the mathematics of cartographic projections possibly
but this information was really a military secret not that long ago. same as cryptography is right now!
which annoys me personally becuase I wish to learn more/better about the mathematics behind information technology and cryptography. but this is considered 'sensitive' understanding so the quantity of people that are ever taught this stuff is tightly controlled; not to say that it's difficult stuff to begin with and any efforts to make it more widespread and accessible are often derailed in education comitees and so on. but I should stop before I get any more paranoid
but this information was really a military secret not that long ago. same as cryptography is right now!
which annoys me personally becuase I wish to learn more/better about the mathematics behind information technology and cryptography. but this is considered 'sensitive' understanding so the quantity of people that are ever taught this stuff is tightly controlled; not to say that it's difficult stuff to begin with and any efforts to make it more widespread and accessible are often derailed in education comitees and so on. but I should stop before I get any more paranoid