1) The highest mountain in Africa is Mount Kilimanjaro, standing at 19,341 feet (5,895 meters) tall.

2) The sitcom "Friends" is known for its iconic Central Perk coffee shop, where the main characters often gather.

3) The Appalachian Mountains, running along the eastern coast of the United States, are one of the oldest mountain ranges in the world.

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