On Saturday, the Maine Science Festival hosts its rescheduled 5 Minute Genius event at 7 p.m. at the Bangor Opera House. Also on Saturday, a cappella ensemble Straight No Chaser brings its Yacht Rock Tour to the Collins Center for the Arts in Orono at 8 p.m., and comedian Alex Giampapa and guests perform at 6 p.m. at Queen City Cinema Club in Bangor. On Sunday, the Maine Mayhem Film Festival, featuring an array of Maine-made short films, is set for 2 p.m. at the Bangor Arts Exchange. And, of course, Sunday is Mother’s Day — get those brunch or dinner plans squared away now.