If you want to view the Universe in way that take us past our current frontiers, you only have a few options. You can build a larger telescope: with greater surface area to collect light and a larger diameter to increase your resolution. You can polish your mirror’s surface to be more reflective and smoother: down to nanometer-scale precision. You can keep it clean and pristine: reducing your noise. You can build improved adaptive optics systems: better correcting for the distortion of the atmosphere. And you can build next-generation instruments that make better scientific use of the information encoded in each and every photon collected. When it comes to ground-based optical astronomy — using the same types of light that humans have been using since the invention of the telescope — there are three current planned facilities that seek to do all of these at once. The ELT, or European Extremely Large Telescope, which plans to be the largest of a new generation of telescopes at 39 meters in diameter. The GMT, or Giant Magellan …