Attention, scientists: 11-year-olds everywhere would like to know, "What is sleep?"

The question may seem complex, but actor Alan Alda, renowned for his roles on the hit TV shows "M*A*S*H" and "The West Wing," is asking researchers around the world to make the answer simple and understandable to the children, who will judge the entries.

"I think that 11-year-old kids are probably all reaching that point in their lives when they want answers to complicated questions, but they want them with clarity," said Alda, a visiting professor in the school of journalism at Stony Brook University, in New York. "They don't want to be talked down to. It's a very interesting time."

This is the fourth consecutive year that the Alan Alda Center for Communicating Science, at Stony Brook University, has called on researchers to demystify tricky scientific concepts in what has been dubbed the "Flame Challenge" (since the inaugural challenge in 2011 sought an answer to the question "What is a flame?"). Alda started the contest because of a fruitless answer he got to the flame question from a science teacher years ago.

"In a way, it was a lucky accident," Alda told Live Science. "I wondered what a flame was when I was 11, and I asked a teacher to explain it to me. All she said was, 'It's oxidation.' I never got a good explanation. I didn't know what oxidation was. Oxidation was just another word for me."

In 2012, Alda's next challenge asked scientists to describe time, and in 2013, the actor challenged researchers to  clarify the concept of color, relying on nearly 27,000 students to judge the entries.

This year's question, "What is sleep?" will help children learn about how they spend about one-third of their lives. Alda thinks he may also have something to learn from the submissions. 

"That's what I'm hoping — that if 11-year-olds can get it, then I'll get it, too," Alda said.

The Flame Challenge invites any scientist — from graduate students to the leaders of labs — to enter the contest by writing an explanation, filming a video or creating a graphic. The deadline for entry is Feb. 13, 2015. A panel of scientists will screen the entries for scientific accuracy before 11-year-olds across the U.S. and other countries judge the submissions.

Two winners, one for a written explanation and the other for a video or graphic entry, will each be awarded a $1,000 cash prize. The winners will also be flown to New York City, where they will meet Alda and be honored at the World Science Festival in May 2015.

Researchers from any scientific discipline can enter the contest, and more information can be found on theFlame Challenge website.

"I really do hope that scientists from all different kinds of fields will give it a try," Alda said. "Somebody said once, 'How do I know what will be appealing to an 11-year-old?' We said, 'Why don't you talk to one?' Because that's the essence of communicating. Keeping in mind who you're talking to."

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