1) The Dead Sea, located between Jordan and Israel, is the lowest point on Earth's surface. Its saltwater is so dense that people can easily float on its surface.

2) The phenomenon known as "black holes" occurs when matter is crushed into an infinitely small space, creating a gravitational pull so strong that nothing can escape.

3) The concept of compound interest can be attributed to the ancient Babylonians, who used it in their banking practices.

4) The world's largest volcano, Mauna Loa in Hawaii, is also one of the most active.