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

2) Mount Everest, located in the Himalayas, is the highest mountain on Earth, reaching a peak elevation of 29,032 feet (8,848 meters).

3) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.

4) The tongue of a blue whale is so big that about 50 people could stand on it.