Indicates wheelchair-accessible.

Indicates listening devices.

Events are free unless otherwise indicated.

Symposiums & seminars

Learn What It Takes to Be a Big Brother or Big Sister.

Big Brothers Big Sisters Southeastern Pa., 123 S. Broad St., Suite 2180; 215-790-9200 or

» READ MORE: www.bbbsepa.org

. 8 a.m. Tue., 6 p.m. Wed., noon Thu., 10 a.m. Sat.

Lectures & literature

Germany - The EU's New, Independent Powerhouse!

With H.E. Klaus Scharioth, Germany's ambassador to the United States, presented by the World Affairs Council of Philadelphia at the Loews Hotel, 1200 Market St.; 215-561-4700 or

» READ MORE: www.wacphila.org

for reservations. Admission for wine and hors d'oeurves reception and program $90, members $70; program only $40, members $25, students $20. Reception 6 p.m. followed by program at 6:45 Mon.

Lake Kariba: Fifty Years On. Lecturer is Chris Magadza, corecipient of 2007 Nobel Peace Prize. Presented by the Center for Environmental Policy at the Academy of Natural Sciences, 19th St. & Ben Franklin Pkwy.; 215-299-1108, www.ansp.org/environmental, or www.climatechangezimbabwe.eventbrite.com. Networking reception 6 p.m. followed by program at 6:30 Thu.

Honor Our Nation's History and Heroes. Tribute to our fallen service personnel at the National Constitution Center, 525 Arch St., Independence Mall; 215-409-6700 or www.constitutioncenter.org. Peace Corps' 50th Anniversary Showcase. Noon-3:30 p.m. Sun. Philadelphia's Navy Week Celebration. Tribute to the American flag narrated by Rear Adm. Kenneth J. Braithwaite. 11 a.m.-Noon Tue. Weekend commemoration, learn proper flag-raising protocol, storytelling, children's arts & crafts, Patriotic Karakoe. 10 a.m.- 3 p.m. Sat. & 5/30, Noon-3 p.m. Sun. Free with museum admission: adults $12, seniors (65 and older) $11, students with ID $11, children ages 4-12 $8, active military with ID and children younger than 4 free.

Authors

Free Library of Philadelphia.

Central Library (Montgomery Auditorium), 1901 Vine St.; 215-567-4341,

» READ MORE: www.freelibrary.org

. Pulitzer Prize-winner Geraldine Brooks,

Caleb's Crossing

, 7:30 p.m. Tue.

Screenings

Beethoven Symphony No. 9.

Philadelphia Orchestra Concert Series. Bryn Mawr Film Institute, 824 W. Lancaster Ave; 610-527-4008 or

» READ MORE: www.brynmawrfilm.org

. Adults $20, BMFI members $18, students and seniors $10. 2 p.m. Sun., 12:30 p.m. Mon.

For a complete calendar of events, go to "What's Happening," at http://www.philly.com/philly/calendar