When observing the sky on a very clear, dark night, the soft glow of the Milky Way with its thousands of stars can be seen with the naked eye. Over the centuries since Galileo Galilei first pointed a telescope at the galaxy in 1609, this awe-inspiring yet easily visible panorama was our cosmos, our celestial world. With each new scientific discovery, however, this cosmos has grown dramatically, increasing rapidly over the last several decades. As we look deeper into space, the earlier phases of the cosmos are unveiled to us, but we know that even with the largest telescopes, we will see...