Pi Day at the Carnegie Museum turned to physics Saturday as the week-long celebration wrapped up. A good crowd turned out to learn about everything from light refraction to center of mass and pressure differentials. Pictured above, Dave Johnson, a junior at Wabash College, demonstrated center of mass with a plastic bird with weighted wings. Pictured right. Carrie Pool, 11, sixth grader at Crawfordsville Middle School launched an angry bird as part of the hands-on exhibit. She said she was having fun and her teacher, Mrs. Hudson, was offering extra credit in science class for attending the museum.