Humanoid robots compete in a group match of the 20th RoboCup in Leipzig, Germany, June 30, 2016. About 3,500 participants from 45 countries and regions compete in the robot world championship until 04 July. (Photo by Sebastian Willnow/EPA)

Traditional trumpeters perform during the durbar festival on the second day of Eid-al-Fitr celebrations in Nigeria's northern city of Kano, July 7, 2016. The Durbar festival begins with prayers, followed by a parade of the Emir and his entourage on horses, accompanied by music players, and ending at the Emir's palace. The Durbar festival had been in hausaland for more than 500 years. It was introduced by sarki muhammadu rumfa of kano in the late 14th century, as a way of demonstrating military power and skills before going to war. The festival is also an opportunity for local leaders to pay homage to emir throughout the jahi cheering. (Photo by Akintunde Akinleye/Reuters)

Just a week before Rio de Janeiro hosts South America's first Olympics, city residents expressed mixed feelings about the cost and security of the Games, while holding out hope they will bring joy to a nation facing economic and political crises. The conflicted thoughts mirror a recent survey by the Datafolha polling group showing that half of Brazilians were opposed to holding the Games, while 63 percent think the costs of hosting the event will outweigh benefits. (Photo by Pilar Olivares/Reuters)

A fragment of a Koran manuscript is seen in the library at the University of Birmingham in Britain July 22, 2015. A British university said on Wednesday that fragments of a Koran manuscript found in its library were from one of the oldest surviving copies of the Islamic text in the world, possibly written by someone who might have known Prophet Mohammad. Radiocarbon dating indicated that the parchment folios held by the University of Birmingham in central England were at least 1,370 years old, which would make them one of the earliest written forms of the Islamic holy book in existence. (Photo by Peter Nicholls/Reuters)

In this Monday, July 20, 2015 photo, Bill Lattin, the Southern California Timing Association president and Speed Week race director, stands in the Bonneville Salt Flats in Utah. A small city of tents, trailers and thousands of visitors appears almost every August in the Utah desert to watch cars, motorcycles and anything with wheels rocket across gleaming white sheets of salt at speeds of 400 mph. But wet weather has forced the cancellation of Speed Week for the second straight year and revived a debate about whether nearby mining is depleting the Bonneville Salt Flats of their precious resource. (Photo by Rick Bowmer/AP Photo)

Migrants with a stick, stones and knife fight with each other after a brawl erupted over a place in an overcrowded train heading to the Serbian border at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 14 August 2015. The number of migrants passing through Macedonia increases day by day, local sources said. From the beginning of the year to mid-June 2015, nearly 160,000 migrants landed in the southern European countries, mainly Greece and Italy, on their way to wealthier countries in Western and Northern Europe, according to estimates by the International Organization for Migration (IOM). (Photo by Georgi Licovski/EPA)

Migrants with a stick, stones and knife fight with each other after a brawl erupted over a place in an overcrowded train heading to the Serbian border at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 14 August 2015. (Photo by Georgi Licovski/EPA/EFE)

Painted eggshell displayed at Wayan Sadra's workshop on April 14, 2014 in Sukawati, Gianyar, Bali, Indonesia. 50-year-old Wayan Sadra got the idea to start his eggshell painting business, after his niece who worked in a five star hotel asked for his help to paint on an egg for an Easter egg competition. Now the business he started in 1997 attracts customers for his painted eggs from Germany, France, Italy, and the Netherlands. Sadra usually experiences a surge in sales ahead of Easter. (Photo by Putu Sayoga/Getty Images)