1) International relations encompass the study of relationships between nations, including diplomacy, treaties, and foreign policy. It examines the interactions and dynamics among different countries in the global arena.

2) The concept of federalism involves the division of powers between a central government and regional or local governments, allowing for shared governance and autonomy for different levels of administration.

3) The Earth's core is hotter than the surface of the Sun.

4) The first bank in the world, Banca Monte dei Paschi di Siena, was established in Italy in 1472 and is still in operation today.