Other unsolved mathematical mysteries are akin to the branches of trees. The trees themselves—fields within the wider subject of math —are strong and towering, rooted firmly in established findings.

A multitude of mysteries remain unsolved about the ancient Greek world, providing more questions than answers.

ALBUQUERQUE, N.M. (AP) — The FBI is sending extra agents, analysts and other personnel to field offices in 10 states over the next six months to help investigate unsolved violent crimes in ...