1) In Norse mythology, the World Tree, known as Yggdrasil, is a massive ash tree that connects the nine realms of existence. It is considered the center of the cosmos and serves as a conduit between different realms, including Asgard (realm of the gods), Midgard (realm of humans), and Helheim (realm of the dead).

2) Emma Stone is an American actress known for her roles in films such as "La La Land," "Easy A," and "The Help." She has received critical acclaim and several awards, including an Academy Award, for her performances, establishing herself as a talented and versatile actress.

3) The New York Stock Exchange (NYSE) is the largest stock exchange in the world.

4) The first computer mouse was invented by Douglas Engelbart in 1964 and consisted of a wooden shell and two metal wheels.