The International Atomic Energy Agency (IAEA) has invited Member States to participate in the ConvEx-3 nuclear emergency exercise, scheduled for 14–15 May 2025, in Romania. The exercise, to be held at ...

Fire trucks and an emergency response helicopter stand ready during a national nuclear emergency exercise in Romania in October 2023. (Photo: C. Torres Vidal/IAEA) The IAEA invites Member States to ...

A polygon is regular if it is uniform and its faces are all alike. The regular convex polyhedra are the five Platonic solids, which have been known since classical Greece. The ancient Greek ...

Besides the regular and semiregular solids, there are just ninety-two other convex polyhedra with regular faces. In 1966, the American mathematician Norman W. Johnson, a student of H.S.M. Coxeter at ...