Capturing movie magic; Bill Nye practices his science on Mt. Wilson; Mr. Freeze is in the batcave

The secrets of movie-making, from special effects to stunts, are revealed to young viewers on Mega Movie Magic (Discovery, Sunday at 10 a.m.). Kids go behind the scenes to learn how John Goodman avoids stepping on the 4-inch-tall people in “The Borrowers,” and how a city (Los Angeles) could be destroyed in an instant in “Volcano.” The latter segment reveals how scale models of city streets, skyscrapers and rivers of lava were made to create great destruction effects. For ages 7 to 15.

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Being a new mom can be difficult even with one bundle of joy, but imagine dealing with two, three or more babies born together. Supertwins: Triplets, Quads and More (Learning Channel, Sunday at 6 p.m.) looks at some women grappling with this task and offers advice in raising these children. A particularly sobering fact: Parents of triplets use nearly 7,000 diapers a year. For ages nine and up.

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Disney’s animated classic “The Lion King” gets an encore on network television (ABC, Sunday at 7 p.m.). The film tells of the love between Simba, a heroic young lion who is struggling to find his place in nature’s “circle of life,” and his father, Mufasa, the lion ruler. James Earl Jones is the voice of Mufasa. For the family.

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Batgirl is kidnapped by Mr. Freeze on Batman & Mr. Freeze: Subzero, an episode of “Batman” (WB, Saturday at 8 a.m.). Batman and Robin blast into animated action, using high-tech methods to rescue her from the cold-blooded bad guy. For ages 7 to 11.

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“Bill Nye, the Science Guy” goes out-of-this-world on an episode entitled “Outer Space” (KCAL, Saturday at 9 a.m.). Actually, he visits Mt. Wilson observatory here to help illustrate how long it takes light to travel through the galaxy. He also he examines the mysterious world of insects. For ages 8 to 14.