U.S. President Barack Obama pumps air pressure into Extreme Marshmallow Cannon designed by Joey Hudy (L) of Phoenix, Arizona, before firing a marshmallow across the State Dining Room of the White House during the second White House Science Fair in Washington February 7, 2012. The fair celebrates the achievements of student winners of a broad range of science, technology, engineering and math (STEM) competitions from across the country.

REUTERS/Kevin Lamarque (UNITED STATES – Tags: SCIENCE TECHNOLOGY SOCIETY EDUCATION POLITICS)