A man admires a sculpture in the series entitled 'Circle of Animals/Zodiac Heads' by Chinese artist Ai Weiwei in the courtyard of Somerset House on May 11, 2011 in London, England. The installation comprises of 12 bronze heads of animals which feature in the Chinese zodiac. The artist Ai Weiwei, who is outspoken in his criticism of the Chinese administration, was detained by authorities in Beijing on April 3, 2011 and his whereabouts remain unknown.

Japan's electronics equipment maker MuRata Manufacturing Co., Ltd's showcased their bicycle-riding robot “MuRata Boy” during the CEATEC Japan 2006 exhibition on October 3, 2006 in Chiba, Japan. The “MuRata Boy” robot can ride up a 25-degree slope, stop without losing its balance and make an S-curve without falling. (Photo by Koichi Kamoshida/Getty Images)

Shortlisted images in the running to be crowned Photobox Instagram photograph of the year range from furry friends to the Holi festival to the meaning of love. Judges, including the Guardian’s former picture editor Eamonn McCabe, have whittled down 180,000 submissions to unearth a shortlist that celebrates the best of social media. Winners will be announced October 3, 2018. Here: Najac, France. Travel shortlist. (Photo by Aaron Jenkin/@aaronjenkin)

Afghan National Army (ANA) soldiers sit waiting to return their weapons after a day of traning at the Kabul Military Training Center (KMTC) October 3, 2010 in Kabul, Afghanistan. There are between 5,000 to 7,000 troops on the training facility in eight-week cycles trained by the coalition forces to ultimately take over the role of military operations in the country. (Photo by Paula Bronstein/Getty Images)

A model showcases designs by Isola by Megan Gale on the catwalk at the David Jones Spring/Summer 2011 season launch at the Royal Hall of Industries, Moore Park on August 3, 2011 in Sydney, Australia. (Photo by Lisa Maree Williams/Getty Images)

Workers at the World's Finest Chocolate company weigh what they hope will be a world record chocolate bar September 13, 2011 in Chicago, Illinois. The candy bar, weighing 12,190 pounds, standing nearly 3 feet high and measuring 21 feet long beat the previous record chocolate bar by more than a ton. (Photo by Scott Olson/Getty Images)

Actresses Zelda Williams and Kelly Monaco attend Nintendo's celebration of the launch of Super Mario 3D Land at Siren Studios on November 3, 2011 in Hollywood, California. (Photo by Jason Merritt/Getty Images for Nintendo)

Madison Sager (L), Jocelyn Sager and Susan Ihry (C) make their way through the West Acres Mall JCPenney store after 3 a.m. on November 25, 2011 in Fargo, North Dakota. The trio began shopping at 10 p.m. the night before at Walmart. (Photo by Chris Franz/Getty Images)