A visitor kneels down nex to an iCub robot made by the Italian Institute of Technology at the scientists congress IROS 2015 in Hamburg, Germany October 2, 2015. The robot congress is organized by TAMS group (Technical Aspects of Multimodal Systems) of Hamburg's university. (Photo by Fabian Bimmer/Reuters)

The CBRE Urban Photographer of the Year competition – now in its ninth year – encourages professional and amateur photographers to capture cities at work. Here: Dog Walker – 15:00. The competition allows photographers to enter up to 24 images, one representing each hour of the day. (Photo by Johanna Siegmann)

A surfer runs down the beach past hundreds of Barbie dolls comprising the sculpture 'Wave 2' by West Australian artist Annette Thas on Tamarama Beach during the 19th annual Sculptures by the Sea exhibition in Sydney, October 23, 2015. Sydney's coastal walk between Bondi and Tamarama has been transformed into a temporary sculpture park featuring over 100 sculptures from Australian and international artists, billed as the largest free sculpture exhibition in the world. (Photo by Jason Reed/Reuters)

Bangladeshi Muslim devotees arrive in an over-crowded train to attend the final day of an Islamic congregations' first phase in Tongi, 20 kilometers (13 miles) north of Dhaka, Bangladesh, Sunday, January 10, 2016. The second phase of the annual event, one of the world's largest congregations of Muslims is scheduled to begin Friday. (Photo by A.M. Ahad/AP Photo)

Visitors review their cell phone photos of an installation called “Plexus A1” by artist Gabriel Dawe, one of nine large-scale art installations displayed at the “Wonders” exhibit at the Renwick Art Gallery in Washington, DC, Wednesday, January 13, 2016. Built in the 1860s, the Renwick was the first American building to be designed specifically as an art museum; it recently reopened after a two year renovation. (Photo by Jim Lo Scalzo/EPA)

Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

People watch police destroy confiscated illegal firecrackers in Shenyang, Liaoning province, China, January 29, 2016. (Photo by Reuters/Stringer)

Balinese girls in traditional costumes gather during a parade for this year's last sundown in Bali island, Indonesia Thursday, December 31, 2015. (Photo by Firdia Lisnawati/AP Photo)