In a blog post, Neal Stephenson says it's time that people develop a new medium, "one in which three-dimensionality is a reality and not just an illusion laboriously cooked up by your brain." Madeleine Ball/NPR hide caption

itoggle caption Madeleine Ball/NPR

Chris Kyle, retired Navy SEAL and bestselling author of the book American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History, in April 2012. He was killed Saturday. Paul Moseley/Fort Worth Star-Telegram /MCT /Landov hide caption

itoggle caption Paul Moseley/Fort Worth Star-Telegram /MCT /Landov