1) The ancient city of Pompeii was preserved under layers of volcanic ash after the eruption of Mount Vesuvius in 79 AD, providing valuable insights into Roman life.

2) Michael Jackson's album "Thriller" is the best-selling album of all time, with estimated sales of over 66 million copies worldwide.

3) The name "Bluetooth" comes from the 10th-century Danish king, Harald Bluetooth, who united Denmark and Norway.

4) The deepest part of the ocean is the Mariana Trench, reaching a depth of about 36,070 feet (10,994 meters).