Argentinean Dr. E. Gull (collaborator in the construction of the mirror of 5 meters of Hard-twisted Mount) there would be an equivalence, as feat of optic engineering, among the one carved of the mirror and the production of the blocks of the pyramidal lining, with seven plane surfaces of three squared meters each one. But some scientists sustain that a prism is a figure extremely difficult of carving, mainly in those dimensions, because to achieve the required precision they should keep in mind, with object of compensating them, the deformations taken place by the weight of the masses.

 For these, the feat of the great pyramid was, qualitative and quantitatively superior to ours. And the only thing that we have left of that civilization is some remains that give faith of their great technical knowledge and their scientific vocation. The study of this lining began with the eminent archaeologist Sir W. M. Fliders Petrie. According to Petrie the precision of the one carved of the marble it was such that he had to take an arsenal of instruments of precision to Egypt. But the precision was such that the instruments were on gone by the grade of precision in carved him of the marble and other elements coming from the but remote antiquity. Thirty years later you organizes a second scientific expedition in charge of the German Department of Archaeology, endowed with an instrumental of more precision that again you is overflowed by the accuracy of the size. Alone now we are under conditions of carrying out measures with the required precision, using the modern technique of the “Máser” that has not still been used for these ends in Egypt. The lining was during a lot of time, but toward the 1250 d.c., with the arrival of the Ottoman to Egypt, it began the pillaging and destruction. If now we can speak of this lining it is because toward the north side of the Great Pyramid they accumulated big dunes that protected the lining of the pillaging. This lining that is this compound for forty marbles that constitute a wall of about 10 meters high for 30 of long.

 At six in the afternoon of the day of the equinox, the north face of the Great Pyramid leaves for the half. This phenomenon has been studied by Pochan and pictures have been taken out in the days of equinox in which the graze  sun projects a shade has more than enough seemingly half of the north face that is this way departure, in two triangles: one illuminated by the sun and the other one, in the shade. This phenomenon is because the faces of the pyramid are not built by an only plane, but for planes curved on the vertical one. For it the perimeter of the base has the configuration of a cross of Malt and not that of a simple square. The precision with which it was curved the north face and the perfect astronomical adjustment of this bend they have given place to scientific works that seek to obtain dates on the Great Pyramid. In these works one highlights carried out by the commission of Atomic Energy of Brazil and carried out by a team presided over by the professor Arysio Núñez Santos. To the conclusion that you/they arrived it is that the Great Pyramid was installed approximately fourteen thousand years ago in the plateau of Gizeh.  

The pyramids of Giza. - they were built during the period of the Old Empire, for the Dynasty (2.613 at 2.498 to. C.). The reason in the triangular way of these constructions is not known, although it could be a way to reproduce the form of the Pharaohs of the IV mountains, where, for the old ones Egyptian, they inhabited the gods, or they could also understand each other as stairways for those that the spirit of the Pharaoh would arrive until the sky. They are income  in a rocky area, above the own quarry of which the limestone blocks were extracted, of smaller quality, employees for the nucleus of the pyramids. The lining of white limestone comes from the quarries of Tura; overcoming the Nile toward the South and the granite used in the construction of the passageways and the funeral cameras comes from Asuán, to 800 kilometers. The pyramids are located in the western margin of the river Nile and all were communicated with the river by means of high roads of stone, built to facilitate the transport of the stones that they arrived of the quarry.it has checked that with the blocks used for the construction of the three pyramids of Giza one could make a wall of three meters of high for 30 bulk cm that would give the turn to France. In the bigger than all, the Great Pyramid of Keops, 2.300.000 blocks of calcareous stone were used, of a weight that he goes from two tons to fifteen. He has a width 230 meters in each one of their four faces and their height is of 146 meters. The pyramid of Kefrén, son of Keops, is a little smaller: 215 meters wide for 143 of high, and that of Micerinos, grandson of Keops, is the minor: 103 Wide meters  for 66 meters high.

               

    The pyramid of Keops is the monument of more stone that has been built. Inside the pyramid they would fit five cathedrals: that of Florence, that of Milan, that of San Pedro (Rome) and the London of San Pablo and Westminster. Probably before the construction of the pyramids tests were made to scale, since they have been scale models in stone. The first phase of the works consisted on planing the land. Something that gets the attention powerfully in the geometric precision that allowed the perfect alignment of the blocks in the vertex (something that didn't happen with the pyramid of Sneferu, eats we have already seen). Each side measures 230 meters long and perfectamen is guided .It is believed that to build the pyramid of Keops they used 20 years to prepare the blocks and 10 years to place them. They only worked during the time of the grown ones of the Nile, since one could not assist the field in those periods. There are different theories on who and in how long they built the pyramids. According to the historian Herodoto (that Egypt visited in the century V to. C.) in the construction of the Great Pyramid 100.000 people worked in days of 3 months to the year, but the most recent theories it sustains that they were 4.000 people.
The blocks of the pyramids fit to each other with great precision. This makes suppose that the refined of the blocks was carried out after their placement. The quarries were near the river, so the transport was made in rafts through the Nile. The transfer until the pyramid was made through a high road of stone, road that later was used in the funeral processions. The lines of blocks seem to be that they were placed of inside toward out. To lift the blocks, the most probable thing is that a system of ramps was used and that the stones crawled for them by means of skates. It is possible also that scaffolds were used to place the calcareous lining. Of this lining it is only perseverance in the high part of the pyramid of Kefrén. It is believed that the refined of the lining was made from the vertex until the base. That that yes it seems sure it is that in the constructions of these pyramids iron tools were not used, motors neither wheels.

 Almost five thousand years later, the funeral complex of Giza, with the enigmatic sphinx built in a mountain of calcareous stone of 5 x 4 meters, presiding over it (it is supposed that it represents the Pharaoh Kefrén, although it is only a theory) it continues being witness of the Humanity's history. Every time is realler the statement that "The man fears at the time, but the time fears to the pyramids."