Great Pyramid of Giza
The Great Pyramid of Giza (29°58′41″N, 31°07′53″E) is the oldest and last remaining of the Seven Wonders of the World. It is generally believed the Great Pyramid was built as the tomb of Fourth dynasty Egyptian king Khufu (also known under his Greek name Cheops and believed to have reigned from 2606-2583 BC), after whom it is sometimes called Khufu's Pyramid or the Pyramid of Khufu. Traditionally, the architect of the pyramid was Hemon, a relative of Khufu[ citation needed].
Age and location
Believed by mainstream egyptologists to have been constructed in approximately 20 years, the most widely accepted estimate for its date of completion is c. 2580 BC. This date is loosely supported by archæological findings which have yet to reveal a civilization (of sufficient population size or technical ability) older than the fourth dynasty in the area.
The Great Pyramid is the oldest and largest of the three pyramids in the Giza Necropolis adjacent to the outskirts of modern Cairo, Egypt in Africa. It is the main part of a complex setting of buildings that included a special walkway, two temples, three small pyramids (called the queens' pyramids), boat pits (with boats buried inside) and the mastabas for the nobles. One of this small pyramids contains the tomb of queen Hetepheres (discovered in 1925),sister and wife of Sneferu and the mother of Khufu.
Also there was a town for the workers along with their cemetery, bakeries, a beer factory and a copper smelting complex. More buildings and complexes are being discovered by the The Giza Mapping Project.
A few hundred metres south-west of the Great Pyramid lie the slightly smaller Pyramid of Khafre, one of Khufu's successors who is believed to have built the Great Sphinx, and a few hundred metres further south-west is the Pyramid of Menkaure, Khafre's successor, which is about half as tall. Khafre's pyramid appears the tallest on some photographs as it is somewhat steeper and built on higher terrain.
Dating evidence
An astronomical study, by Kate Spence (see below), suggests a date of 2467 BC. (Nature (vol 408, p 320))
In 1984, the Edgar Cayce Foundation, endeavoring to research the claim that the pyramids were at least 10,000 years old, funded the "David H. Koch Pyramids Radiocarbon Project". The project took organic material from several places in the core of the Great Pyramid as well as other 4th Dynasty pyramids and locations so as to try and date their radiocarbon. This yielded results averaging 374 years earlier than the date accepted by egyptologists but much more recent than 10,000 years ago. A second dating in 1995 with new but similar material obtained dates ranging between 100-400 years earlier than those indicated by the historic record. This raised interesting questions concerning the origin and date of the wood. Massive quantities of wood were used and burned, so to reconcile the earlier dates the authors of the study theorize that possibly "old wood" was used, assuming that wood was harvested from any source available, including old construction material from all over Egypt. It is also known that King Sneferu imported wood from Lebanon. Project scientists based their conclusions on the evidence that some of the material in the 3rd Dynasty pyramid of Pharaoh Djoser and other monuments had been recycled, concluding that the construction of the pyramids marked a a major depletion of Egypt's exploitable wood. Dating of more short-lived material around the pyramid (cloth, small fires, etc) yielded dates nearer to those indicated by historical records. The authors insist more evidence is need to settle this issue. (Archeology " Dating the Pyramids " Volume 52 Number 5, September/October 1999 by members of the David H. Koch Pyramids Radiocarbon Project")
This study does not sufficiently address key anomalies in its findings, however - mainly how and where the Egyptians were able to obtain literally tons of 100-400 year old dead wood. Even preserved in a desert climate, finding forests of such magnitude comprised of ancient dead wood would be a phenomenon in and of itself. It is believed Egypt's climate would have only been able to support such a forest (though there is no evidence of one having existed at the time being largely grasslands) at the latest only prior to 4,000-6,000 BC. For this to be true an entire revision of Egypt's climatic history would be required. When considering the data, what is shown is the radio carbon of the pyramids yielded dates ranging from 100-400 years earlier than the "historical record", yet the signs of last casual occupation, ie. cloth, small fires, etc, have given dates much closer to what is expected from egyptologists. Instead of requiring a revision of Egypt's climatic history based solely on the fact these dates do not support accepted theory despite supporting climatology data to the contrary, it is equally possible that what the study suggests is true--that the pyramids are indeed older (if only by 100-400 years) than what is currently believed.
Construction and internal layout
At construction, the Great Pyramid was 280 Egyptian Old Royal Cubits tall ( 146.5 metres or 481 feet), but with erosion and the theft of its topmost stone (the so-called pyramidion) its current height is 455.21 ft, approximately 138.75 m. As has been proven by papyrus documents, each base side measured in antiquity 440 (20.63 inch) royal cubits. Thus, the base was originally 231 m on a side and covered approximately 53,000 square metres with an angle of 51.7 degrees—close to the ideal for a stable pyramidal structure. Today each side has an approximate length of about 230.36 meters, well within the precision of that measurement. The reduction in size and area of the structure into its current rough-hewn appearance is due to the absence of its original polished casing stones, some of which measured up to two and a half meters thick and weighed upwards of 15 tonnes.
In the 14th century (1301 AD), a massive earthquake loosened many of the outer casing stones, many of which were carted away by Bahri Sultan An-Nasir Nasir-ad-Din al-Hasan in 1356 in order to build mosques and fortresses in nearby Cairo; the stones can still be seen as parts of these structures to this day. Later explorers reported massive piles of rubble at the base of the pyramids left over from the continuing collapse of the casing stones which were subsequently cleared away during continuing excavations of the site. Nevertheless, many of the casing stones around the base of the Great Pyramid can be seen to this day in situ displaying the same workmanship and precision as has been reported for centuries.
The first precision measurements of the pyramid were done by Sir Flinders Petrie in 1880–82 and published as " The Pyramids and Temples of Gizeh". Almost all reports are based on his measurements. Petrie found the pyramid is oriented 4' West of North and the second pyramid is similarly oriented. Petrie also found a different orientation in the core and in the casing ( – 5' 16" ± 10"). Petrie suggested a redetermination of North was made after the contruction of the core, but a mistake was made, and the casing was built with a different orientation. This deviation from the north in the core, corresponding to the position of the stars b-Ursae Minoris and z-Ursae Majoris about 3,000 years ago, takes into account the precession of the axis of the Earth. A study by egyptologist Kate Spence , shows how the changes in orientation of 8 pyramids corresponds with changes of position of those stars through time. This would date the start of the construction of the pyramid at 2467 BC.
For four millennia it was the world's tallest building, unsurpassed until the 160 metre tall spire of Lincoln Cathedral was completed c. 1300 AD. The accuracy of the pyramid's workmanship is such that the four sides of the base have a mean error of only 50 mm in length, and 12 seconds in angle from a perfect square. The sides of the square are closely aligned to the four ordinal compass points to within 3 minutes of arc and is based not on magnetic north, but true north.
The pyramid was constructed of cut and dressed blocks of limestone, basalt or granite. The core was made mainly of rough blocks of low quality limestone taken from a quarry at the south of Khufu’s Great Pyramid. These blocks weighed from two to four tonnes on average, with the heaviest used at the base of the pyramid. An estimated 2.4 million blocks were used in the construction. High quality limestone was used for the outer casing, with some of the blocks weighing up to 15 tonnes. This limestone came from Tura, about 8 miles away on the other side of the Nile. Granite quarried nearly 500 miles away in Aswan with blocks weighing as much as 60-80 tonnes, was used for the portcullis doors and relieving chambers.
The total mass of the pyramid is estimated at 5.9 million tonnes with a volume (including an internal hillock) believed to be 2,600,000 cubic metres. The pyramid is the largest in Egypt and the tallest in the world and is surpassed only by the Great Pyramid of Cholula in Puebla, Mexico, which, although much lower in height, occupies a greater volume.
At completion, the Great Pyramid was surfaced by white 'casing stones' – slant-faced, but flat-topped, blocks of highly polished white limestone. These caused the monument to shine brightly in the sun and even in the evening under moonlight being visible from mountains in the south of Egypt as far away as 200 miles (300 km). Visibly all that remains is the underlying step-pyramid core structure seen today, but several of the casing stones can still be found around the base. The casing stones of the Great Pyramid and Khafre's Pyramid (constructed directly beside it) were cut to such optical precision as to be off of true plane over their entire surface area by only as little as 1/50th of an inch. They were fit together so perfectly that the tip of a knife cannot be inserted between the joints along any edge even to this day.
The Great Pyramid differs in its internal arrangement from the other pyramids in the area. The greater number of passages and chambers, the high finish of parts of the work, and the accuracy of construction all distinguish it. The walls throughout the pyramid are totally bare and uninscribed, but there are inscriptions — or to be more precise, graffiti — believed to have been made by the workers on the stones before they were assembled. All the five relieving chambers are inscribed. The most famous inscription is one of the few that mentions the name of Khufu; it says "year 17 of Khufu's reign". Although alternative theorists have suggested otherwise, given its precarious location it is hard to believe it could have been inscribed after construction; even Graham Hancock accepted this, after Dr Hawass let him examine the inscription. Another inscription refers to "the friends of Khufu", and probably was the name of one of the gangs of workers. Though this doesn't offer indisputable proof Khufu originated the construction of the Great Pyramid or when building began, it does however clear any doubt he at least took part in some phase of its construction (or later repairs to an existing building) during his reign.
There are three chambers inside the Great Pyramid. These are arranged centrally, on the vertical axis of the pyramid. The lowest chamber (the "unfinished chamber") is cut into the bedrock upon which the pyramid was built. This chamber is the largest of the three, but totally unfinished, only rough-cut into the rock.
The middle chamber, or Queen's Chamber, is the smallest, measuring approximately 5.74 by 5.23 metres, and 4.57 metres in height. Its eastern wall has a large angular doorway or niche, and two narrow shafts, about 20 centimeters wide, extending from the chamber to the outer surface of the pyramid, but blocked by limestone "doors" at several points. Egyptologist Mark Lehner believes that the Queen's chamber was intended as a serdab—a structure found in several other Egyptian pyramids—and that the niche would have contained a statue of the interred. The Ancient Egyptians believed that the statue would serve as a "back up" vessel for the Ka of the Pharaoh, should the original mummified body be destroyed. The true purpose of the chamber, however; remains a mystery. [1]
At the end of the lengthy series of entrance ways leading into the pyramid interior is the structure's main chamber, the King's Chamber. This chamber was originally 10 x 20 x 5V5 cubits, or about 17 x 34 x 19 ft, roughly a double cube.
The other main features of the Great Pyramid consist of the Grand Gallery, the sarcophagus found in the King's Chamber, both ascending and descending passages, and the lowest part of the structure mentioned above, what is dubbed the "unfinished chamber".
The Grand Gallery (49 x 3 x 11 m) features an ingenious corbel halled design and several cut "sockets" spaced at regular intervals along the length of each side of its raised base with a "trench" running along its center length at floor level. What purpose these sockets served is unknown. The Red Pyramid of Dashur also exhibits grand galleries of similiar design.
The sarcophagus of the King's chamber was hollowed out of a single peice of Red Aswan granite and has been found to be too large to have fit through the passageway leading to the King's chamber. Whether the purpose of the sarcophagus was ever intended to house a body is unknown, but regardless, it is too short to accommodate a medium height individual without the bending of the knees (a technique unpracticed in Egyptian burial)and no lid was ever found.
The "unfinished chamber" lies 90ft below ground level and is rough-hewn, lacking the signature precision of the other chambers. This chamber is dismissed by Egyptologists as being nothing more than a simple change in plans in that it was intended to be the original burial chamber but later King Khufu changed his mind wanting it to be higher up in the pyramid. [2]. Given the extreme precision and planning given to every other phase of the Great Pyramid's contruction, this conclusion seems premature at best considering according to these same Egyptologists the whole purpose of building the structure in the first place as they claim was to house the king's burial chamber.
In August 2004 two French amateur Egyptologists, Gilles Dormion and Jean-Yves Verd'hurt, claimed that they had discovered, using ground-penetrating radar and architectural analysis, a previously unknown corridor inside the pyramid. If their claim is true, the corridor is unlikely ever to have been violated and could possibly lead to a chamber containing the king's remains. But, as yet, the pair have been refused permission by the Egyptian Supreme Council of Antiquities to follow up their findings and, they hope, prove the room's existence [ citation needed].
Labor and construction theories
Many varied estimates have been made regarding the labor force needed to construct the Great Pyramid. Herodotus, the Greek historian in the 5th century BC, estimated that construction may have required the labor of 100,000 workers for 20 years. Recent evidence has been found that suggests the workforce was in fact paid, which would require accounting and bureaucratic skills of a high order. Polish architect Wieslaw Kozinski believed that it took as many as 25 men to transport a 1.5-ton stone block; based on this, he estimated the workforce to be 300,000 men on the construction site, with an additional 60,000 off-site. 19th century Egyptologist William Flinders Petrie proposed that the labor force was largely composed not of slaves but of the rural Egyptian population, working during periods when the Nile river was flooded and agricultural activity suspended. Egyptologist Miroslav Verner posited that the labor was organized into a hierarchy, consisting of two gangs of 1000 men, divided into five zaa or phyle of 200 men each, which may have been further divided according to the skills of the workers.
Some research suggests alternate estimates to the aforementioned labor size. For instance, mathematician Kurt Mendelssohn calculated that the labor force may have been 50,000 men at most, while Ludwig Borchardt and Louis Croon placed the number at 36,000. According to Verner, a labor force of no more than 30,000 was needed in the Great Pyramid's construction.
A construction management study carried out by the firm Daniel, Mann, Johnson, & Mendenhall in association with Mark Lehner and other egyptologists (Civil Engineering magazine, June 1999), estimates that the total project required an average workforce of 13,200 people and a peak workforce of 40,000 and was completed from start to finish in approximately 10 years. The study estimates the number of blocks used in construction was between 2-2.8 million (an average of 2.4 million), but settles on a much reduced finished total of 2 million subtracting the estimated area of the hollow spaces of the chambers and galleries. Their calculations suggest the workforce could have sustained a rate of 180 blocks per hour (3 blocks every 60 seconds)with ten hour work days for putting each individual block in place. They derived these estimates from contruction projects in the third world that did not use modern machinery. This study fails to take into account however, especially when compared to modern third world construction projects, the added labor and logistics required among other things to perform the work with such precision, the entire project as a whole, or the use of up to 80 tonne stones being quarried and transported a distance of over 500 miles.
Regardless of how many workers were required for construction, to use the following equation: 2,400,000 (total stones used in construction) ÷ 20 years (estimated time of completion) ÷ 365 days in a year ÷ 10 work hours in a day ÷ 60 minutes in one hour, the resulting answer is 0.55 stones/minute. What this means is that no matter how many workers were used or in what configuration, to complete the construction of the Great Pyramid within this time frame 1.1 blocks would have to be put in place every 2 minutes, ten hours a day, 365 days a year for twenty years. To use the same equation, but instead assuming the time of completion to be one hundred years instead of twenty, it would require 1.1 blocks to be set every ten minutes, ten hours a day, 365 days a year.
These equations, however, do not include the time and labor required to design, plan, survey, and level the 13 acre site which the Great Pyramid sits on. Nor do they include construction time for the two other main pyramids on the site, the Sphinx, the temples (which feature stones weighing upwards of 200 tonnes), networks of causeways, several square miles of paving stones (which originally covered the entire Giza plateau), the leveling of the entire Giza plateau, the 35 boat pits carved out of solid bedrock (some of which are nearly 150 ft long and 30 ft deep), or several other highly laborious features.
When considering the time it would have taken to build the Great Pyramid alone, it is worth noting that the construction of the entire Giza plateau is believed to have been accomplished by three pharaohs (possibly 4 if Djedefre, Kheops' son, is considered) in less than a hundred years starting with Khufu who reigned from 2606-2583 BC and ending with Menkaure 2548-2530 BC (76 years). To apply the Great Pyramid labor formula (which only provides for the physical act of dropping the stones in place) to the entire Giza plateau would require stones, even the 80-200 tonne variety some of which were quarried over 500 miles away in Aswan, to be placed ten hours a day, 365 days a year for approximately 76 years - not every few minutes, but every few seconds. This feat becomes even more impessive given beginning with king Snefru who ruled from 2630-2606 BC (leaving a span of 100 years between the beginning of his reign and the end of Menkaure's in 2530 BC), three other massive pyramids were built: the Step Pyramid of Saqqara (believed to be the first Egyptian pyramid), the Bent Pyramid, and the Red Pyramid of Dashur. Also during this time period (between 2686 and 2498 BC), an equally impressive construction project was carried out, the Wadi Al-Garawi dam believed by some to be the world's oldest, which used an estimated 100,000 cubic metres of rock and rubble for its construction. [3]
Herodotus speculated that the stone blocks used in the Great Pyramid's construction were maneuvered into place by raising them up a succession of short wooden scaffolds. Another possibility proposed by the ancient scholar Diodorus Siculus was that the giant blocks were dragged along a system of ramps to the necessary height. More recently, Mark Lehner speculated that a spiralling ramp, beginning in the stone quarry to the southeast and continuing around the exterior of the pyramid, may have been used. In Lehner's model, the stone blocks may have been drawn on sleds lubricated by water. Another source claims milk was a lubricant.
The most precisely cut stone blocks were reserved for the outside. Once in place their corners were smoothed to give an almost shiny outer appearance of the pyramid. For the inner core, the blocks were cut with less precision, since there are gaps big enough to introduce an arm. These gaps were filled with rubble, mixed with gypsum. Recent studies by Gilles Dormion and Jean Patrice Goidin suggest the existence of cavities filled with sand, that could amount to 10 to 15% of the volume of the pyramid. This could reduce the amount of work required of the construction.
The idea of using rollers to move stone blocks was made popular in Hollywood movies, but as of today, whether it be ramp, roller, or otherwise, there are few historical records to demonstrate how ground transportation was done.
If a ramp were used to push the top-most blocks of the pyramid into place, the incline would contain more material than the pyramid itself and this material would have had to be removed after construction was completed. Excavation on the area south of the Great Pyramid revealed evidence of the remains of a ramp consisting of two walls built of stone rubble and mixed with Tafla. The area in between was filled with sand and gypsum forming the bulk of the ramp. They were discovered during the work of relocating the Sound and Light Show cables at Giza (Hawass, The Pyramids of Ancient Egypt). Given the mass required to build a ramp of such magnitude to contruct the Great Pyramid as ramp theories suggest, it is unknown what purpose this much smaller newly discovered ramp may have served.
It has also been suggested that Egyptians might have moved the stones with wind power, relying on kites and pulleys rather than huge numbers of slaves. On June 23, 2001, Caltech aeronautics professor Mory Gharib and a small team of undergraduates raised a 3000 kg, 3 metre tall obelisk into vertical position in 22 mph (35 km/h) winds in a California desert in under 25 seconds, using a 10 m kite connected to a pulley system and support frame, to demonstrate that wind power can be harnessed to create large lifting forces. The originator of this idea, business consultant Maureen Clemmons, recalled seeing a building frieze now displayed in a Cairo museum, showing a wing pattern in bas relief that did not resemble any living bird, directly below which were several men standing near vertical objects that could be ropes. However, though the engineering may have been feasible, Egyptian experts point out there is no evidence that ancient Egyptians used either kites or pulleys as we know them today.
Materials scientist Joseph Davidovits has posited that the blocks of the pyramid are not carved stone, but mostly a form of limestone concrete: i.e. they were 'cast' as with modern cement. Because of the blocks huge (2.5 to 15 tons) size each was molded in situ. [4] According to this theory soft limestone with a high kaolinite content was quarried in the wadi on the south if the Giza plateau. It was then dissolved in large, Nile-fed pools until it became a watery slurry. Lime (found in the ash of cooking fires) and natron (also used by the Egyptians in mummification) was mixed in. The pools were then left to evaporate, leaving behind a moist, clay-like mixture. This wet "concrete" would be carried to the construction site where it would be packed into reusable wooden molds. In the next few days the mixture would undergo a chemical hydration reaction similar to the 'setting' of cement. No large gangs would be needed to haul blocks, and no chiseling or carving would be required to dress their surfaces. New blocks could be cast in place, on top of and pressed against the old blocks. This would account for the unerring precision of the joints of the casing (the blocks of the core show tools marks and were cut with much lower tolerances). Proof-of-concept tests using similar compounds were carried out at a geopolymer institute in northern France. It was found that a crew of ten, working with simple hand tools, could build a structure of fourteen, 1.3 to 4.5 ton blocks in a couple of days. [5] According to Davidovits the architects possessed at least two concrete formulas: one for the large structural blocks and another for the white casing stones. He argues earlier pyramids were built using similar techniques.