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After moving from his home in rural Maine to Brooklyn, filmmaker Ian Cheney says he lost his childhood fascination with astronomy. That’s not surprising in a city where lit-up streets and buildings render stars nearly invisible. Light pollution serves as a frequent boogeyman of the modern age, a metaphor for critics who say we’ve lost touch with nature’s simple wonders. But what if the cosmos weren’t obscured for future generations of urbanites? Would seeing the Big Dipper really enrich their lives? Has constant exposure to artificial light somehow impaired city dwellers? In The City Dark, showing tonight courtesy of the Environmental Film Festival, Cheney attempts to address those questions. An ardent eco-documentarian (he co-wrote and -produced the 2007 corn-industry exposé King Corn), Cheney has avoided being lumped with alarmists such as Davis Guggenheim (An Inconvenient Truth) by substituting emotional manipulation with sincere curiosity, subtle self-awareness, and welcome humor. (Matt Bevilacqua) 7 p.m. at E Street Cinema. $15


The local music blog All Things Go and the New York label Neon Gold host their second All Things Gold concert at U Street Music Hall tonight, featuring the fast-rising duo The Knocks, who split their work between above-average dancehall compositions and remixing other artists’ hits, like their take on Wale and Lady Gaga‘s 2009 track “Chillin.” Also in the lineup is The Knocks’ newest protege, St. Lucia, a South African expat who so far this year has succeeded in keeping his real name a secret, but his second single, “All Eyes on You,” is the stuff picturesque late-summer beach parties—not that you’ll be having any this weekend—are made of. 9 p.m. at U Street Music Hall. $13.


Got a knack for the funny pages? Warren Bernard, the director of Small Press Expo (Sept. 10 in Bethesda), and a prolific collector of cartoons and comics, discusses Drawing Power: A Compendium of Cartoon Advertising, his new book with comic strip historian Rick Marschall about the use of characters like Popeye and Annie as pitchmen, at Politics & Prose at 7 p.m. Free.


Back to the Future at Stead Park at 8:30 p.m., because why not? Free.


A tribute to Simon & Garfunkel at Strathmore.