1) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.

2) Michael Phelps, an American swimmer, has won a total of 28 Olympic medals, including 23 gold medals, making him the most decorated Olympian of all time.

3) Robert Downey Jr. is an American actor known for his portrayal of Iron Man in the Marvel Cinematic Universe. He has also starred in films such as "Sherlock Holmes," "Chaplin," and "Tropic Thunder," and has received critical acclaim and commercial success for his performances.

4) 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.