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

2) The Federal Reserve System, often referred to as the Fed, is the central banking system of the United States.

3) The speed of light is approximately 299,792,458 meters per second.

4) The world's oldest university, Al-Qarawiyyin, was founded in 859 AD and is located in Fez, Morocco.