ORONO, Maine — The ancient Maya — who developed a written language and advanced calendars more than 11 centuries ago — created one calendar that has become a pop-culture phenomenon: Conspiracy theorists believe it predicts the end of the world on Dec. 21, 2012.

Some of those who believe the end of the world is near are featured in a presentation, “2012: Prophecies of the Maya,” which is showing Friday nights until Dec. 14 at the University of Maine’s Maynard F. Jordan Planetarium.

“I was skeptical, and the more I learned the more I realized it’s completely ridiculous,” planetarium director Alan Davenport said recently of the doomsday predictions. “There is no foundation in any form of real science behind this.”

Even so, there are believers out there who are taking no chances and are preparing for the worst, said Ralph McLeod, owner of Buyers Guns in Holden. The survivalists are called “doomsday preppers.”

“I personally know people who believe every conspiracy theory that comes down the pike,” McLeod said, surrounded by guns, ammunition, swords and survival gear. “Awhile back they were talking about the rapture. Remember the Y2K hype?”

The Mayan empire, which reached its height between 300 A.D. and 900 A.D. in Central America, created an elaborate Long Count calendar that breaks down time into several cycles based on the movement of the moon and stars in the night sky, as well as other factors.

The 13th period, or Baktun, which is roughly 394 Mayan years, ends on Dec. 21, 2012.

“People see that and they go, ‘Well, that must mean there are no other dates because it’s the end of the world,’” McLeod said. “It’s not really the end of the world, but everybody likes a theory — a conspiracy — or anything that is high drama, and there are people who will sign onto that regardless of what the real facts are.”

There are a number of websites and blogs dedicated to Mayan history, doomsday theories and survival, some of which use the acronym TEOTWAWKI, which means “The End of the World as we Know it.”

Nearly 22 percent of people surveyed in the U.S. and 15 percent worldwide believe the world will end during their lifetime, according to an international poll of 16,262 people in more than 20 countries conducted for Reuters and released in May.

People with lower levels of education or household incomes, and those under age 35, were more likely to believe in an apocalypse during their lifetime or in 2012, and about 10 percent said the end of the Mayan calendar could mean an armageddon will begin in December, according to the poll data, compiled for Reuters by Ipsos Global Public Affairs.

Young Mainers, including friends of his daughter, are believers, said Colby College associate professor Ben Fallaw, who has taught Latin American studies at the Waterville college since 2000.

People like to read stories and watch movies and television shows about the end of the world, he said, citing the movie “2012” and various History Channel programs about the Maya as examples.

“For whatever reason, people enjoy that,” Fallaw said. “The Mayans had a very advanced knowledge of languages, calendars and astronomy. They were highly accomplished.”

Unanswered questions about the “very advanced” Maya — who abandoned entire cities centuries ago that have since been engulfed by jungle vines — make their tale even more intriguing, he said.

“The Mayans are very mysterious — or perceived as mysterious — and everybody loves a good story,” Fallaw said.

When he gave a presentation about the Maya in the spring, he discussed how Mexico, Guatemala and other Central American countries are celebrating the calendar’s end as the start of a new Baktun, and are using it as a marketing tool to entice tourists.

He also made room for far-fetched stories that the ancient native people were assisted by beings from another planet.

“It’s remarkable how much is out there” on the Internet, Fallaw said. “I’m afraid some people — even those who read all this — will still believe.”

Fallaw, who has been to Mayan cities in the Mexican state of Yucatan, said much of the hype around the Long Count calendar is focused on one broken stone text found in the 1960s at the Tortuguero archaeological site in Tabasco, Mexico.

“It’s damaged. Imagine reading a newspaper and half of it was missing,” Fallow said.

Some say the damaged text described the return of a Mayan god, while alien theorists believe an extraterrestrial will return, at the end of the 13th Baktun.

NASA has its own theories about how the Mayan apocalypse story started, and posted a question-and-answer section titled “Beyond 2012: Why the World Won’t End” on its website.

The alignment of planets, the reversal of the Earth’s magnetic field, solar storms, and “the secret planet of Nibiru” are all debunked by the NASA website.

“The story started with claims that Nibiru, a supposed planet discovered by the Sumerians, is headed toward Earth,” the site states. “This catastrophe was initially predicted for May 2003, but when nothing happened the doomsday date was moved forward to December 2012 and linked to the end of one of the cycles in the ancient Mayan calendar at the winter solstice in 2012 — hence the predicted doomsday date of Dec. 21, 2012.”

Bangor middle schooler Nick Canarr, 12, said recently that he went to the NASA website a couple of months ago.

“I Googled it one day and NASA said the world would not end on Dec. 21, but they did say havoc may come,” he said. “I thought it was going to end. I was wondering if it was true.”

Bangor resident Eve Preston said Friday that her granddaughter believes the world is coming to an end, so to “humor” her the family will not go Christmas shopping until Dec. 22.

“She’s 17 and she’s sure we’re not going to make it,” Preston said. “I think probably the calendar was meant to roll over and I’m not worried.”

Her granddaughter may be a believer but still has started a Christmas list, Preston said with a smile.

Ellsworth resident Aseidas Blauvelt, who works in downtown Bangor, said he’s looking forward to Dec. 21.

“I’ve been invited to a few Mayan parties,” he said Friday while out walking his dog. “I’m not worried. I’m looking forward to 2013.”

Paddy Murphy’s is one local business that is hosting a party on Dec. 21, with two live bands, manager Andy Day said.

The Jordan Planetarium’s Nov. 16 Mayan presentation drew about a dozen people who sat under the planetarium’s dome watching computer animations and video interviews to learn about the rituals of the Maya — including human sacrifices — and how the culture’s Long Count interlocking circular calendar worked.

When asked why they attended the show, one person in the dark said, “Just curious.” Another voice said, “Debunk some myths.”

Chicken Little said, “The sky is falling,” and everyone believed it. The folktale makes fun of the mass hysteria created by the chicken’s actions, and Donald Rice, a University of Maine student leading the lecture, used the story to describe what is happening with the Mayan calendar.

“I’m here to be a scientific voice for you,” he said. “December 21 will be nothing but a [winter] solstice like every year.”

Others in the planetarium group agreed the calendar is just that, a calendar.

“I don’t think it’s the end of the world — it’s the beginning of a new era,” said Sherri Kinney of Gorham, who drove up to UMaine with her husband, Don, just for the presentation.

“The long calendar is not the only calendar they had,” Don Kinney said of the Maya.

His wife added she first became interested in the Maya six years ago.

“I think this was debunked awhile ago … with a different calendar,” Paul Villeneuve, an associate professor of electrical engineering technology at UMaine, said after the Jordan Planetarium presentation. He was referring to a story last spring about archaeologists digging at a Maya site in Guatemala who discovered Mayan calendars. The story dismissed notions that the ancient sky-gazers prophesied the end of the world.

“These deep-time calendars can be used to count thousands of years into the past and future, countering pop-culture and New Age ideas that Mayan calendars ended on Dec. 21, 2012 [or Dec. 23, depending on who’s counting], thereby predicting the end of the world,” says the story in The Washington Post.

“Like the year 2000, this is a cause for celebration, not disaster,” Rice said.

“We’re all going to wake up and say, ‘Huh.’ Then we’ll go on and enjoy the holidays,” Don Kinney said.