This April 21-29, the MIT Museum will help run a citywide Cambridge Science Festival. The first of its kind in New England, the festival will celebrate the great science going on behind the doors of labs and companies in what museum director John Durant, who dreamed up the project, calls a “science city.” As many as 180 events, most of them proposed by the public, will be organized around such themes as “energy” and “science in everyday life.” The schedule includes a DNA lab activity at Biogen Idec, a pharmaceutical biotech company in Tech Square; a live broadcast of NPR’s Science Friday; a “geology of Cambridge” tour run by MIT’s earth and atmospheric-sciences department; and a showcase of undergraduate research. See the complete schedule online at cambridgesciencefestival.org.