The Stuff You Should Know podcast explores how things work, from the microscopic to the cosmic and quite a lot in between. The hosts, Josh and Chuck, have a pleasant back and forth approach that introduces a subject and then fills in the details. They keep the information general enough so the laymen among us (like me) don't get dazed and confused. Their off-topic sidebars drive me nuts, but maybe that's their point of differentiation. Twice-weekly, usually about three quarters of an hour in length.