William Beebe, the naturalist, used to visit fellow nature-lover Theodore Roosevelt. Often, after an evening of good conversation at Roosevelt’s Sagamore Hill home, they would walk across the lawn in the darkness. They would look up at the stars, point out the constellations, and carry on a conversation something like this: “There’s the spiral galaxy of Andromeda! Did you know it was as large as our own Milky Way? Over a hundred billion stars. And every one of them is larger than the sun. 750,000 light-years away. And there are a hundred million more galaxies like it out there!”
