Resumen de Letters.

Byron Bowman, Chuck Simmons, Ken Adams, David L. Hardie, Andrew Benton, Willie Dickerson

• Letters to the editor are presented in response to several articles in the April 2015 issue, including "Burning Rings of Fire" by Joseph Polchinsky, "How to Survive a Cyberwar" by Keren Elazari, and "Conquer Yourself, Conquer the World" by RoyF. Baumeister.