An iCub robot built by the Italian Institute of Technology tracks a ball in the Robotville exhibition at the Science Museum on November 29, 2011 in London, England. The Science Museum's Robotville exhibition showcases 20 unique and cutting-edge robots from European research laboratories, it is free to enter and runs from December 1–4, 2011. (Photo by Oli Scarff/Getty Images)

A girl attends Friday prayers in front of an army tank in Tahrir Square in Cairo February 18, 2011. Five years ago thousands of protesters took to the streets demanding the end of the 30-year reign of President Mubarak as Egypt became the second country to join the Arab Spring. After weeks of clashes, strikes and protests across Egypt, Mubarak resigned on February 11, 2011. (Photo by Suhaib Salem/Reuters)

A mongoose growls at a startled lion on September 10, 2011 in Maasai Mara, Kenya. Four lions were left with their tails between their legs when a mongoose bravely took on the predators. Despite being under two feet tall, the aggressive mongoose growled at the felines and even bit one on the nose. The shocking fight, which was photographed in 2011 but has just been released, began in the Masaai Mara National Park, Kenya, when photographer Jerome Guillaumot came across four young lions surrounding the terrified marsh mongoose. The lions chased the mongoose into a hole in the ground but the small animal reemerged to fight the predators once again before running for cover. (Photo by Jerome Guillaumot/Barcroft Media)

Justin Beiber unveils his waxwork at Madame Tussauds on March 15, 2011 in London, England.

A rebel fighter supporter shoots an AK-47 rifle as she reacts to the news of the withdrawal of Libyan leader Muammar Gaddafi's forces from Benghazi March 19, 2011. The conflict was sparked by clashes in Benghazi and escalated into a rebellion that spread across the country. Gaddafi was captured and killed on October 20, 2011. Libya is currently caught up in a conflict between two rival factions who once battled together against the late Libyan leader. (Photo by Goran Tomasevic/Reuters)

Women Wrestlers, Bolivia. Lucha libre (Bolivian wrestling) is one of the most popular sports in the country. Women wrestlers are known as cholitas and have in the last ten years become popular in the sport. Here, Carmen Rosa and Yulia la Pacena perform in a benefit show to raise money for the bathrooms of a school in La Paz, Bolivia, 26 June 2011. (Photo by Daniele Tamagni)

Assistant Manager Jayesh Vaghela brushes a vintage silk top hat at Lock & Co. Hatters on March 22, 2011 in London, England. Founded in St. James's in 1676, when Charles II was on the throne, this family owned business has provided hats for Royalty and the gentry for over 300 years. Staff report that sales of formal hats are booming ahead of the wedding of Prince William and Kate Middleton in Westminster Abbey on April 29, 2011.

“Takeru Kobayashi (born March 15, 1978) is a Japanese competitive eater. He held the world record for hot dog eating for nearly six years, and holds several other eating records, including four Guinness Records for hot dogs, meatballs, hamburgers, and pasta”. – Wikipedia

Photo: Takeru Kobayashi challeges 2011 Nathan's Famous Hot Dog Eating Competition contestants via satellite at 230 Fifth Avenue on July 4, 2011 in New York City. (Photo by Cindy Ord/Getty Images)