1) 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.

2) The concept of human rights advocates for the basic rights and freedoms to which all individuals are entitled, regardless of their nationality, ethnicity, religion, or other characteristics.

3) Brad Pitt is an American actor and film producer. He has starred in a wide range of films, including "Fight Club," "Inglourious Basterds," and "Once Upon a Time in Hollywood," and has received critical acclaim and numerous awards for his performances.

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