The crumbs and debris Bumbershoot have been swept away, but Seattle Center isn’t yet done with our (Indian) summer. Today’s Big Birthday Bash continues the 50th-anniversary commemoration of our World’s Fair with a host of family and children’s activities. That means food, entertainment, games, face-painting, and the like, with tents and stations set up all around campus. Among some of the other attractions you shouldn’t miss, all part of the Next 50 celebration, are a brick wall made of Jell-O (!) by artists Lisa Hein and Robert Seng, a special room full of vintage video games at the Center House (yes, you can play them; though your kids may be confounded by those 8-bit displays), a SIFF screening of It Happened at the World’s Fair, vintage car show, an appearance by the Seafair pirates, work from the Pilchuck Glass School, music by jazz vocalist George A. Santino, and MOHAI’s display of Century 21 memorabilia at the International Fountain Pavilion. Get to the Center early, and you can attend the celebration of J.P. Patches at McCaw Hall (11 a.m., $5). Then, after shedding a few tears, go have some fun with the kids. It’s what J.P. would’ve wanted. BILL MARINER

Sat., Sept. 8, 11 a.m.-3 p.m., 2012