Egyptian pyramids

I am not an expert in Egyptian pyramids but it seems that the angle of Egyptian pyramids is large enough to keep the pyramid not covered by a sand from sandstorms for centuries. For a free pile of sand the angle of repose is about 30-35 degrees (approximated from a friction coefficient). For a pile of sand growing near a faces of a pyramid stones this angle seems to be greater. Thus, it is reasonable to set up the angle of a pyramid as more than 40 degrees to keep it resistant to the sand storms (and eternal, in fact).

Why do crickets chirp?

Hallo! I am looking for a student(?) who is interested in developing a research on some aspect of a voice emission by creatures in their environment. The work is partially done but some acoustic measurements and an analysis of it as well as theoretical investigations and programming is needed. The work has been done with collaboration with an ornithologist and a programmer. I hope that some very interesting aspect of the chirp and singing would be revealed and published.
Not only an UMCS student is invited. Everyone who is skilled in physics and enthusiastic in nature research is possibly an appropriate person here.