1) 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.

2) Norse mythology, originating from the Scandinavian region, features gods and mythical creatures like Odin, Thor, Loki, and Valkyries. It explores themes of heroism, destiny, and the battle between gods and giants, with intricate tales recorded in texts such as the Prose Edda and Poetic Edda.

3) The first commercially successful video game was "Pong," released in 1972 by Atari.

4) The Internet of Things (IoT) refers to the network of physical devices, vehicles, appliances, and other objects embedded with sensors, software, and connectivity.