In search of Genghis Khan's tomb

Albert Lin is hunting for Genghis Khan.

Legend has it that Khan, the ruthless conqueror who was the first emperor of the Mongol Empire, was buried in an unmarked tomb in northern Mongolia about 800 years ago.

But finding said tomb is a task that has eluded scientists for years. Mongolia encompasses more than 600,000 square miles of largely uncharted, rural territory, which makes Lin's mission extremely challenging. replicas de relojes

Luckily, the explorer and research scientist at the University of California at San Diego has more than 7,000 people around the world helping with his mission, called the Valley of the Khans Project. The idea is to find the tombs of Genghis Khan and his descendants, and other ancient Mongolian artifacts.

Lin's army of helpers are amateurs, working from the comfort of their home computers.

Through a website called Field Expedition Mongolia, which Lin and his colleagues developed jointly with National Geographic, volunteers are helping sift through 85,000 high-resolution satellite images of Mongolia.

Every time volunteers log in to the site, they are shown some of these images. An online tutorial instructs them on how to look for particular objects and tag them as "roads," "rivers," "modern structures" or "ancient structures." They can zoom in and out and scroll in all directions.

They are also told to simply tag places as "other" if they see something peculiar. This is the sort of vague judgment that humans can perform but that computers cannot, Lin said.

"What a computer can't do is look for 'weird things,' but when you ask a human brain, you don't have to tell it what 'weird' is; we know," Lin said.

Those weird things could be important archaeological finds, he said.

Last summer, Lin and his colleagues were in Mongolia inspecting the places that had been tagged by the online volunteers. Anytime there was a cluster of tags marked as "ancient structure" or "other," they would note the latitudinal and longitudinal coordinates, grab their GPS devices and scope it out.

"We'd literally jump on horses or get in a helicopter and go check it out," said Lin. "Every tag was weighted on how many other people tagged the same thing."

Projects like this one mark a new twist in "citizen science," where new technology, when used effectively by large groups of people, can help speed up scientific developments, reduce costs and increase efficiency.

Sometimes online volunteers led the explorers to disappointing finds, such as a herd of sheep on a satellite photo that looked like an ancient structure. But there were also some remarkable ones, such as the discovery of 3,000-year-old Bronze Age tombs, remnants of large cities and ancient monoliths hidden in the region's vast, grassy steppe.

"These are hard to find on horseback, but from space and in the images, you can make out these shapes," Lin said.

Though professional scientists have collaborated with amateurs for decades, social networking and the Internet are making it more fruitful than ever.

"We found that we could make something that was engaging enough to inspire people to participate without having to pay them," says Lin. "This is the part of citizen science that is most interesting to me: How can we motivate people to dedicate their time?"

How? By making it fun, Lin said.

Lin began thinking about creating an online expedition that tied into his real one about five years ago, when Amazon.com's Mechanical Turk made its debut.

An online crowd-sourcing marketplace, Mechanical Turk allows requesters with small tasks to pay people for their time. Anyone with an Amazon account can participate, and the tasks are usually quite simple, such as "pick out the images with tattoos from this set," or "verify the existence of these business Web sites." Some tasks pay just pennies, per task or verification, while others pay more.

Lin believed that he could get more traction by creating a site that offered a fun experience rather than a paid one. "People are so excited to learn about Mongolian archaeology," he said. "They start to learn stuff about what they're doing and feel more connected to what's going on in that part of the world."

Every volunteer who logs on to the Valley of the Khans project site, developed with a design company called Digiteria, gets to feel like an explorer, digging through images and playing what feels like a game but performing work that has much more significant ramifications.

"It connects you more on a personal level than going to a museum," said Allison Shefcyk, a 24-year-old in Connecticut who tagged more than 50,000 images from her home computer. "I ended up picking up some books on Genghis Khan and Mongol culture, and even though I never set foot there, it all provided a deeply moving experience."