Given the surprisingly small feature size achievable, small enough to get diffraction, I wonder if anyone has tried making a playable CD out of chocolate or sugar.
A CD as a reflective coating to distinguish the pits, I don't know if that's mandatory though. Very thin gold foil is edible though (it just passes through the intestines, being chemically inert), so maybe a sugar disc coated with gold could be made to be playable, and still be edible?
As for the base material, I'm pretty sure that sugar has the better mechanical properties compared to chocolate. If you get it perfectly round and spin it up slowly, there shouldn't be too large forces acting upon it.
