1) The smallest unit of time is known as a zeptosecond, which is equal to one trillionth of one billionth of a second.

2) The Epic of Gilgamesh, originating from ancient Mesopotamia, is one of the oldest surviving works of literature and tells the story of the heroic king Gilgamesh and his quest for immortality. It explores themes of friendship, mortality, and the relationship between humans and the divine.

3) The phenomenon known as "black holes" occurs when matter is crushed into an infinitely small space, creating a gravitational pull so strong that nothing can escape.

4) The concept of compound interest can be attributed to the ancient Babylonians, who used it in their banking practices.