President Barack Obama participates in a science experiment with... News PhotoBarack Obama,Horizontal,Human Interest,International Landmark,Person in Education,Science,Scientific Experiment,US President,USA,Washington DC,White House - Washington DCPhotographer Collection: The Washington Post 2013 The Washington PostWASHINGTON DC: APRIL 22 President Barack Obama participates in a science experiment with Northeast High School students Payton Kaar, 18, and Kiona Elliott, 18 of Oakland, Florida at the White House in Washington, D.C. on April 22, 2013. Lemelson – MIT Program: InvenTeams Teens design pedal-powered filtration system: High-schoolers Payton Karr and Kiona Elliot, from Oakland Park, Florida, led a team of inventors who designed a collapsible, transportable, bicycle-powered emergency water-sanitation station that filters E. coli and other harmful pathogens from contaminated water. In emergencies, the device can be assembled and disassembled in under an hour, and can produce enough water to hydrate 20 – 30 people during a 15 hour period. Payton, Kiona, and their Northeast High School classmates received a 2012 InvenTeam grant from the Lemelson-MIT Program, which supported their development of the innovative design. Both Payton and Kiona intend to be the first in their families to attend college. President Barack Obama hosts the White House Science Fair to celebrate the student winners of a broad range of science, technology, engineering and math (STEM) competitions from across the country. (Photo by Marvin Joseph/The Washington Post via Getty Images)