Tom MacDonald talks to volunteers at this year’s MLK Day of Service, and then we talk to Todd Bernstein, founder of the Day of Service. Maiken Scott reports on the cancellation of this year’s professional bike race in Philadelphia. Benjamin Herold talks to parents incensed by the Philadelphia School District’s decision to make Penn Alexander Elementary School a lottery school. Franklin Institute Chief Astronomer Derrick Pitts joins us for Skytalk. And Chris Satullo says national discourse over gun violence won’t necessarily yield meaningful reform.