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)

A visiitor bungee jumps during an outdoor festival to celebrate German Unity Day on the 21st anniversary of German reunification on October 3, 2011 in Berlin, Germany. German Unity Day is a national holiday and marks the day West Germany and East Germany were reunited in 1990 following the collapse of the Iron Curtain. (Photo by Adam Berry/Getty Images)

(L-R) Talents Yasmina Hunzinger, Lisa Martine Weller, Kim Sanders and Sharron Levy pose during a photocall to the TV show “The Voice of Germany” on January 3, 2012 in Berlin, Germany. (Photo by Andreas Rentz/Getty Images)

Young dancers perform at a preview show for the Chinese Lantern Festival which falls on February 6 and traditionally marks the end of the Lunar New Year celebrations on February 3, 2012 in Beijing, China.The Lantern Festival also known as the Yuanxiao Festival or Shangyuan Festival in China.(Photo by Lintao Zhang/Getty Images)

A girl uses her mobile phone during the evening at the National Park in Khartoum, Sudan, April 24, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A reveler gets ready to perform at a carnival parade in Havana, Cuba August 7, 2015. (Photo by Alexandre Meneghini/Reuters)

An Afghan man works at a traditional yarn factory in Heart province, Afghanistan July 28, 2015. (Photo by Mohammad Shoib/Reuters)