Indicates wheelchair-accessible.

Indicates listening devices.

Events are free unless otherwise indicated.

Symposiums & seminars

Judicial Activism in the Supreme Court. Visiting scholar Geoffrey Stone is joined by federal Judge Kent Jordan for an examination of the history of judicial activism. National Constitution Center, 525 Arch St; 215-409-6700 or www.constitutioncenter.org. Reservations required. 6:30 pm Mon.

Drilling for Natural Gas in the Marcellus Shale: What It Means for Pennsylvania. Academy of Natural Sciences, 19th & Pkwy; 215-299-1000 or www.ansp.org. 6 pm Wed.

Schools for the Colored, a photography exhibit by Wendel A. White. White's images of segregated schoolhouses from before and just after World War II document the lost history of African American education in New Jersey. Willingboro Public Library, 220 Willingboro Pkwy; 609-877-6668. Exhibit runs Mon-Jun. 30.

Flag Fest 2011, a Turn-of-the-Century Celebration. Visitors are invited to step back in time to those celebrations when the dawn of the 20th century filled Americans with excitement. A Victorian-style street fair takes over Arch St. Betsy Ross House, 239 Arch St; 215-629-4026 or www.betsyrosshouse.org. Patriotic Pet Parade 2 pm. Flag Fest 10 am-5 pm. Sat.

Authors

Free Library of Philadelphia. Central Library (Montgomery Auditorium), 1901 Vine St; 215-567-4341 or www.freelibrary.org. Oscar Hijuelos, Thoughts Without Cigarettes: A Memoir, 7:30 pm Tues Eli Pariser, The Filter Bubble: What the Internet Is Hiding from You, 7:30 pm Thurs.

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

calendar