Each year, on the Friday After Thanksgiving, the MIT Museum hosts a hugely collaborative Chain Reaction in which simple or complex contraptions built by participating teams are joined into one massive Rube-Goldberg-esque chain reaction viewed by over 1500 attendees.  (See videos from 2013 and 2014.)  This year, the 19th annual F.A.T. Chain Reaction will be on November 25, 1-4PM, and will be based on the theme “Symmetry.”  The public can view contraptions and talk with teams 1PM-3PM, and the chain reaction will start at 3:30PM.  Buy tickets online through November 24, or in person on November 25 at the MIT Museum (starting at 10AM) or Rockwell Cage (starting at 1PM).  There’s still time to register a team to participate by building a link in the chain.