Journalist Andy Kroll joins us to discuss his story in The California Sunday Magazine, “The Great Exception: California vs. Trump,” the first part in a series about the relationship between California and Donald Trump’s Washington. Journalist Sam Apple joins us to discuss his recent article for Wired, “The Young Billionaire Behind the War on Science,” a profile of billionaire John Arnold who’s pledged half his fortune to debunking scientific research. Apple will be joined by Scientist Tim Errington of Open Science Framework, who is the project lead on the cancer replication project mentioned in Apple’s story. Actor Giovanni Ribisi, star of the new Amazon series, “Sneaky Pete,” joins us to discuss the show and his career. This week's Please Explain is all about social activism and volunteering. We'll be joined by Ami Dar, founder and executive director of Idealist, and Alex Kouts, Head of Product at Countable, to answer your questions about civic engagement.