You need science to create a cartoon

Tomas Reimers, a sixth-grader in Belmont, Mass., wants to set the record straight: "A lot of parents think cartoons are mindless," he says. "They're not. I find them so interesting – how they're made. I watch a lot of them."

He was in good company at the Museum of Science in Boston, where, through May 16, a children's exhibition explores the science, history, and fun of animation.

"Animation" occupies nearly 6,000 square feet and features about a dozen interactive displays that provide kids and adults with a behind-the-scenes look at how cartoons are created. It also looks at how other animated effects, such as those seen on TV and in the movies, are made.

The exhibition adds historical context to moving images – showing how animation has evolved from simple drawings to computer-generated three-dimensional images.

But you don't have to be a budding cartoonist or even a "techie" to enjoy these exhibits, says first-grader Caitlin Fowler of Belmont. "I'm just here to have fun," she says as she spins a praxinoscope with the help of her younger brother, Kyle.

The praxinoscope (pronounced praks-EN-o-scope) is an optical device that was invented in France in 1877.It resembles a Lazy Susan that's been covered with small mirrors on the outside. When spun, the mirrors bring stationary images to life by making them look as if they're moving.

The faster the praxinoscope is spun, the more "seamless" or smooth the image reflected in it appears to the viewer. And there's some real science behind that.

The effect, which scientists call "apparent motion," is created when slightly different images flicker quickly in front of the eye. Although there's a break between each image – in the case of the praxinoscope, the small gap between the mirrors – the images merge together. There's no break at all.

In 1889, the praxinoscope was replaced by the photographic film projector, a machine that's still used today in many movie theaters. Yet the scientific principles are the same.

At the Animation Studio display, kids learn that it takes about 30 still drawings or photographic images to create just one second of animation.

Tomas, the sixth-grader who is a big fan of animated cartoons and movies, was impressed. "It doesn't surprise me that a two-hour movie can take two years to make," he says, after learning about the processes involved. "It takes time to put it all together."

His enthusiasm about the science of animation is exactly what museum officials hope the exhibition will foster in kids of all ages.

"Art, math, and physics are all the components of animation," says Sofiya Cabalquinto, who works at the museum.

When, for instance, animators illustrate a bouncing ball, they must understand its succession of movements before they can draw it. "Then," she says, "animators often will exaggerate the movement for comedic value."

Sound usually is added to animated features in postproduction (after the drawing or photography is completed). This is done by "Foley artists." They are named after Jack Foley, a sound technician in the early 1900s at Universal Studios in California.

Foley effects can include sounds such as footsteps, clothes rustling, dishesclinking, paper folding, doors opening or slamming, and glass breaking.

Frequently, the objects used to make a sound in an animated feature are unrelated to the sound. For instance, the sound of snow crunching underfoot may really be cornstarch in a leather pouch. And thunder is nothing more that a large sheet of plastic being bent or shaken.

At the exhibition, kids can try their hand at being a Foley artist by recording their own sound effects to a silent cartoon shown on a large TV screen.

But animation is not all about cartoons and movies. "Some scientists even use animation to map out areas of Mars that no one has seen," says Miss Cabalquinto. They base their images on information that's available to them from the parts of Mars that they have seen.

At the other end of the room, Tomas; his younger brother, Pablo; and a friend, Chris, are all laughing and hopping about on a special floor as cameras mounted high above them record their every move at three-second intervals.

They're on what's called an "animation grid." It's a tiled floor that resembles a giant checkerboard. Animators use grids such as this to organize the movements of objects they're animating.

The grids enable them to break up space into smaller, equal sections, making it easier to create more natural-looking movements.

Many Claymation and stop-motion features – such as the television show featuring Gumby and his horse, Pokey – are created with grids. But they're also used to compile information in other fields, such as mapmaking and mathematics.

After spending nearly two hours with the various exhibits, Tomas was ready to head off to another section of the museum. But he says he has a new appreciation for the science of cartoons.

• From June 9 to Sept. 3, the exhibit can be seen at the Center of Science and Industry in Columbus, Ohio.