Sharing a New Song brings together, albeit in a small way, the people of the two legendary world superpowers, the United States of America and the former Soviet Union. During the Cold War, the conflict extended beyond political concerns and manifested itself most noticeably in the alarmingly negative opinions that citizens of the two countries held about each other.

Thanks in part to the documents released by Edward Snowden, the true scale of the National Security Agency's scope and power is coming to light. Besides spending billions to ingest and analyze the worlds' electronic communications, the NSA has set out to dominate a new battlefield, cyberspace. Nova examines the science and technology behind cyber warfare and asks if we are already in the midst of a deadly new arms race.

Violence is all over the news. But some say this is the most peaceful time in history. Journey through time and the human mind to investigate whether violence has declined. And witness how people are working to stop violence today. "From suicide bombings to mass shootings, the nightly news can make it seem like we live in the most violent of times. In barely a century, humanity has seen two world wars and the slaughter of millions by pitiless tyrants,...