In ''Evolution,'' Julianne Moore and Co. fight aliens with Head & Shoulders. Would the dandruff shampoo's selenium really kill nitrogen-based critters?
Stop scratching your head. ''Selenium has no negative effect on nitrogen,'' says Harvard University lab coordinator Gregg Tucci. But what if 500 gallons were given rectally, as in the flick? ''It's toxic to humans in large amounts,'' he admits. ''I just don't know that sticking a bunch of selenium up a nitrogen-based life-form's butt will do anything, other than getting him really mad.'' Adds an H&S rep: ''We have no experience with how the product affects extraterrestrials.''
(Send your queries to BurningQuestions@ew.com.)