The Pyramids are connected to certain scientific and astronomical phenomena

The argument

Proponents of the ancient aliens theory argue that the pyramids at Giza carry features which are difficult to attribute to coincidence, and that taken together these amount to clues about where the knowledge behind the structures came from. The first is orientation. The pyramids are aligned to true north to within a tenth of a degree. Proponents present this as an incredible feat for ancient people, and as the kind of precision that suggests a source of knowledge beyond the period. The second is a numerical coincidence. The pyramids stand at a latitude of 29.9792458°N. The speed of light is 299,792,458 metres per second. Proponents argue that the matching sequence of digits may not be a coincidence at all but a deliberate hint — a constant of physics encoded in the position of the monuments. The third concerns the sky. The three pyramids are said to line up with the stars of Orion's Belt, and the Sphinx with the constellation Leo. On this reading the arrangement is a signature rather than a decoration: the builders, or those who guided them, were indicating where they came from. None of these features is presented as proof, and the language used by proponents is consistently conditional — the alignments may be clues to an intergalactic origin, the latitude may be a hint, the aliens may have been indicating Orion. The claim is that aliens could have left humans markers pointing to the source of the knowledge used in the pyramids' construction, and that these scientific and astronomical connections are those markers.

Premises

Counter-arguments

The speed of light number is probably a coincidence. Although it does pass through the pyramid, it also passes through many other monuments. This line passes slightly North of where it is supposed to according to ufologists, it is not the apex of the pyramid. If you insist on including seven decimal places for a degree of latitude, it is possible to draw 20,000 other lines through the pyramid, none of which are interesting numbers. It is very easy to make a line of stars line up with a line on earth, everything lines up with some stars somewhere It is not very difficult to find true north by looking at the night sky and finding the pole star. We know that the Egyptians were highly skilled at astronomy and mathematics from examining ancient texts. The ancient Egyptian interest in astronomy does not imply they must have met aliens. The speed of light number is a coincidence, and not an impressive one. We know from written evidence that the Egyptians were knowledgeable about mathematics and astronomy. The is no evidence for the existence of ancient aliens, they are not a plausible alternative explanation.

Rejecting the premises

[Rejecting P1] Alignment to true north is a demonstrated human capability rather than an anomaly: the celestial pole can be located by observing the circumpolar stars, and Egyptian astronomical and mathematical competence is documented in surviving texts. That a feat is impressive is not evidence of an outside source. [Rejecting P2] The latitude coincidence dissolves on inspection. The match requires seven decimal places — a band far narrower than the monument itself, and one that does not fall on the apex — at which precision countless lines can be drawn through the site; and it depends on the metre, a unit defined in Europe millennia after the pyramids were built. [Rejecting P3] With thousands of visible stars, some set will align with any arrangement of structures on the ground, so an alignment selected after the fact carries no evidential weight — and even a deliberate alignment to Orion would show what the builders looked at, not who they were.