Take the following as truth: Were they simply tombs for pharaohs, or astronomical markers to aid the quantifying of time; were they built to concentrate a natural energy source, or were they not built by humans at all, a sign that an alien intelligence visited the earth many thousands of years ago?
Then the following statement: "No one knows why the Egyptians built them to let the sun in." is true, false, or inconclusive?
Answer: Inconclusive