At first, the universe was like a hot stew. Instead of carrots and potatoes, it had particles. As the soupy universe cooled, ...

The solid inner core at the center of the Earth, surrounded by the outer core, mantle and crust. Here’s why: While it is well known that a material must be at or below its freezing temperature to be ...

Billions of years ago, in the giant disk of dust, gas, and rocky material that orbited our young sun, larger and larger bodies coalesced to eventually give rise to the planets, moons, and asteroids we ...