On a clear, moonless night, far away from the glow of city lights, the universe opens up above me. Pinpricked with ancient points of light, the night is breathtaking. Lying on the ground and looking up at the sky on clear nights, it’s obvious that the universe is three dimensional. I’ve had moments of vertigo. I’ve had moments of awe. Our galaxy sweeps away in the bright clear arc of the Milky Way, so beautiful and complicated and ancient and unlikely that it makes my heart race. The sky is unforgettable.