MEXICO CITY — The clock is ticking down to Dec. 21, the supposed end of the Mayan calendar, and from China to California to Mexico, thousands are getting ready for what they think is going to be a fateful day.

The Maya didn’t say much about what would happen next, after a 5,125-year cycle known as the Long Count comes to an end. So into that void have rushed occult writers, bloggers and New Age visionaries foreseeing all manner of monumental change, from doomsday to a new age of enlightenment.

The 2009 disaster flick “2012” helped spark doomsday rumors, with its visions of Los Angeles crashing into the sea and mammoth tsunami waves swallowing the Himalayas. Foreboding TV documentaries and alarmist websites followed, sparking panic in corners of the globe thousands of miles from the Mayan homeland of southern Mexico and Central America.

As the big day approaches, governments and scientists alike are mobilizing to avoid actual tragedy. Even the U.S. space agency NASA intervened earlier this month, posting a nearly hour-long YouTube video debunking apocalyptic points, one by one.

The Internet has helped feed the frenzy, spreading rumors that a mountain in the French Pyrenees is hiding an alien spaceship that will be the sole escape from the destruction.

French authorities are blocking access to Bugarach peak from Dec. 19-23 except for the village’s 200 residents “who want to live in peace,” the local prefect said in a news release.

“I think this tells us more about ourselves, particularly in the Western world, than it does about the ancient Maya,” said Geoffrey Braswell, an associate professor of anthropology and leading Maya scholar at the University of California, San Diego. “The idea that the world will end soon is a very strong belief in Western cultures. ... The Maya, we don’t really know if they believed the world would ever end.”

As the clock ticks down, scenarios have mounted about how the end will come.

Some believe a rogue planet called Nibiru will emerge from its hiding place behind the sun and smash into the Earth. Others say a super black hole at the center of the universe will suck in our planet and smash it to pieces. At least two men in China are predicting a world-ending flood: They’re both building arks.

Lu Zhenghai, 44, has spent his life savings, some $160,000, building the 70-foot-by-50-foot vessel powered by three diesel engines, according to state media.

“I am afraid that when the end of the world comes, the flood will submerge my house,” he was quoted as saying.

China’s most innovative ark builder, however, may be Yang Zongfu, 32, a businessman in eastern China.

His vessel, Atlantis, a three-ton yellow steel ball 13 feet in diameter, is designed to survive a volcano, tsunami, earthquake or nuclear meltdown, according to the state-run Liao Wang magazine.

Jose Manrique Esquivel, a descendent of the Maya, said his community in Mexico’s Yucatan peninsula sees the date as a celebration of their survival despite centuries of genocide and oppression. He blamed profiteers looking to scam the gullible for stoking doomsday fears.

“For us, this Dec. 21 is the end of a great era and also the beginning of a new era. We renew our beliefs. We renew a host of things that surround us,” Esquivel said.

The mystery isn’t only inspiring dread: Some are whipping out their yoga tights and meditation cushions and joining a global counter-movement promoting the date as the start of a new era of hope.

Thousands of New Age adherents are expected to fill ancient sites across Mexico in the days leading up to Dec. 21, while their spiritual brethren party in hotspots as diverse as Culver City, Calif., and Byron Bay, Australia.

One of the biggest movements is Birth 2012, which is using the Mayan date to launch what it hopes will be a global spiritual reset. Some 40 events around the world will mark the change.

“We’ve activated this campaign for three days of love,” movement co-founder Stephen Dinan said.

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