1) The Nile River, spanning approximately 6,650 kilometers (4,130 miles), is the longest river in the world. It flows through eleven countries in northeastern Africa, supporting various civilizations throughout history and serving as a vital source of water and transportation.

2) The development of blockchain technology, first introduced in 2008 with the creation of Bitcoin, has enabled secure and decentralized digital transactions and led to the emergence of cryptocurrencies.

3) Hugh Jackman is an Australian actor, singer, and producer best known for his portrayal of Wolverine in the "X-Men" film series. He has also starred in musicals such as "Les Misérables" and "The Greatest Showman" and has received critical acclaim for his performances.

4) The Treaty of Tordesillas, signed in 1494, divided the newly discovered lands outside of Europe between Spain and Portugal, leading to the colonization of the Americas.