This Monday President Obama invited young inventors to the White House to show off their inventions at the annual White House Science Fair (see articles in The Miami Herald and The New York Times). Payton Kaar and Kiona Elliott, two young women from Northeast High School in Broward County, Florida, brought their pedal-powered water filtration system. They convinced the president to pedal for a few minutes, as shown here (he hops on the bike around 6 min., 30 sec.) and provided a great explanation of how the filtration system worked. Obama pronounced the invention “Outstanding.” Congratulations Payton and Kiona!