1) Serena Williams, an American tennis player, has won a total of 23 Grand Slam singles titles, making her one of the most successful players in the history of the sport.

2) The first commercial GPS (Global Positioning System) was launched in 1989 and provided accurate positioning and navigation capabilities to users worldwide.

3) The ancient city of Rome was founded in 753 BC and went on to become one of the most powerful and influential civilizations in history.

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