Joachim Friedrich Quack
Ancient Egyptian pyramids were funerary monuments. Besides the three world-famous pyramids at Giza, Egypt contains the remains of over eighty other large royal pyramids that were built during the Old and Middle Kingdoms, and of hundreds of smaller pyramids that adorned the New Kingdom tombs of private individuals; large groups of small royal pyramids were later built in Nubia, modern Sudan. Symbols of the connection between earth and sky, pyramids were built along the Nile for nearly three thousand years, displaying a range of shapes, dimensions, and construction techniques.
Our knowledge of these monuments is extensive yet uneven: a linear evolution of shape and layout appears to proceed alongside the periodic appearance of unique elements; the few extant mathematical sources from ancient Egypt provide information on how the slope of these monuments was measured and calculated, but not on how it was chosen; the precision of the orientation of the sides towards the four cardinal points indicates a stellar alignment, but the identification of the stars involved in the process is still doubtful; the archaeological evidence suggests that ramps where used in the construction, but their structure and shape can only be guessed. Therefore, the main challenge in the ongoing study of pyramids is that of combining various sources and reckoning with the simultaneous presence of recurring elements and unique circumstances.