Carnegie Science Center employee James Hughes took the microphone over to Alex D'Anunzio yesterday and asked him if the pie-eating contest was the most fun he'd ever had in his life.

The answer was a sloppy and enthusiastic "Uh-huh!"

Of course, when you're only 4 years old, you haven't had that many experiences. And making a mess is what you do for a living.

More than 3,500 people -- most of them youngsters -- turned out yesterday for "MessFest," the science center's third annual day of mixing education with fun in a way that gets all over you.

"This is the activity for kids on New Year's Day," said Mike Marcus, the center's assistant director for marketing and community affairs. "We break out all of our messiest hands-on activities."

Kids got to make paper and sidewalk chalk. They decorated cookies and created Martian soil. They turned plain white paper plates into colorful fish.

Upstairs on the third floor was a kiddie pool full of oobleck, a combination of corn starch and water that violates Newtonian laws regarding solids and fluids. If you apply pressure, it takes a solid form. If you let it rest, it oozes into ooze.

Autumn Walker, 7, of West Lake, Ohio, made a deep study of the oobleck. (Her mother brought her a change of clothes, so all bets were off.)

"It's really cool," Autumn said, her pants splattered with pasty muck. "The more water you put into it, the more liquidy it gets."

Another popular experiment was the egg drop, where youngsters use Styrofoam, bubble wrap, newspaper, tissue and other items to determine how much padding it takes to protect an egg dropped from the third floor to the second. (Hint: The best way to protect it is to incorporate a parachute into the design, but then you don't get to see the egg go splat.)

The events, like most things at the science center, appeal to a wide range of ages, but making a mess is pretty much the domain of those under 10.

"This is their first step into learning science," Mr. Marcus said. "Kids get great education, but it's a lot of fun. It's a tremendous hit, and we're already making plans for next year."

At one table, a simple Alka-Seltzer tablet and a little water were used to turn a tiny plastic film container into a fizzy noisemaker/projectile.

"Pretty much all of these things are super easy to do," said center employee Tyller Little. "Kids can do them at home or in a classroom."

Robbie Rothmeyer, 9, of Millvale, couldn't wait to get his face into the plateful of vanilla pudding and whipped cream that constituted a "pie" in the no-holds-barred, no-hands-allowed pie-eating contest.

"I'm really good at eating," he said as he sized up the pint-sized competition. "I mostly like chocolate pudding, but I'll eat vanilla."

Mr. Hughes, serving as starter for the contest, explained the simple rules.

"Now, we want you to take all the manners that you've learned and throw them away," he said.

Napkins were not distributed until the parents had taken photos of the contestants.