LOS ANGELES — Ray Bradbury anticipated iPods, interactive television, electronic surveillance and live, sensational media events, including televised police pursuits — and not necessarily as good things.

The science fiction-fantasy master spent his life conjuring such visions from his childhood dreams and Cold War fears, spinning tales of telepathic Martians, lovesick sea monsters and, in uncanny detail, the high-tech, book-burning future of "Fahrenheit 451."

All of them, in short stories, in the movie theater and on the television screen, would fire the imaginations of generations of children and adults across the world.

Mr. Bradbury, who died Tuesday night at age 91, was slowed in recent years by a stroke that meant he had to use a wheelchair. But he remained active over the years, turning out new novels, plays, screenplays and a volume of poetry.

He wrote recently in The New Yorker about discovering science fiction when he was 7 or 8 years old. "It was one frenzy after one elation after one enthusiasm after one hysteria after another," he wrote. "I was always yelling and running somewhere, because I was afraid life was going to be over that very afternoon."

He wrote every day in the basement office of his home in the Cheviot Hills neighborhood of Los Angeles.

It was a career he often said was inspired by a chance meeting in 1932 with a carnival magician called Mr. Electrico who, at the end of his performance, reached out to the captivated 12-year-old, tapped him with his sword and said, "Live forever!"

"I decided that was the greatest idea I had ever heard," Mr. Bradbury said later. "I started writing every day. I never stopped."

His writings ranged from horror and mystery to humor and sympathetic stories about the Irish, blacks and Mexican-Americans. Mr. Bradbury also scripted John Huston's 1956 film version of "Moby Dick" and wrote for "The Twilight Zone" and other television programs, including "The Ray Bradbury Theater," for which he adapted dozens of his works.

"He was my muse for the better part of my sci-fi career," director Steven Spielberg said in a statement. "He lives on through his legion of fans. In the world of science fiction and fantasy and imagination, he is immortal."

Mr. Bradbury broke through in 1950 with "The Martian Chronicles," a series of intertwined stories that satirized capitalism, racism and superpower tensions as it portrayed Earth colonizers destroying an idyllic Martian civilization.

That book, "Fahrenheit 451" and others continue to be taught at high schools and universities around the country.

"The Martian Chronicles" was a Cold War morality tale in which imagined lives on other planets serve as commentary on human behavior on Earth. "The Martian Chronicles" has been published in more than 30 languages, was made into a TV miniseries and inspired a computer game.

Inspired by the Cold War, the rise of television and the author's passion for libraries, "Fahrenheit 451" was an apocalyptic narrative of nuclear war abroad and empty pleasure at home, with firefighters assigned to burn books instead of putting blazes out (451 degrees Fahrenheit, Mr. Bradbury had been told, was the temperature at which texts went up in flames).

Mr. Bradbury's novel anticipated today's world of iPods and electronic surveillance. François Truffaut directed a 1966 movie version.

Although involved in many futuristic projects, Mr. Bradbury was deeply attached to the past. He refused to drive a car or fly, telling the AP that witnessing a fatal traffic accident as a child left behind a permanent fear of automobiles.

"I'm not afraid of machines," he told Writer's Digest in 1976. "I don't think the robots are taking over. I think the men who play with toys have taken over. And if we don't take the toys out of their hands, we're fools."

Mr. Bradbury's literary style was honed in pulp magazines and influenced by Ernest Hemingway and Thomas Wolfe, and he became the rare science-fiction writer treated seriously by the literary world. In 2007, he received a special Pulitzer Prize citation.

His fame even extended to the moon, where Apollo astronauts named a crater "Dandelion Crater," in honor of "Dandelion Wine," his beloved coming-of-age novel, and an asteroid was named 9766 Bradbury.

A digital copy of Mr. Bradbury's "The Martian Chronicles" along with works by other science-fiction legends was flown into space in 2007 by NASA's Phoenix spacecraft, which touched down on the Martian arctic plains.

He was born Ray Douglas Bradbury on Aug. 22, 1920, in Waukegan, Ill. His father, Leonard, was a descendant of Mary Bradbury, who was tried for witchcraft at Salem, Mass. The author's mother, Esther, read him the "Wizard of Oz." His Aunt Neva introduced him to Edgar Allan Poe and gave him a love of autumn, with its pumpkin picking and Halloween costumes.

Mr. Bradbury's family moved to Los Angeles in 1934. He became a movie buff and a voracious reader. "I never went to college, so I went to the library," he explained.

He sold his first story in 1941. He submitted work to pulp magazines until he was finally accepted by such upscale publications as The New Yorker. Mr. Bradbury's first book, a short story collection called "Dark Carnival," was published in 1947.

He was so poor during those years that he didn't have an office or even a telephone. "When the phone rang in the gas station right across the alley from our house, I'd run to answer it," he said.

In 2009, at a lecture celebrating the anniversary of a small library in Southern California's San Gabriel Valley, Mr. Bradbury exhorted his listeners to live their lives as he said he had lived his: "Do what you love and love what you do."

"If someone tells you to do something for money, tell them to go to hell," he shouted to raucous applause.

Mr. Bradbury is survived by his four daughters, Susan Nixon, Ramona Ostergren, Bettina Karapetian and Alexandra Bradbury. Marguerite Bradbury, his wife of 57 years, died in 2003.