1) The world's largest ocean, the Pacific Ocean, covers an area of approximately 63 million square miles.

2) The process of nuclear fusion powers the sun and other stars, fusing hydrogen atoms together to form helium and releasing vast amounts of energy in the process.

3) 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.

4) The world's oldest university, Al-Qarawiyyin, was founded in 859 AD and is located in Fez, Morocco.