Framingham State University’s Christa McAuliffe Center will hold its second annual Science on State Street festival on April 23, 10AM-2PM, on its campus (directions).  It’s free and open to all ages, with hands-on activities (in biology, chemistry, physics, food science, robotics and engineering), presentations by FSU faculty and invited scientists, conversations and performances that explore the interaction between science and the arts, and planetarium programs.  There will be a live sky planetarium presentation at 10AM for children 5 and younger, a do-it-yourself Rube Goldberg machine, and opportunities to build a battery, program a robot, interact with exotic insects, explore chemistry, and meet the author of “The Secret Case of the Space Station Stowaways.”