For over five years, China has been building the Five-hundred-meter Aperture Spherical Telescope (FAST), a massive single-dish telescope that is the largest of its kind in the world. This summer they completed construction, and this past weekend, the telescope was finally switched on, manifesting China's hopes to reemerge as a scientific world leader. FAST is larger than the Arecibo Observatory, the radio telescope in Puerto Rico that used to hold the title of world's largest.