ART: Yerba Buena Center for the Arts debuts the first night in their new Smart Night Out series, which will explore the concept of quiet as it relates to contemporary art and performance. Visitors will be given the opportunity to meditate in the galleries, participate in a silent dance party, enjoy culinary delights, experience "eardrum preserving ambient sound art," and engage in workshops with artists featured in YBCA's Daily Lives exhibit. (7 to 11:30 p.m., Yerba Buena Center for the Arts, 701 Mission Street)

MUSIC: Tonight's SF Popfest event features an epic Slumberland Records Showcase, which includes 14 Iced Bears, Phil Wilson (of The June Brides), Neverever, The Art Museums, Devon Williams, Brilliant Colors, Terry Malts, Sea Lions, Kids on a Crime Spree, English Singles, and DJ Kid Frostbite. (5 p.m., Rickshaw Stop, 155 Fell Street)

FILM: The new documentary Into Eternity explores the world's first permanent nuclear waste repository in Finland, which will soon be sealed off and never opened again. The film poses difficult questions, such as how can we ensure it will be sealed off for 100,000 years -- the amount of time the waste will still be radioactive, how can we warn our descendents of the waste, what languages will they understand, and will they respect the instructions? (5:30, 7, and 8:45 p.m., Roxie Theater, 3117 16th Street)