21. HEAT AND FIRE
In the scheme of things, the ‘god / Pharaoh’ vaporised into transcendent incandescence inside the upper chamber of the Great Pyramid. If that were really so then we would logically expect to see signs of fire and heat in the remaining structure. Perhaps even a controlled ‘explosion’.
And we do. The chamber is built like a blast containment structure and it has obvious well- documented indications of suffering intense heat. 
The upper (King’s) chamber is designed and built as if for ‘blast containment’, with independent floor, wall and ceiling components to allow flexing.
The door is the minimum possible size, just sufficient to allow passage of the coffer; and it was sealed by a heavy triple portcullis (now missing).
The floor ‘floats’ independently inside the walls.
The walls are of granite which has better thermal expansion characteristics than limestone.
The ceiling is composed of five separated layers each of nine granite beams; with the spaces in between originally filled with insulation of dead black-beetle shells.
The first inter-beam space is connected by a small tunnel (Davison’s passage) leading back into the top of the Grand Gallery – like a Eustachian tube allowing pressure equalisation.
The ceiling beams are smooth and polished on the underside, to reflect heat; but irregular and rough on the upper-side to maximise re-radiation of heat.
The whole ceiling beam structure ‘floats’ under a substantial gable which is supported on limestone walls – behind the granite lining.
Vyse in 1837 and Petrie again in the late 1880s both made the mistake of assuming the multi-beam ceiling complex was intended to support what they called the ‘superincumbent weight’ of the masonry overhead. But that is not the case at all – the ceiling actually ‘floats’ under the gable which is supported on the hidden side walls. When Vyse first explored the ceiling spaces he emerged covered in black dust which was analysed as debris of black beetle shells – made of chitin which is light and inert, like an early form of fibreglass insulation.
Not only is the chamber engineered like a blast-containment structure, it also has obvious well-documented signs of having been actually used for that purpose.
The original coffer shows as normal greyish granite where a corner has been chipped by vandals, but otherwise its exterior has an unusual reddish-brown appearance as if it has been intensely baked, almost scorched.
Early explorers reported that the chamber’s granite walls were smoothly polished, almost reflective. However the meticulous Petrie noted that the stone is in fact only roughly dressed – but the walls ‘glisten’ in light because the surfaces are lightly fused, as if by extreme heat.
Petrie exactingly re-measured everything and recorded that the chamber – ‘has moved an inch or two … it is not in its original form. On every side joints have separated and the whole structure is larger.’ In plain language, it has expanded.
He also re-explored the ceiling structure and found the roof beams have moved fully 3 inches (75 mm), which he attributed to ‘subsidence’ of the supporting wall – falling into Vyse’s trap of assuming the movement was caused by weight above. But in fact, there is no suggestion that any part of the pyramid body has subsided. The roof beams have moved 75 mm relative to the walls because the beams have been lifted; the ceiling has expanded just as the chamber itself has expanded, as it was engineered to do.
In the side walls are two small openings, about 210 mm (8 in.) square, forming the inner ends of the ‘vent shafts’ which run to the outside on the upper face of the pyramid. The two inner openings, when first seen by European explorers, were blackened as if scorched and the local explanation recorded was that the vent was blackened ‘by a flame of fire which darted through it’.
The two side ‘vents’ blackened by fire are particularly interesting in as much as their existence and function is documented in the ancient texts, which record not only that a fearsome fire arose inside the pyramid:
I am he who dwells in the shining Mansion of Sunrise in Heliopolis, I am he who rises, he of the Pyramidion …
… the sky thunders, the earth quakes … [it] makes the heart leap with fright, fierce of brilliance, a flame before the wind to the end of the sky and to the end of the earth…
but also that the fire extended and was visible beyond the pyramid, specifically as two plumes:
The apertures of the sky windows are open …the flame goes forth from the horizon …
The great storm goes forth from the inner horizon. By what means will he fly up …
by two plumes…of the south wind, and the north wind.
Thou art exceedingly mighty …thou settest thy fear in all the world… the prince of light and radiance …the sacred form, beloved terrible and mighty in his two risings. 
Those clear references have interesting implications. Not only was the nuclear device pre-tested at Jebel Barkal, and very carefully ‘weighed in the balance’ to make sure it was assembled to correct specifications, but it was placed in a highly engineered blast-containment chamber … and finally the chamber was externally vented. As if the vents were a final safety valve?
In that respect, the Great Pyramid was physically different from all the others. Where the other Old Kingdom pyramids had a single, closed internal chamber at ground level – the Great Pyramid had two chambers with the main (ignition) chamber elevated to halfway up the structure, and vented to the outside.
Why did the Great Pyramid have such an unusual internal structure, with an elevated, engineered vented chamber with a reusable portcullis door? More of that later.
The structure and function of the Great Pyramid chambers and shafts is clearly consistent with the scheme of events in the ancient texts, But we still don’t know the nature of the actual nuclear device.