1) The world's largest desert is the Sahara Desert in Africa, covering an area of about 3.6 million square miles (9.4 million square kilometers).

2) The first consumer digital video recorder (DVR), the TiVo, was introduced in 1999 and allowed users to record and store television programs for later viewing.

3) 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).

4) Cristiano Ronaldo is a Portuguese professional soccer player widely regarded as one of the greatest footballers of all time. He has won numerous awards, including multiple FIFA Ballon d'Or titles, and has played for top clubs such as Manchester United, Real Madrid, and Juventus.