A wrestler from the Nuba Mountains tribe is seen during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. The International Day of the World's Indigenous Peoples is observed on August 9 annually. (Photo by Mohamed Nureldin Abdallah/Reuters)

A Thorneycroft motor van as used during World War I. (Photo by Topical Press Agency/Getty Images). August 1914

New York City Mayor Michael Bloomberg gets on a custom made World Trade Center inspired motorcycle in front of the 9/11 Memorial Preview Site on October 5, 2011 in New York City. The motorcycle was designed by Paul Teutul Jr. of the television show “American Chopper” and was built to commemorate the rebuilding of the World Trade Center Site. Another motorcycle, nearly identical to the one unveiled, will also be built by Paul Jr. and raffled to raise money for the 9/11 Memorial. (Photo by Spencer Platt/Getty Images)

“RoboCup is an international robotics competition founded in 1997. The aim is to develop autonomous soccer robots with the intention of promoting research and education in the field of artificial intelligence. The name RoboCup is a contraction of the competition's full name, «Robot Soccer World Cup», but there are many other stages of the competition such as «Search and Rescue» and «Robot Dancing»”. – Wikipedia

Photo: Humanoid robots of the children size league compete during the RoboCup 2006 football world championships final at the Congress Centre on June 18, 2006 in Bremen, Germany. (Photo by Malte Christians/Bongarts/Getty Images)

In this Friday, December 5, 2014 photo, Iranian volunteer Asal Moghaddam plays with dogs at the Vafa Animal Shelter in the city of Hashtgerd 43 miles (73 kilometers) west of the capital Tehran, Iran. More than 500 dogs find care and affection at the Vafa Animal Shelter, which was established through an endowment in 2004 and is the country’s only licensed animal refuge. (Photo by Vahid Salemi/AP Photo)

Clowns take part in the annual pilgrimage to the Basilica of Our Lady Guadalupe to pay homage to the Virgin of Guadalupe in Mexico City December 16, 2014. Dressed in colourful costumes, hundreds of clowns from all over Mexico walked towards the Basilica to give thanks to the virgin for the work they have received. (Photo by Carlos Jasso/Reuters)

A participant wearing a tiger mask performs during the “Paseo del Pendon”, a traditional artistic march in Chilpancingo, December 21, 2014. The “Paseo del Pendon” (walk banner) is a traditional celebration in the streets of Chilpancingo to mark the begin of the the year-end festivities in the city. (Photo by Jorge Dan Lopez/Reuters)

A reveller wearing a golden cape celebrates as the sun rises during the winter solstice at Stonehenge on Salisbury plain in southern England December 22, 2014. The winter solstice is the shortest day of the year, and the longest night of the year. (Photo by Dylan Martinez/Reuters)