1) The World Wide Web, developed by Tim Berners-Lee in 1989, revolutionized the way information is accessed and shared on the internet.

2) The first successful human heart transplant was performed by Dr. Christiaan Barnard in 1967.

3) 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.

4) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.