1) The concept of self-driving cars, or autonomous vehicles, is being actively developed by companies such as Tesla, Google (Waymo), and Uber.

2) A single bolt of lightning can heat the surrounding air to temperatures five times hotter than the surface of the sun.

3) Automated Teller Machines (ATMs) allow individuals to perform banking transactions, such as withdrawing cash, outside of traditional bank branches.

4) 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.