Did you know that the world’s first nuclear reactor is buried in a Southwest suburban forest preserve? Or that the site of a Civil War POW camp is now an apartment building at 35th and Cottage Grove? These spots and several others are featured in a new documentary airing Tuesday night on WTTW. It’s called “Chicago Time Machine” and it is produced by Geoffrey Baer and Dan Protess. This is the same team that has been involved in countless projects at the public television station, including “Chicago by El” and “Chicago’s Loop: A Walking Tour.” Baer’s projects have been a staple in Chicago television for over a decade and Geoffrey Baer and longtime producer Dan Protess join us for a conversation about this documentary and the art of these wildly successful and iconic television programs. Photo credit: Instagram @wbezchicago