1) The highest-grossing concert tour of all time is U2's "360° Tour," which earned over $735 million in ticket sales.

2) Cyclones are fueled by warm ocean waters and atmospheric conditions that allow the formation of thunderstorms.

3) The invention of the printing press by Johannes Gutenberg in the 15th century revolutionized the spread of knowledge and played a key role in the Renaissance.

4) The human body contains enough carbon to make over 9,000 pencils.