MINEOLA, New York (AP) ― Alan Alda, the actor-turned-part-time professor, has a new question for scientists to consider: How do you explain color to an 11-year-old?

The television and film star best known for his role in the 1970s sitcom “MASH” is posing the question as part of the third annual “Flame Challenge.”

Alda helped organize the international contest as part of his work at the Stony Brook University Center for Communicating Science.

The university on eastern Long Island named the center in Alda’s honor earlier this year; its goal is to get scientists in various disciplines to explain complex concepts in the simplest of ways.

This year’s question was selected by Alda after receiving about 800 suggested questions from children. He explained that many questions focused on issues about light and color, including the childhood classic: “Why is the sky blue?”

“I’m in awe of the scientists who can bring clarity to these questions and I’m in awe of the kids who keep the scientists on their toes,” Alda said.

Alda, a New York native who has had a lifelong interest in science, started the contest in 2011 by asking scientists: What is a flame?

He followed that up last year with: What is time?

Now comes color.

“We want scientists to think about how they can answer the question from their own field ― from biology to physics to anthropology or psychology,” said Elizabeth Bass, director of the Alda Center.