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Great Pyramid of Giza

2007 Schools Wikipedia Selection. Related subjects: Ancient History,
Classical History and Mythology; Architecture

   Great Pyramid of Giza

   Great Pyramid of Giza was the world's tallest building from ~2570 BC to
   ~1300 AD.*
   Preceded by Red Pyramid of Sneferu, Egypt
   Surpassed by Lincoln Cathedral
   Information
   Location Giza, Egypt
   Status Complete
   Constructed ~2570 BC
   Height
   Roof 138.8 m, 455.2 ft (Formerly height: 146.6 m, 480.9 ft)
   * Fully habitable, self-supported, from main entrance to rooftop; see
   world's tallest structures for other listings.
   Great Pyramid of Giza from a 19th century stereopticon card photo.
   Enlarge
   Great Pyramid of Giza from a 19th century stereopticon card photo.

   The Great Pyramid of Giza ( 29°58′44.68″N, 31°08′02.58″E) is the only
   remaining structure of the Seven Wonders of the World along with being
   the oldest. Most Egyptologists agree the pyramid was constructed over a
   20 year period concluding around 2560 BC. It is generally believed the
   Great Pyramid was built as the tomb of Fourth dynasty Egyptian pharaoh
   Khufu (Cheops), after whom it is sometimes called Khufu's Pyramid or
   the Pyramid of Khufu. Khufu's vizier, Hemon, is credited as the
   architect of the Great Pyramid.

Historical context

   Believed by mainstream Egyptologists to have been constructed in
   approximately 20 years and 20 days, the generally accepted estimated
   date of its completion is c. 2560 BC. This date is loosely supported by
   archaeological 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 bordering what is now Cairo, Egypt in Africa. It is
   the main part of a complex setting of buildings that included two
   mortuary temples in honour of Khufu (one close to the pyramid and one
   near the Nile), three smaller pyramids for Khufu's wives, an even
   smaller "satellite" pyramid, a raised causeway connecting the two
   temples, and small mastaba tombs surrounding the pyramid for nobles.
   One of the small pyramids contains the tomb of queen Hetepheres
   (discovered in 1925), sister and wife of Sneferu and the mother of
   Khufu. There was a town for the workers of Giza, including a cemetery,
   bakeries, a beer factory and a copper smelting complex. More buildings
   and complexes are being discovered by The Giza Mapping Project.

   A few hundred meters south-west of the Great Pyramid lies the slightly
   smaller Pyramid of Khafre, one of Khufu's successors who is also
   commonly considered the builder of 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. In modern day, the pyramid of
   Khafre is the tallest of the three pyramids since the Great Pyramid has
   lost about 30 feet of material from its tip. In ancient times, Khufu's
   pyramid was indeed taller, but even then, Khafre's pyramid appeared
   taller because its sides are at a steeper angle than Khufu's pyramid
   and it was constructed on higher ground.

Construction theories

   RJ or RL-shaped supports possibly used to raise several-ton stone
   blocks.
   Enlarge
   RJ or RL-shaped supports possibly used to raise several-ton stone
   blocks.

Materials and workforce

   Many varied estimates have been made regarding the workforce needed to
   construct the Great Pyramid. Herodotus, the Greek historian in the 5th
   century BCE, estimated that construction may have required 20,000
   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 enormous additional 60,000 off-site.
   19th century Egyptologist William Flinders Petrie proposed that the
   workforce 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 100,000 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 accepted workforce
   size. For instance, mathematician Kurt Mendelssohn calculated that the
   workforce may have been 50,000 men at most, while Ludwig Borchardt and
   Louis Croon placed the number at 36,000. According to Verner, a
   workforce of no more than 30,000 was needed in the Great Pyramid's
   construction.

   A construction management study (testing) carried out by the firm
   Daniel, Mann, Johnson, & Mendenhall in association with Mark Lehner and
   other Egyptologists, estimates that the total project required an
   average workforce of 13,200 people and a peak workforce of 40,000.
   Without the use of pulleys, wheels, or iron tools, they surmise the
   Great Pyramid was completed from start to finish in approximately 10
   years. Their critical path analysis study reveals estimates that the
   number of blocks used in construction was between 2-2.8 million (an
   average of 2.4 million), but settles on a reduced finished total of 2
   million after subtracting the estimated area of the hollow spaces of
   the chambers and galleries. Most sources agree on this number of blocks
   somewhere above 2 million. The Egyptologists' calculations suggest the
   workforce could have sustained a rate of 180 blocks per hour (3
   stones/minute) with ten hour work days for putting each individual
   block in place. They derived these estimates from construction projects
   that did not use modern machinery. This study fails to take into
   account however, especially when compared to modern third world
   construction projects, the logistics and craftsmanship time inherent in
   constructing a building of nearly unparalleled magnitude with such
   precision, or among other things, the use of up to 60-80 ton stones
   being quarried and transported a distance of over 500 miles.
   Some blocks weigh up to 60-80 tons
   Enlarge
   Some blocks weigh up to 60-80 tons

   In contrast, a Great Pyramid feasibility study relating to the
   quarrying of the stone was performed in 1978 by Technical Director
   Merle Booker of the Indiana Limestone Institute of America. Consisting
   of 33 quarries, the Institute is considered by many architects to be
   one of the world’s leading authorities on limestone. Using modern
   equipment, the study concludes:

          “Utilizing the entire Indiana Limestone industry’s facilities as
          they now stand [for 33 quarries], and figuring on tripling
          present average production, it would take approximately 27 years
          to quarry, fabricate and ship the total requirements.”

   Booker points out the time study assumes sufficient quantities of
   railroad cars would be available without delay or downtime during this
   27 year period and does not factor in the increasing costs of
   completing the work.

   The entire Giza Plateau is believed to have been constructed over the
   reign of five pharaohs in less than a hundred years. Beginning with
   Djoser who ruled from 2687-2667 BCE, 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. Also during this
   period (between 2686 and 2498 BCE) the Wadi Al-Garawi dam which used an
   estimated 100,000 cubic meters of rock and rubble was built.

   The accepted values by Egyptologists bear out the following result:
   2,400,000 stones used ÷ 20 years ÷ 365 days per year ÷ 10 work hours
   per day ÷ 60 minutes per hour = 0.55 stones laid per minute.

   Thus no matter how many workers were used or in what configuration, 1.1
   blocks on average would have to be put in place every 2 minutes, ten
   hours a day, 365 days a year for twenty years to complete the Great
   Pyramid within this time frame. This equation, however, does not take
   into account designing, planing, surveying, and leveling the 13 acre
   site the Great Pyramid sits on.

Layout

   Map of Giza pyramid complex.
   Enlarge
   Map of Giza pyramid complex.

   Papyrus documents and existing cubit measuring rods give us the units
   of measure used to specify the plan of the pyramid and so it is thought
   that, at construction, the Great Pyramid was 280 Egyptian Old Royal
   Cubits tall (146.6 meters or 480.9 feet), but with erosion and the
   theft of its topmost stone (the pyramidion) its current height is 455.2
   feet approximately 138.8 m and that each base side was 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 51.50.40 degrees (
   seked = 5½)—close to the ideal for a stable pyramidal structure. Today
   each side has an approximate length of about 230.4 meters(755.8 feet).
   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 metres thick
   and weighed more than 15 tonnes.

   In the 14th century (1301 CE), a massive earthquake loosened many of
   the outer casing stones, which were then 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 ft 16 in ± 10"). Petrie suggested a
   redetermination of north was made after the construction 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 BCE.

   For four millennia it was the world's tallest building, unsurpassed
   until the 160 metre tall spire of Lincoln Cathedral was completed c.
   1300 CE. The accuracy of the pyramid's workmanship is such that the
   four sides of the base have a mean error of only 58 mm in length, and 1
   minute in angle from a perfect square. The base is horizontal and flat
   to within 15 mm. The sides of the square are closely aligned to the
   four cardinal compass points to within 3 minutes of arc and is based
   not on magnetic north, but true north. The ratio of the pyramid's
   perimeter to two times its height is approximately 3.1421, about 0.1%
   off from the mathematical constant pi.

   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. It 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,
   making it visible from a considerable distance. 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
   true plane over their entire surface area by only 1/50th of an inch.
   They were fitted together so perfectly that the tip of a knife cannot
   be inserted between the joints even to this day.

   The passages inside the pyramid are all extremely straight and precise,
   such that the longest of them, referred to as the descending passage,
   which is 350' 0.25" long deviates from being truly straight by less
   then 0.25 inches, while one of the shorter passages with a length of
   just over 150 feet deviates from being truly straight by a mere 0.020
   inches. These and the above statistics prove the pyramid to be
   literally the most accurately constructed building on the face of the
   earth despite having been created several millennia ago. All theories
   which sufficiently allow for this level of accuracy assume a level of
   technology approximately equal to or exceeding current technology, at
   least in the area of toolmaking and construction.

   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
   appear however to 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 known 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 towards
   the outer surface of the pyramid. These shafts were explored using a
   robot, Upuaut 2, created by Rudolf Gantenbrink. Upuat 2 discovered that
   these shafts were blocked by limestone "doors". During Pyramids Live:
   Secret Chambers Revealed, National Geographic filmed the drilling of a
   small hole in the southern door only to find another larger door behind
   it. The northern passage (which was harder to navigate due to twists
   and turns) was also found to have a door. 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.

   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 halloed
   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 centre length at floor level. What purpose these sockets served is
   unknown. The Red Pyramid of Dashur also exhibits grand galleries of
   similar design.

   The sarcophagus of the King's chamber was hollowed out of a single
   piece of Red Aswan granite and has been found to be too large to fit
   through the passageway leading to the King's chamber. Whether the
   sarcophagus was ever intended to house a body is unknown, but it is too
   short to accommodate a medium height individual without the bending of
   the knees (a technique not practised in Egyptian burial) and no lid was
   ever found.

   The "unfinished chamber" lies 90 ft below ground level and is
   rough-hewn, lacking the 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. Given the extreme precision and planning given to
   every other phase of the Great Pyramid's construction, this conclusion
   seems surprising.

   Two French amateur Egyptologists, Gilles Dormion and Jean-Yves
   Verd'hurt, claimed in August 2004 that they had discovered a previously
   unknown chamber inside the pyramid underneath the Queen's Chamber using
   ground-penetrating radar and architectural analysis. They believe the
   chamber to be unviolated and could contain the king's remains. They
   believe the King's Chamber, the chamber generally assumed to be Khufu's
   original resting place, was not constructed to be a burial chamber.

Dating evidence

   The Edgar Cayce Foundation, researching claims that the pyramids were
   at least 10,000 years old, funded the "David H. Koch Pyramids
   Radiocarbon Project" in 1984. The project took samples of organic
   material (such as ash and charcoal deposits) from several locations
   within the Great Pyramid, and other pyramids and monuments from the Old
   Kingdom period (ca. 3rd millennium BC). These samples were subjected to
   radiocarbon dating to produce calibrated date-equivalent estimates of
   their age. This yielded results averaging 374 years earlier than the
   estimated historical date accepted by Egyptologists (2589 — 2504 BC)
   but still more recent than 10,000 years ago. An astronomical study by
   Kate Spence suggests the pyramid dates to 2467 BC.

   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 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 theorized 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, given the poor quality and relative scarcity
   of native Egyptian woods, that King Sneferu (and later Egyptian
   pharohs) imported fine woods from Lebanon and other countries such as
   Nubia for the creation of decorative furniture, royal boats (as found
   buried around the Giza Plateau), or other luxuries generally reserved
   for royalty. Mark Lehner points out that this was not without "great
   cost". It is unknown, given the expense, effort, and value of such
   woods, if they were ever imported as an expendable source of industrial
   fuel, especially on such a large scale.

   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 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. As
   of yet the full data of the study has yet to be released in which the
   authors insist more evidence is needed to settle this issue. In the
   absence of the "old wood" theory, the study admits "The 1984 results
   left us with too little data to conclude that the historical chronology
   of the Old Kingdom was in error by nearly 400 years, but we considered
   this at least a possibility."

   In his book Voyages of the Pyramid Builders , Boston University geology
   professor Robert Schoch details key anomalies in both radiocarbon
   studies; most notably that samples taken in 1984 from the upper courses
   of the Great Pyramid gave upper dates of 3809 B.C. (± 160yrs), nearly
   1400yrs before the time of Khufu, while the lower courses provided
   dates ranging from 3090-2723 B.C (± 100-400yrs) which correspond much
   more closely to the time Khufu is believed to have reigned. Given that
   the data imply the pyramid was built (impossibly) from the top down,
   Dr. Schoch argues that if the information provided by the study is
   correct, it makes sense if it is assumed the pyramid was built and
   rebuilt in several stages suggesting later Pharaohs such as Khufu were
   only inheritors of an existing monument, not the original builders, and
   merely rebuilt or repaired previously constructed sections.

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