M.I.T. Museum Main Gallery
265 Massachusetts Avenue, Cambridge, (617) 253-4444
web.mit.edu/museum

($5; age 5 to 18, $2; closed Monday), you’ll find robots, 3-D holograms, including one of the remains of a 2,000-year-old man discovered in a bog in England, and an exhibition of photographs that capture instants in time like when a bullet explodes through an apple.