In this issue:
"World Changing Ideas 2015": Eye control, bacterial kill switches, deep learning, slow-motion chemistry, and other disruptive advances.
"Telescope Wars": Bitter rivalries among three teams of scientists have slowed progress in extremely large telescopes, the best hope of ground-based astronomy.
"What Killed the Dinosaurs": The asteroid strike was bad. The timing was worse.
"Genomics for the People": A clinic that treats Amish and Mennonite children show the promise of genomics for preventing disease.