the entire universe was simply a glowing opaque fog in every direction you looked. The Sun and all other stars behave this way, too. As the temperature drops, particles move more and more slowly. And so right about then, when the temperature of the universe first dipped below a red-hot 3,000 degrees Kelvin, electrons slowed down just enough to be captured by passing protons, thus bringing full-fledged atoms into the world.
