Finally, invoking the maxim that "Extraordinary claims require extraordinary evidence", what evidence is there that proves the ancients understood the speed of light and the length of 1 hz and what evidence is there that shows how they had actually determined these values BEFORE building Giza?
Again, I cite specific evidence too lengthy to repeat here in chapter sixteen of my book The Cosmological Origins of Myth and Symbol.
The upshot of the argument (based on explicitly-stated Dogon traditions that correlate in several different ways to the Egyptian) is that the pyramids of Giza are meant - as Robert Bauval claims - to point us to Orion. This was devised as a way of drawing our attention to an important but hard-to-see structure that can provide a conceptual link between the processes of the microcosm and those of the microcosm. In other words, evidence to prove the phrase "As Above, So Below").
That structure measures 440 light years by 280 light years - the same as dimensions of the Great Pyramid in cubits. For those who may not know, it is from the dimensions of the Great Pyramid that we infer the size of the cubit.
The example is a demonstration that the Egyptians knew the dimensions of this structure in light years and had decided to refer to it using the cubit to represent light-years BEFORE they built Giza.