1) The process of nuclear fusion powers the sun and other stars, fusing hydrogen atoms together to form helium and releasing vast amounts of energy in the process.

2) The shortest scheduled commercial flight lasts just 1.7 miles and connects two Scottish islands, Westray and Papa Westray.

3) Honey never spoils. Archaeologists have found pots of honey in ancient Egyptian tombs that are over 3,000 years old and still perfectly edible.

4) Mountains are important water sources, as they capture and store precipitation, feeding rivers and supporting ecosystems downstream.