1) Sir Elton John, born Reginald Kenneth Dwight, is an English singer, songwriter, and pianist. With a career spanning over five decades, he is one of the best-selling music artists in the world and has received numerous awards and accolades for his contributions to music.

2) 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.

3) The Triple Double in basketball refers to a player achieving double-digit totals in three of the following statistical categories: points, rebounds, assists, steals, or blocks.

4) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.