As our centennial series continues, Robert Coker, author of the book Roller Coasters: A Thrill Seeker's Guide To The Ultimate Scream Machines (Main Street, 2002) and Douglas Barnes, co-hosts of The Season Pass podcast, talk about the history of roller coasters, from the "Golden Age" of 1920's wooden coasters like Coney Island's Cyclone through modern steel "strata coasters," like the late lamented Kingda Ka, which was recently imploded to make room for a new ride.