Today’s teenagers have grown up with social network technologies that affect how they think about privacy, companionship and the nature of friendship. Sherry Turkle, MIT’s Abby Rockefeller Mauzé Professor of the Social Studies of Science and Technology, will speak about intimacy without privacy, democracy without privacy. With such technology, are we more together or alone? A reception and book signing will follow the 5 p.m. lecture in the Salomon Center for Teaching, De Ciccio Family Auditorium.