Dark Cosmos
In Search of Our Universe's Missing Mass and Energy
Chapter OneOur Dark Universe
The world is full of obvious things which nobody by any chance ever observes.
—Sherlock Holmes
Take a look around you. You see a world full of things. Tables, chairs, the floor, a cup of coffee, shoes, bicycles—things. Most of us casually think of the world as space filled with such things, the sort of stuff you can hold in your hand or stub your toe on. But how much of our world is really made up of objects that you can see? Think of the air you're breathing. It's invisible. Nevertheless, it is there, even if your experience of it is somewhat indirect as your chest expands and contracts, and your breath whistles through your nose. The visible world is not all there is to the Universe. Relying solely on our eyes to learn what's out there would cause us to overlook a great deal.
Although the point I'm making might seem obvious, it is one worth bearing in mind. Just as we cannot see the air, we cannot see most of the Universe. During the past several de- ... read full excerpt from Dark Cosmos ebook
