1) The Earth's core is hotter than the surface of the Sun.

2) The world's largest desert is the Antarctic Desert, covering around 5.5 million square miles.

3) The Industrial Revolution led to significant urbanization, as people migrated from rural areas to cities in search of employment in factories.

4) The concept of 3D printing, also known as additive manufacturing, was first introduced in the 1980s and has since revolutionized prototyping and small-scale production.