Amanpour: Dave Cullen, Tom Mauser, Jess Philips and Neil deGrasse Tyson

President Joe Biden has called for Congress to enact stricter gun control measures after another deadly shooting rocks America, this time in Boulder, Colorodo. Dave Cullen, author of "Columbine" and "Parkland: Birth of a Movement", and Tom Mauser, whose teenage son was killed in the Columbine massacre, join Christiane Amanpour to discuss. Then in the aftermath of the Sarah Everard murder, British Labour MP and Shadow Minister for Domestic Violence and Safeguarding Jess Philips reflects on this moment of opportunity for ending violence against women once and for all. And our Walter Isaacson speaks to renowned physicist Neil deGrasse Tyson about his new book, "Cosmic Queries," co-authored with fellow physicist James Trefil. He explains his thirst to explore the really big questions of the universe.   To learn more about how CNN protects listener privacy, visit cnn.com/privacy Learn more about your ad choices. Visit podcastchoices.com/adchoices