A Mysterious Cosmic Recipe
Today we address the composition of the universe, in the final essay of our trilogy on cosmic questions.
As the great German astronomer Johannes Kepler once wrote in the early 17th century: "When the storm rages and the shipwreck of the state threatens, we can do nothing more worthy than to sink the anchor of our peaceful studies into the ground of eternity."
So, let's sink our anchor, once again, into the study of the heavens. Previously, we discussed both what an expanding universe means, and whether we can make sense of the hardest question of them all — the origin of all things. Our question today? How much do we know of the stuff that fills up the universe?
In the interest of clarity, I'll break the cosmic recipe into its three main ingredients: the stuff we are made of; dark matter; and dark energy.
The stuff
