When we look up into the sky at night we see—not a lot if we live in a city, maybe the moon and some bright stars plus a planet or two. However, if we leave the bright city and its street lights behind, the picture changes dramatically. We see thousands of stars, and after watching a while we can discern patterns: we might notice that the stars are not evenly distributed. We might see that there is a band of stars right across the sky, this is our galaxy. If we have binoculars to aid our star gazing, we might notice that some of the dots we thought were stars are indeed tiny blobs, little “nebulae” or galaxies like our own. Using more sophisticated and bigger telescopes reveals even more structure in the distribution of galaxies on the largest visible scales. We are still learning more about the universe, as astronomers, with more sophisticated equipment, continue to make new observations at wavelengths beyond those that are visible to the naked eye, for instance observing in the radio and microwave wavelengths.