1) The speed of light is approximately 299,792,458 meters per second.

2) The ongoing conflict in Syria, which began in 2011, has resulted in a humanitarian crisis, displacement of millions of people, and international efforts to bring about a resolution and provide aid to those affected.

3) The highest-grossing film of all time is "Avengers: Endgame," which has earned over $2.79 billion at the global box office.

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