How to Discover a Galaxy with a Telephoto Lens - Issue 32: Space
▻http://nautil.us/issue/32/space/how-to-discover-a-galaxy-with-a-telephoto-lens
Like countless so-crazy-it-just-might-work schemes, this one began with a gripe session. In the fall of 2011, Roberto Abraham and Pieter van Dokkum were commiserating at a Nepalese restaurant in Toronto. Over curry and rice—and a generous quantity of beer—the old friends bemoaned a problem they’d discussed many times before. As observational cosmologists, they shared a professional interest in how galaxies are born and evolve. The leading theory, known as hierarchical galaxy formation, describes this growth as a long scaling up, from little to big, simple to complex. In the beginning, just a few thousand years after the Big Bang, almost all mass was dark matter—that mysterious, unseen counterpart to ordinary, luminous matter. But dark matter didn’t spread evenly across the infant universe, (...)