(Image Credit: Jewel Samad/AFP/Getty Images)

President Obama today praised the work of student scientists and engineers at the third annual White House Science Fair, saying, "This stuff is really cool."

"I want to thank these incredible young people for explaining to me what the heck is going on," Obama joked in brief remarks at the White House.

Thirty students from across the country came to the White House today to show off their winning projects from science, technology, engineering and math competitions.

The president, who described the event as one of his personal favorites, got a first-hand look at the rockets, robots and gizmos on display. He checked out a buoy alert system that notifies people of rip currents, admired an egg-propelling rocket and tested out a bicycle that powers a water-filtration system.

As he got on the bike, Obama joked, gesturing to the media.

"Only because these guys really want this," Obama quipped.

He then spent several minutes cycling in place while the two students explained how their invention worked.

"We celebrate our great football players … and we celebrate outstanding musicians, and that's all appropriate," Obama later said. "But we've got to make sure that we're also celebrating, every single day in our schools, in our classrooms and in our country, the outstanding contributions that scientists and engineers and mathematicians and engineers are providing to us every single day."

"We want you to know that you've got a whole country behind you as you pursue your dreams," he said. "And your success is going to be our success, as well. So, way to go."