Christopher Lydon and Mary McGrath – the team behind the landmark radio program The Connection and the first-ever podcast in 2003 – are back on WBUR with Radio Open Source, a weekly conversation about arts, ideas, and politics that draws on the most intelligent people around Boston and the world. It’s a radio show in the best Boston tradition, and a podcast that connects with thoughtful listeners everywhere. In the past 18 months, Open Source has featured in-depth conversations you can’t hear anywhere else: like Michael Lewis on financial markets; Jeffrey Sachs, Ralph Nader, and Ray Kurzweil on automation and the global economy; Bill McKibben and Naomi Klein on climate change; with TED-style big ideas from the investor Jeremy Grantham and GoogleX engineer Sebastian Thrun; straight talk on politics from Lawrence Lessig and Zephyr Teachout and the Bay State’s own Barney Frank; and with Cornel West and a new generation of activists on Ferguson and police violence. Lydon and McGrath like to call Open Source “an American conversation with global attitude,” and now with a weekly show on WBUR radio, they’ll add some Boston flavors as well. Drawing on their roots here, they’ll remind you why Boston has been the capital of ideas in America since the heyday of Emerson and Thoreau in the 1840’s.