door to a Khafre temple must be Khafre’s; Cosmopolitan announced in 1912 that an American professor had solved the riddle. His sentence on that step is fair: Reisner argued by proximity “even though there was no archaeological evidence to support this conclusion. Yet Reisner’s speculative conclusion is still unequivocally accepted as fact.” But the proximity argument is not Reisner’s. Auguste Mariette uncovered the granite temple in 1853, and the diorite Khafre that anchors the whole attribution came out of a pit in its floor in 1860; Petrie’s History of Egypt of 1894 was already calling the building “often misnamed the temple of the Sphinx”; and Birch’s 1842 note, the one the book quotes for its warning about the fracture, continues in the next sentence with the inference itself: “the Sphinx is situated before the eastern front of the ruins, supposed to have been a temple connected with the second Pyramid, which is said to have been built by Chefren.” Bauval prints the first half of that paragraph and not the second. That makes the attribution an inheritance sixty-six years older than his chapter allows, and less any one man’s guess; it does not make it evidence, because at every link the argument is the same one, from position. Others inside the field have said as much. Rainer Stadelmann, who thinks the face is Khufu’s, wrote in 2000 that “very often in our discipline, old and seemingly certain statements rest forever without further verification,” and Breasted in 1906 called the step from the stela to authorship “a conclusion which does not follow.” None of those men is a lost-civilisation writer. What the chapter establishes, once its dates are corrected, is not that the Sphinx is old but that its date was never demonstrated, only inherited, and the two are different claims with very different burdens.

Then the rock, which is where I think the book earns its cover. Rain and wind-driven sand degrade limestone differently. Wind picks out the soft beds and leaves an angular, stepped profile with a varnish on the hard layers; rain and runoff leave “a rolling and undulating surface profile, giving the rock in some cases a coved appearance,” with vertical fissures that open wider at the top than at the bottom. The walls of the Sphinx enclosure show the second pattern, deepest at the western end, which is where water coming off the plateau would have arrived first. The Old Kingdom tombs south and west of the Sphinx, cut from the same sequence of limestones, show the first. That control case is the whole argument in one photograph, and the counter-explanations that have been published, salt exfoliation, wet sand, flash floods, groundwater, are all attempts to make the second profile by some other route; appendix seven takes them by name, Gauri, Harrell, Yurco, Lawton and Ogilvie-Herald, and quotes each at length before replying. The two temples in front of the monument carry the same evidence in a different form: their limestone cores were quarried out of the enclosure, and the granite ashlars fitted to them were cut with irregular backs to sit against faces that had already weathered, which makes no sense if the cores were fresh when the granite went on. Schoch adds the caveat himself, that “the attribution of the granite ashlars to the time of Khafre is itself circumstantial,” and I am inclined to trust a man who volunteers the sentence that weakens his own dating.

The measurement that is new is the seismic one, and this book is the fullest account of it in print. In April 1991 Schoch and the geophysicist Thomas Dobecki ran four refraction lines around the body of the Sphinx, a five-kilogram sledgehammer on a steel plate and twenty-four geophones, all four lines on the same limestone member that floors the enclosure. On the north, south and east sides the weathered layer under the floor runs 1.8 to 2.5 metres deep; behind the rump it runs about 1 to 1.2 metres. “These results were completely unexpected.” The reading Schoch gives is that the body was not freed from the bedrock in one campaign: the flanks and front were cut down first, the rear still merged with the rock, and the rump was finished later, plausibly in the Old Kingdom. The same survey found a rectangular low-velocity anomaly under the left paw, about twelve metres by nine, and a buried cliff east of the Sphinx Temple that would once have made the whole complex a terrace above the valley.

The 1992 paper converted the depth ratio into a date by simple proportion, fifty to a hundred percent older than the western floor, and got 7000 to 5000 BCE; the 2016 bracket inside the reprint says “I now believe I severely underestimated the age of the original structure,” because weathering slows as it deepens, and the calibration in chapter two now reaches “circa 10,000 BCE (or even a bit earlier).” I will come back to what that conversion assumes. The point to make here is that this is a real dataset, with its velocities and depths printed, published in Geoarchaeology at the time, and the reading it invites has never been checked by the obvious means. Holes have gone into that floor over the decades, for conservation and to test the groundwater, and by the excavators’ own account in 2024 most of what came out of them is unpublished; the core that would read the weathered layer as a clock, taken on all four sides, characterised and dated, has not been drilled, or if it has, no one has said so. Harrell said as much in 2000, and the book quotes him saying it: “He has not dug or drilled into this layer and so has no idea of what is really down there.” Schoch’s own bracket, at the end of the reprinted paper’s list of the tests he wanted to run, reads: “Unfortunately, as of 2016, none of this work has taken place.” Nine years on it still has not, and I find that more remarkable than anything either side has said in the meantime.

Bauval’s sky is the other clock, and it is the part of the book I hold at a greater distance. His chapters five and six make a chain: the two names the New Kingdom used for the monument, Horemakhet and Horakhti, “Horus in the horizon” and “Horus of the horizon,” read as a statue and its celestial twin; the stelae that show two sphinxes back to back, one facing east and one west; the first of Tybi falling one hundred and twenty-one days after the summer solstice, when the sun rises at azimuth 104 degrees, which is the bearing of the Khafre causeway; and the Sphinx’s due-east gaze, which fixes it to the equinoxes and therefore, if the lion in the sky is Leo, to the Age of Leo and to around 10,500 BCE, when Orion’s belt also sat at the bottom of its precessional trough and matched the three pyramids. It is elegant, it is a chain, and every link is a choice among readings. Bauval knows this, and says so in the sentence that matters most in his half of the book: “the connection of the Great Sphinx with the epoch of 10,500 BCE or any other older date cannot be proved only by astronomy. So this is as far as the OCT can take the investigation.”

Our own Precession and Orion Correlation bench reproduces both sides’ numbers, Bauval’s belt altitude at the trough and Fairall’s fifty degrees against Petrie’s thirty-eight, and it also shows what appendix two concedes in a box, that the same fit holds from about 9500 to 11,500 BCE: the trough is flat, the belt stays within a quarter of a degree of the bottom for about a thousand years down there, so the sky picks out an epoch, not a date. Appendix one, the account of the 1999 BBC programme and Krupp’s “you have to turn Egypt upside down,” is the least good thing in the book, twenty-odd pages of grievance in which the Broadcasting Standards Commission’s partial finding in Bauval’s favour sits beside its finding that the programme-makers acted in good faith, and only one of the two gets the emphasis. A reader who opens the appendices at that page will not reach the geology, which would be a pity, because the geology is where the book lives.

What I like most is how much of its own working the book shows. Appendix six reprints the 1992 KMT paper as it stood, with the 2016 second thoughts inside it in brackets, so you can watch the estimate move from the fifth millennium to 7000 to 5000 BCE to before the end of the last ice age, and read the reasons given at each step. The 1992 text says “I do not claim to have the ‘truth’, but simply to present a testable hypothesis relative to the age of the Sphinx. I am willing to see my explanation proven wrong on the basis of evidence outweighing the evidence which corroborates it.” Appendix seven says “I am not adamant about these dates whatsoever. For me, the important issue is whether or not the Sphinx is pre-Old Kingdom.” Those are the sentences of someone who expects to be checked. The head is conceded outright as a dynastic recarving, too small for the body, and the book is content for the face to be Khufu’s or Khafre’s because “one such king remodeled the original face of a lion.”

Appendix nine does the thing I least expected: it spends its central pages dismantling the Younger Dryas impact hypothesis, the comet that would have handed the authors their catastrophe ready-made, and concludes that “the evidence collectively points away from an extraterrestrial impact for the start of the Younger Dryas, but the issue of what exactly did trigger the onset of the Younger Dryas is unresolved.” In place of the comet Schoch offers a solar outburst, which he argues for at far greater length elsewhere and asserts here with more confidence than these pages support; but a writer in this territory who refuses the convenient catastrophe, and says out loud that the trigger is unknown, has paid for the right to propose his own. Our Younger Dryas ledger arrives at the same place from the proponents’ own numbers, and the impact literature has fared no better since the book: a comprehensive refutation in 2023, the Greenland platinum spike attributed to Icelandic volcanism in 2025, and two of the Comet Research Group’s papers retracted in February 2026.

So the complaints, because a signed review owes them, and because this book invites them. The dating chain has a hinge that cannot carry it: every seismic date in the book assumes that the floor behind the rump was first exposed around 2500 BCE, which is a Khafre date borrowed from the very chronology under attack, and assumes a weathering rate, which Schoch calls crude and treats as roughly linear after arguing that it is not. Chapter six hands the burden to geology; chapter seven says archaeoastronomy and myth “only go so far” and that “what is demanded by the doubters is physical evidence”; each half defers to the other, and then the epilogue, the shortest and last-written section, says “Unequivocally, the original statue, the core body of the Great Sphinx, belongs to an earlier epoch and an older civilization.” That register belongs to the epilogue alone; none of the seven chapters before it reaches for the adverb, and they are better chapters for not trying.

The book’s chief witnesses do not agree with it. Hassan, quoted more than any other Egyptologist, attributed the Sphinx to Khafre, which Schoch states plainly in chapter seven while the rest of the book quotes only his reservation. Colin Reader, presented as a corroborating geologist, dates the excavation to the early dynastic period, a few centuries before Khafre rather than seven thousand years, and Bauval’s chapter one says Reader “stayed safely within the accepted dynastic period,” as if that were a failure of nerve rather than a different conclusion from the same rock. The two Salento papers offered as independent testing of the Orion correlation found, in the book’s own words, that the theory “could not be falsified,” which is not the same as support; and the point that follows is mine rather than the book’s: the one that reached print did so in a journal of Scientific Research Publishing, a house whose peer review has been questioned in print often enough that the label should not be allowed to do the work the book asks of it.

Chapter four deserves its own complaint, and the book half makes it for me. It runs three kinds of testimony about the face as one line: the early modern travellers, from Sandys in 1615 seeing “an Aethiopian woman” to Volney, whose pages of the 1780s are an argument about the slave trade before they are an observation of a statue; the artists, Denon finding that “the character is African”; and the modern forensics, Frank Domingo’s 1993 conclusion that the face is not Chephren’s and Sheldon Peck’s letter reading prognathism into the profile, set beside a German forensic group that reached the opposite result in 1999, after which the authors offer a joke about experts being wrong rather than a reason to prefer either study. Then they add their own eye: “We, too, perceive the face of the Sphinx as African-Negroid.” The book has already said, in the same chapter, that whether the face is Khufu’s or Khafre’s “does not really make much difference” to its case, and I agree, which is why the chapter would have been better at half the length, with the travellers, the artists and the anthropometry kept apart and none of them asked to carry what the geology carries.

Nine years on, the attribution has not moved, and nothing in this paragraph or the next is in the book; it is the record since. Mainstream Egyptology still places the Sphinx in the Fourth Dynasty and argues about which king; the water-erosion reading is filed under fringe in the general references; the six surface-luminescence dates the book reprints from Liritzis and Vafiadou’s 2015 paper fall between 3100 and 1050 BCE and were published as dates for the temples’ stonework, which Schoch reinterprets as dating reworking rather than building, on the fair ground that a few minutes of sunlight resets the clock, a move that is legitimate in principle and would absorb any luminescence result whatever. One recent experiment bears on the subject from an angle neither author anticipated. In 2023 Boury, Weady and Ristroph published laboratory work in Physical Review Fluids showing that sphinx-like forms arise on their own as wind-carved yardangs, which speaks to the shape the first carvers may have started from, which chapter one and Schoch’s 1992 note on the head had already half-proposed, and which says nothing about when.

The ground has also been looked at without being cut. In March 2019 the Glen Dash Foundation, working with Lehner and Hawass, ran a ground-penetrating radar survey in front of the south-east corner of the Sphinx Temple, at the spot where runoff from a hard rain vanishes down a crevasse. The report, published in AERAGRAM in 2024 under the title “Where the Water Disappears,” found a uniform reflection about a metre down, read as quarried levelling blocks, and right-angled reflections to about four metres that the team took for a second course of buried blocks rather than a tunnel: an engineered substructure at the edge of what Lehner’s model of the site treats as a harbour. The same report records that drill cores from Hawass’s 1980 work east of the temples hit a twelve-metre drop in the bedrock with fragments of Aswan granite at the bottom, which is the buried cliff the 1991 seismic line mapped and the book reports without the earlier cores; and it closes by saying that what the radar shows can only be confirmed by direct observation. That is the state of play: everything except the measurement that would settle it. The book names the tests itself, in a 1992 paragraph that has not needed revising: seismic lines parallel to the western one, samples of the limestone, cosmogenic isotope dating of the exposed surfaces, dates on the earliest mortar, and, from chapter two, a look inside the cavity under the left paw. Every one of those is a matter of permission and money rather than of method, and the fact that a question this famous has been left to argument for thirty-five years when it could have been measured is the strangest thing in the whole affair.

Why it belongs on this site is that the station already prices half of what the book claims and is waiting on the other half. The Orion bench holds Bauval’s sky and his critics’ protractor on the same screen; the Younger Dryas ledger tests appendix nine’s rejected comet against its five requirements; the Fingerprints of the Gods note covers the version of this argument that reached the widest audience, with both these men as its sources, and the Giza Power Plant note covers the building next door. The number I most want on a bench is the one this book supplies the parts for and no one has yet built: four velocities, four depths, one ratio, and the assumptions that turn a ratio into a year, set out so that a reader can move the baseline and the rate and watch the date move with them. The book is honest enough to make that instrument possible. My verdict on it is close to Schoch’s own on his data: the case that the Sphinx is older than Khafre is stronger than the case that it is twelve thousand years old, the book knows the difference, and it says so in every chapter except the last. Read it for chapter three, for the geology of chapter seven, for the two reprinted papers, and for an appendix that turns down a comet. Hold appendix one and the Age of Leo at arm’s length. It is the best book its question has had, written by two people who expect to be checked, and the thing that would check them is still a metre under the floor of the enclosure, where they have been asking someone to go and take it since 1992.

The wiki already carries the two authors, their two hypotheses, and the sites and documents their argument runs through; the entries below are the ones this review leans on.

References and further reading

Origins of the Sphinx: Celestial Guardian of Pre-Pharaonic Civilization, Robert M. Schoch and Robert Bauval, Inner Traditions, Rochester, Vermont, 2017, the edition read here
Richard William Howard Vyse, Operations Carried On at the Pyramids of Gizeh in 1837, vol. III, London, 1842, Appendix, Samuel Birch’s note on the large tablet, p. 115, the earliest printed reading of line 13 and the sentence after it
W. M. Flinders Petrie, A History of Egypt, vol. I, London, 1894, for the granite temple “often misnamed the temple of the Sphinx”
Thomas L. Dobecki and Robert M. Schoch, “Seismic Investigations in the Vicinity of the Great Sphinx of Giza, Egypt,” Geoarchaeology 7(6), 1992, the survey behind chapter two; Robert M. Schoch, “Redating the Great Sphinx of Giza,” KMT 3(2), 1992, reprinted as appendix six
K. Lal Gauri, John J. Sinai and Jayanta K. Bandyopadhyay, “Geologic Weathering and Its Implications on the Age of the Sphinx,” Geoarchaeology 10(2), 1995; James A. Harrell, “The Sphinx Controversy: Another Look at the Geological Evidence,” KMT 5(2), 1994; Mark Lehner, KMT 5(3), 1994, the replies appendix seven answers
Colin Reader, “A Geomorphological Study of the Giza Necropolis, with Implications for the Development of the Site,” Archaeometry 43(1), 2001, and “Giza Before the Fourth Dynasty,” Journal of the Ancient Chronology Forum 9, 2002, the rainfall-runoff case and its early dynastic date
Ioannis Liritzis and Asimina Vafiadou, “Surface Luminescence Dating of Some Egyptian Monuments,” Journal of Cultural Heritage 16(2), 2015, the six dates chapter seven reinterprets
Robert Bauval, “A Master-Plan for the Three Pyramids of Giza Based on the Configuration of the Three Stars of the Belt of Orion,” Discussions in Egyptology 13, 1989; E. C. Krupp, “Pyramid Marketing Schemes,” Sky & Telescope, February 1997; Anthony Fairall, Astronomy and Geophysics 40(3), 1999
Selim Hassan, The Sphinx: Its History in the Light of Recent Excavations, Cairo, 1949, the excavator’s account both authors quote
Robert Temple with Olivia Temple, The Sphinx Mystery: The Forgotten Origins of the Sanctuary of Anubis, Inner Traditions, 2009, the moat and jackal theories appendix eight answers
Vance T. Holliday et al., “Comprehensive Refutation of the Younger Dryas Impact Hypothesis,” Earth-Science Reviews 247, 2023, where the argument of appendix nine went next
Samuel Boury, Scott Weady and Leif Ristroph, “Sculpting the Sphinx,” Physical Review Fluids 8, 2023, the yardang experiment
Rebecca D. Sperber, Dean Goodman, Mark Lehner and Glen Dash, “Where the Water Disappears: A Ground-Penetrating Radar Survey near the Great Sphinx of Giza,” AERAGRAM 25, nos. 1 and 2, 2024, pp. 19 to 23, with Zahi Hawass and Mark Lehner, “The Return to the Sphinx Viewing Project,” p. 18 of the same issue
On this site: the Precession and Orion Correlation bench and the Younger Dryas Impact Ledger, where the book’s sky and its rejected comet are priced; the source notes on Hancock’s Fingerprints of the Gods, which carried both authors’ work to its largest audience, and Dunn’s The Giza Power Plant, the building next door

Origins of the SphinxRobert SchochRobert BauvalGreat SphinxKhafreDream StelaSphinx Water ErosionOrion CorrelationPrecession of the EquinoxesGöbekli TepeYounger DryasGizaBook

Related wiki entries§

References and further reading§

Related wiki entries

References and further reading