1) The invention of the transistor by Bell Laboratories in 1947 revolutionized electronics and paved the way for the development of smaller, more efficient electronic devices.

2) The concept of gravity was famously described by Sir Isaac Newton after an apple fell on his head.

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 most-watched TV series finale in the United States was "MAS*H," with an estimated 105 million viewers.