The one-act play is the poetry of the stage. Compact, concise, the one-act is the distillation of theater and it ain't easy to write. But the winners of the Y-Rep Teen One-Act Playwriting Contest persevered, and now, they have awards to show for their hard work. More important, these young dramatists get to enjoy several public performances of their prize-winning efforts courtesy of the Y-Rep Teens at 7:30 p.m. Thursday, Friday and Saturday (May 11 through 13) at the West County Family YMCA (16464 Burkhardt Place, Chesterfield; 636-532-6515). Your $5 admission fee gets you four plays: Joe Decker's "Ping Pong with Jesus" (the first-place winner, by the way), "Wedding at the Smiths'" (a group effort), "The After Party" by Elliot Gallion and Niels P. Zussblatt's "Physics for Poets 101." Ah, see how Zussblatt ties things all together? Poetry of the stage + physics of poets = physics saving the day once again.